The rooting and growth of frozen cassava under different chemical treatments were studied.The result has demonstrated that disinfection effect could increase rooting rate and seedling emergence rate of cassava seed st...The rooting and growth of frozen cassava under different chemical treatments were studied.The result has demonstrated that disinfection effect could increase rooting rate and seedling emergence rate of cassava seed stem and decrease the rate of mildew.The sportak treatment could generate better effect(rooting rate and seedling emergence rate were 63%,the mildew rate of stem was 28%).Among different rooting reagents,Genwang+lime treatment generated better effect on rooting rate and emergence rate of frozen cassava than these of other groups and control group.It was concluded from the effects of different rooting reagents on growth of seed stem that Genwang+lime treatment could promote elongation and growth of cassava significantly(the mean plant height of experimental groups inceased 8.58 cm compared with that of control group) while paclobutrazol+lime generated the best effect on crassation of stem(the stem diameter of experimental group increased 0.4 cm compared with that of control group).展开更多
[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava （M...[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava （M1） and sole cropping of peanut （M2） as control groups, effects of intercropping of cassava with 1 row, 2 rows and 3 rows of peanut （M3, M4 and M5）on crop growth, yields and economic benefit were studied. [Result] Intercropping affected both growth and yields of cassava and peanut. Growth competition existed between cassava and peanut, and plant heights of cassava and peanut changed similarly. In late stages of intercropping, treatments M1, M2 and M5 showed higher plant heights under no nitrogen application, while treatment M3 and M4 exhibited higher plant heights under nitrogen application; intercropping improved leaf temperature, but no obvious law could be observed among different intercropping treatments; and intercropping improved total dry matter amount, which was the highest in M5 in root expanding stage and on the 30th day of the expanding stage, and the highest in M4 on the 60th day of the expanding stage. Intercropping reduced the yield of single plant, but improved the economic benefit of red upland soil; and under no nitrogen application and nitrogen application, cassava yields decreased by 25.35% and 14.55%, respectively, peanut yields decreased by 28.76% and 52.60%, respectively, while economic benefit increased by 72.90% and 56.82%, respectively. [Conclusion] Compared with sole cropping, interplanting cassava with 1 row, 2 rows or 3 rows of peanut could all improve economic benefit, and the economic benefit increased with number of rows of interplanted peanut increasing.展开更多
The research explored effects of cultivation methods on growth, yield and quality of cassava. The results showed that the mulching treatment by direct seed- ing, the mulching treatment by transplanting, and the expose...The research explored effects of cultivation methods on growth, yield and quality of cassava. The results showed that the mulching treatment by direct seed- ing, the mulching treatment by transplanting, and the exposed treatment by trans- planting performed excellently in bringing seedling stage forward, improving germina- tion rate, yield and quality. For example, seedling emergence stages were 36, 31 and 31 d earlier; germination rates improved by 19.24%, 14.29% and 14.29%; yields grew by 41.98%, 26.72% and 11.45%; starch contents increased by 3.50%, 2.10% and 1.40%, respectively. Therefore, cassava in the mulching treatment by direct seeding is characterized by earlier seedling emergence stage, high germination rate, high yield and quality.展开更多
In this study,11 cultivars of cassava（Manihot esculenta Crantz） were taken as materials to determine the starch contents and the ability to produce ethanol with uncooked and cooked materials.The results showed that ...In this study,11 cultivars of cassava（Manihot esculenta Crantz） were taken as materials to determine the starch contents and the ability to produce ethanol with uncooked and cooked materials.The results showed that the starch content differed among different cultivars.Among the 11 cultivars,SC9 had the highest starch content（82.33%）.The ethanol yield of cooked material was significantly higher than that of uncooked material.Moreover,there was a significant difference in ethanol yield among different cultivars.For the uncooked materials,H680 produced the most ethanol yield（9.7%）;while for the cooked materials,H609 produced the most ethanol yield（13.8%）.展开更多
[Objective] In this study,the climatic features and overwintering sage storage methods of seed-stem of cassava in cassava-planting areas were investigated aiming at providing a technical guidance for sustainable devel...[Objective] In this study,the climatic features and overwintering sage storage methods of seed-stem of cassava in cassava-planting areas were investigated aiming at providing a technical guidance for sustainable development of cassava industry in China.[Method] The seed-stem of cassava was overwintered through keeping in field,piling up in the open air,burying in soil or piling up in greenhouses in Hepu,Nanning and Laibin of Guangxi,Hunan and Zhejiang.After the beginning of spring,the survival buds in seed stem of cassava were counted.And then the survival rates of buds were calculated for different storage methods.[Result] In Hepu,where the seed-stem of cassava was piled up in the open air for overwintering,the survival rates of buds were all higher than 90.00%.In particular,the survival rate of buds in seed-stem of cassava that was buried shallowly in the open field was highest（94.38%）.In Nanning,the seed-stem of cassava that was stored in greenhouses had the highest survival rate（94.98%） of buds.In Laibin,the seed-stem of cassava was usually stacked in greenhouses.Thus the survival rates of buds were almost all higher than 89.60%.Particularly,the survival rate of buds in seed-stem of cassava that was buried horizontally in soil and covered with sugarcane leaves reached the peak（98.79%）.In Jiangyong and Hangzhou,the seedstem of cassava was stored in specific facilities.So the survival rates of buds were relatively high.[Conclusion] In the frost-free areas south of 21.6° N（south of Maoming（Guangdong）-Hepu（Guangxi）-Jinghong（Yunnan））,the seed-stem of cassava can be buried shallowly in the open air or stacked and covered with film.In the light to heavy-frost areas（21.6° N-23.8° N,south of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan））,the seed-stem of cassava can be stacked in greenhouses,stacked and covered with film in the open air or buried vertically in greenhouses.In the heavy-frost areas and low-temperature areas north of 23.8° N（north of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan） to HunanJiangxi-Zhejiang）,the seed-stem of cassava can be stored in coldness-resistant caves or cellars or stacked vertically in greenhouses along with small sheds.展开更多
[Objective] In order to explore the yield potential of cassava, the responses of new cassava varieties to fertilizer quantity was investigated. [Method] A comparative experiment was carried out on 5 new fertilizer-tol...[Objective] In order to explore the yield potential of cassava, the responses of new cassava varieties to fertilizer quantity was investigated. [Method] A comparative experiment was carried out on 5 new fertilizer-tolerant high-yield cassava varieties（Guire 8, Guire 9, Guire 10, Xinxuan 048 and Guiken 09-26） with the normal-level fertilization groups of these varieties as controls. [Result] The results showed that：（1） increasing fertilizers could significantly improve the stem and leaf yield of cassava;（2） increasing fertilizers could reduce the dry matter content of cassava; and（3） different varieties differed in fertilizer tolerance, and the fertilizing amount should be determined according to specific varieties. [Conclusion] Guire 10 and Xinxuan 048 are suitable for being cultivated at a high fertilizer level, and the remaining three varieties（Guiken 09-26, Guire 8 and Guire 9） are suitable for being cultivated at a normal fertilizer level.展开更多
In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and...In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and its effects on the growth and development, yield and fruit quality of watermelon were investigated. The results showed that the cassava starch anaerobic fermentation liquid significant- ly promoted the vegetative and reproductive growth and improved the yield and fruit quality of watermelon. Compared with conventional fertilization, the application of cassava starch anaerobic fermentation both with COD concentration of 1 200 mg/L according to the amount of 150 t/hm2 promoted the growth of vines and leaves of watermelon plants, brought forward the flowering, fruiting and harvest of watermelon and significantly increased the fruit number, fruit weight, yield, fruit size, fruit shape index, soluble solid content, soluble sugar content, soluble protein content and Vita- min C content of watermelon. At the same time of improving the yield and quality of watermelon, cassava starch anaerobic fermentation liquid was turned into treasure as a liquid fertilizer. This study provides a new ideal for the yield and quality im- provement of watermelon and the wastewater treating of starch factories.展开更多
Cassava productivity is hampered by pests and diseases including cassava<span style="font-family:;" "=""><span style="font-family:Verdana;"> mosaic disease (CMD) and cass...Cassava productivity is hampered by pests and diseases including cassava<span style="font-family:;" "=""><span style="font-family:Verdana;"> mosaic disease (CMD) and cassava brown streak disease (CBSD).</span><b> </b><span style="font-family:Verdana;">The main ob</span><span style="font-family:Verdana;">jective of this study was to identify stable superior genotypes that combine</span><span style="font-family:Verdana;"> dis</span><span style="font-family:Verdana;">ease resistance and high yield. Sixteen cassava genotypes were planted in a</span> <span style="font-family:Verdana;">randomized complete block design with three replications for six planting </span><span style="font-family:Verdana;">seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (</span></span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;">< 0.001) effects of genotype, environment, and genotype-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">by-environment (</span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;">) interactions were observed for all traits studied. Per</span><span style="font-family:Verdana;">cent sum of squares (SS) due to environment (12.66% - 85.23%) was the</span><span style="font-family:Verdana;"> highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) </span><span><span style="font-family:Verdana;">was highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (26.14% - 35.91%) for CBSD foliar and root</span></span><span style="font-family:Verdana;"> symptoms indicating that the environment and </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.</span></span>展开更多
Cassava is a multi-purpose crop for food, feed and industrial raw materi- als （starch, modified starch and ethanol fuel）. Cassava leaf, an important by-product of cassava industry, is rich in protein, minerals and f...Cassava is a multi-purpose crop for food, feed and industrial raw materi- als （starch, modified starch and ethanol fuel）. Cassava leaf, an important by-product of cassava industry, is rich in protein, minerals and flavonoids. This article reviews the utilization of cassava leaf in the production of food, animal feed and antioxidants in recent years, analyzes the effects of anti-nutritional factors and extraction of an- tioxidative flavonoids on the utilization of cassava leaf, finally puts forward the main problems in the utilization of cassava leaf, to provide a theoretical basis for the ba- sic research of cassava leaf.展开更多
Cassava mosaic disease （CMD）, the most important disease of cassava （Manihot esculenta Crantz） is a potential threat to Africa＇s cassava production. The disease is embedded in most landraces resulting in low yiel...Cassava mosaic disease （CMD）, the most important disease of cassava （Manihot esculenta Crantz） is a potential threat to Africa＇s cassava production. The disease is embedded in most landraces resulting in low yields. Host plant resistance has been found to be the best control strategy. A breeding programme using genetic hybridisation and Marker Assisted Selection was initiated in 2007 to improve the resistance levels of farmer-preferred landraces and reduce the long breeding cycle for developing improved cassava varieties. Thirty farmer-preferred landraces were selected and crossed with a high yielding and mosaic resistant cultivar （TMEI l） from International Institute of Tropical Agriculture （IITA）. The resultant progenies found to have a reasonable level of resistance （score, 1-3） to the CMD were AW 18, 273 Nyamebekyere, NK 43, AW 3, NK 26, K 25, Dabodabo, Ahwengyankwa, 674 Debor, Degarti, Agric Bankye, and NK 57. These resultant progenies were backcrossed to the resistant cultivar. The backcross one （BC l） progenies totaling 224 were screened with molecular markers that are associated to the CMD 2 gene. De-oxyribonucleic Acid （DNA） was extracted from leaves of the 224 BC1 progenies and 13 parents. Two Simple Sequence Repeats （SSR） markers （SSY28 and NSl58） and one Sequenced Characterized Amplified Region （SCAR） marker RME1, were used to screen and select for the resistant BC l progenies. Marker Assisted Selection （MAS） revealed that 82% of the genotypes had at least a marker allele for the CMD2 gene, indicating resistance. The study further revealed that by using MAS, the breeding cycle of cassava in the generation of varieties could be reduced from 8 years to 2 years. The resistant genotypes identified will be evaluated for yield and starch cooking quality in future breeding work.展开更多
Cassava （Manihot esculenta Crantz） production in Akwa Ibom State is limited by cassava anthracnose disease （CAD） which causes enormous losses in planting materials. Survey of the disease was conducted in the wet a...Cassava （Manihot esculenta Crantz） production in Akwa Ibom State is limited by cassava anthracnose disease （CAD） which causes enormous losses in planting materials. Survey of the disease was conducted in the wet and dry seasons in six major cassava-growing areas （Essien Udim, Ikono, Itu, Nsit Atai, Oruk Anam and Uyo） of the State to determine the incidence and severity of the disease. Ten commonly grown cassava varieties were then screened in the greenhouse by inoculating each variety with the spore suspension of virulent isolate of the cassava anthracnose pathogen. Disease severity was assessed using size of lesions on the inoculated plants and defoliation caused by the infection. Results of the survey showed that Nsit Atai is a high infection area for CAD. It recorded the highest disease incidence and severity in both the wet season （36.59% and 3.52） and dry season （9.26% and 2.20）, respectively. The mean disease incidence （24.10%） and severity （3.23） for the six study areas were higher in the wet season indicating the importance of this season in the occurrence of CAD. Results of the screening test showed that TMS 98/30572 was resistant to the disease. The small lesion size （5.00 mm） observed in this variety would ensure less stem disruption and timely delivery of resources to the actively growing points. The low defoliation （5,65%） observed in the same variety would enhance the photosynthetic capacity of the plant. Therefore, TMS 98/30572 may be recommended to cassava farmers in Akwa Ibom State.展开更多
The study was conducted by researchers of the Research Center for Agricultural Energy and Machinery （CAEM） of the Ho Chi Minh City Nong Lam University （NLU） with the objectives of researching on drying ways for ca...The study was conducted by researchers of the Research Center for Agricultural Energy and Machinery （CAEM） of the Ho Chi Minh City Nong Lam University （NLU） with the objectives of researching on drying ways for cassava and of evaluating the adaptability of the reversible-airflow dryers in drying of cassava. The results obtained were as follows： done with thin-layer drying experiments, deep-layer drying experiments in the lab, and conducted drying experiments at the cassava dryer in actual production scale with two capacity sizes of 8 tons/batch and 16 tons/batch, that operates based on principle of reversible-airflow drying （SRA dryers）. By the means of drying experiments, the performance of the SRA dryers such as optimal drying temperature, drying time, drying airflow reversal timing, moisture content uniformity of the sliced cassava mass after finishing drying process, drying cost, etc. was defined, the optimal drying temperature was 70 ~C, the total actual drying time for finishing one batch was 25-28 hours, applicable time for drying airflow reversal was after drying 16 hours since startup, the deviation in moisture content of the cassava mass after drying was just 2%-3%, the drying costs （per one kg of dried cassava） calculated were in turns VND407/kg at the SRA-8 dryer （8 tons/batch）, and VND351/kg at the SRA-16 dryer （16 tons/batch）. Obviously, comparing with the sale price of dry cassava at present, these levels of drying cost are accounting for 7%-10%, which are suitable and acceptable. Thus, investment of the dryers for sliced cassava would be effective and contribute to bring more income for Vietnamese cassava farmers and dryer end-users.展开更多
Cassava regarded as a white gold of Africa is driving the agricultural commercialization and industrialization with small to medium technologies in Uganda. There is an over-whelming demand for high quality cassava flo...Cassava regarded as a white gold of Africa is driving the agricultural commercialization and industrialization with small to medium technologies in Uganda. There is an over-whelming demand for high quality cassava flour （HQCF） by Bakeries, beverage industry, paper board and composite end markets. The end market for HQCF dictates on its quality attributes and rewards for its quality in terms of price offered within their minimum standards. However, obtaining sustainable amounts of HQCF for these markets calls for devoted efforts. Limited types of HQCF processing technologies exist and if they exist, their efficiency, costs and sustainability are not well understood. We evaluated high quality cassava drying technologies in Northern and Eastern Uganda in two years using naturally ventilated wooden screen solar drying structures and open air sun drying structures. Naturally ventilated wooden screen solar dryers produced clean dry high quality cassava chips free off insect and bird contamination and caused faster drying to less than 14.3% MC in 1.5 hours than open outside drying conditions. We recommend naturally ventilated wooden screen solar dryers for small and medium cassava processors during dry and rainy season. Halftone to one tone cassava chips dryers per day drying unit can cost one 2,258-4,338 USD to make it functional. Also open outside raised metallic racks with black surface can give good results on a good sunny day especially for starters on small scale basis. A small durable unit of 150 kilograms per day can be made with 500 USD.展开更多
Background: Cassava tuber crop is a staple food rich in carbohydrates and utilized in various forms by millions of Nigerians. The storage root of the cassava contains linamarin, a cyanogenic glycoside that is easily h...Background: Cassava tuber crop is a staple food rich in carbohydrates and utilized in various forms by millions of Nigerians. The storage root of the cassava contains linamarin, a cyanogenic glycoside that is easily hydrolyzed to release cyanide salt compounds which is toxic to the nervous system especially the optic nerve, sometimes leading to optic neuropathy and visual impairment. Aim: The aim of this study is to find out the impact of selected processing methods of high-level cyanide in cassava on optic neuropathy in Wistar albino rats. Methodology: Twenty-four Wistar albino rats were fed with different concentration and duration of predetermined high-cyanide content cassava root cultivar which was processed using different processing methods adopted by various communities in Rivers State, Nigeria (for human consumption). A control group of 3 Wistar albino rats was fed with normal “Growth Mesh” meals. The pre and post weights of the animals and the fundoscopic optic nerve status of the rats were evaluated after 30 and 60 days. SPSS Version 25 was employed for descriptive and inferential statistical analyses. A p-value of ≤0.05 was considered statistically significant. Results: The Cassava species available in Rivers State have high cyanide content (2336.79 mg CN<sup>-</sup>/kg dry weight of cassava). There was statistically significant reduction in the cyanide content (p = 0.000) depending on the various common processing methods (into garri for human consumption): 24 hours, 48 hours, fermentation;with and without red palm oil additive. The individual weights as well as the mean weight of the 24 rats in the experimental group increased gradually from the first week to the 9<sup>th</sup> week with a slight weight reduction on the third and fourth weeks which was not statistically significant (p = 0.092). However, there was a steady increase in the weights of the animals in the control group throughout the 9 weeks. Varying degrees of optic neuropathy occurred, worse with the rats that had 24-hour fermented cassava twice daily for 60 days. The intra and inter group differences in the optic disc changes was statistically significant (p = 0.000). Conclusion: Longer duration of processing cassava roots into garri for human consumption reduces its cyanide content and minimizes the adverse impact on the optic nerve.展开更多
The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an acc...The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.展开更多
Cassava(Manihot esculenta Crantz) is an important root crop worldwide. It exhibits substantial differential genotypic responses to varying environmental conditions, a phenomenon termed genotype × environment inte...Cassava(Manihot esculenta Crantz) is an important root crop worldwide. It exhibits substantial differential genotypic responses to varying environmental conditions, a phenomenon termed genotype × environment interaction(GEI). A significant GEI presents challenges in the selection of superior genotypes. The objective of this study was to examine the effect of genotype,environment and GEI on early fresh storage root yield(FSRY) and related traits in cassava.Accordingly, 12 cassava genotypes were evaluated in a randomised complete block design at three contrasting locations(Jinja, Nakasongola and Namulonge) in Uganda. Trials were harvested nine months after planting and the data collected were analysed using the additive main effects and multiplicative interaction(AMMI) model. The AMMI analysis of variance showed significant variation among genotypes for early FSRY and all other traits assessed.Locations were significantly different for all traits except for cassava brown streak disease root necrosis. The GEI effect was non-significant for early FSRY, but significant for other traits. For early FSRY, 48.5% of the treatment sum of squares was attributable to genotypes, 27.3% to environments, and 24.1% to GEI, indicating a predominance of genotypic variation for this trait.Predominance of genotypic variation was also observed for all the other traits. A majority of the genotypes(67%) had low interaction effects with locations for early FSRY, with Akena, CT2, CT4 and NASE14 being the most stable genotypes for the trait. Significant negative correlation was observed between cassava mosaic disease severity and early FSRY and storage root number,indicating significant negative effects of cassava mosaic disease on early FSRY and stability in cassava. The information generated will inform future selection initiatives for superior early-yielding cassava genotypes combining resistance to cassava mosaic and brown streak diseases in Uganda.展开更多
Cassava is an important tropical cash crop. Severe drought stresses affect cassava productivity and quality, and cause great economic losses in agricultural production. Enhancing the drought tolerance of cassava can e...Cassava is an important tropical cash crop. Severe drought stresses affect cassava productivity and quality, and cause great economic losses in agricultural production. Enhancing the drought tolerance of cassava can effectively improve its yield. Long non-coding RNAs(lncRNAs) are present in a wide variety of eukaryotes. Recently, increasing evidence has shown that lncRNAs play a critical role in the responses to abiotic stresses. However, the function of cassava lncRNAs in the drought response remains largely unknown. In this study, we identified a novel lncRNA, DROUGHT-INDUCED INTERGENIC lncRNA(DIR). Gene expression analysis showed that DIR was significantly induced by drought stress treatment, but did not respond to abscisic acid(ABA) or jasmonic acid(JA) treatments. In addition, overexpression of the DIR gene enhanced proline accumulation and drought tolerance in transgenic cassava. RNA-seq analysis revealed that DIR preferentially affected drought-related genes that were linked to transcription and metabolism. Moreover, RNA pull-down mass spectrometry analysis showed that DIR interacted with 325 proteins. A protein–protein interaction(PPI)analysis found a marked enrichment in proteins associated with the mRNA export and protein quality control pathways.Collectively, these results suggest that DIR and its interacting proteins that regulate mRNA or protein metabolism are involved in mediating the drought stress response. Thus, regulating DIR expression has potential for improving cassava yield under drought conditions.展开更多
Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role ...Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.展开更多
Cassava starch-based superabsorbent polymer was successfully synthesized using a new technology that based on modification of a Haake twin-roll mixer as reactor. The cassava starch was first gelatinized then modified ...Cassava starch-based superabsorbent polymer was successfully synthesized using a new technology that based on modification of a Haake twin-roll mixer as reactor. The cassava starch was first gelatinized then modified by grafting under external shear stress in the reactor. The torque and temperature curves as a function of time can reflect the variations in the reactor and also offer some information about the copolymerization reaction. The advantages of this system include starch modification can be carried out （l） with high starch concentration, （2） under controlled ticne and （3） smaller amount of sample （60 g） required. The technology provides useful guides for reactive extrusion. The starch grafted composites were characterized by Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （NMR） and thermal gravimetric analysis （TGA）. The TGA was also used for determining the percentage of grafting ratio. The results show that the cassava starch has been successfully grafted with acrylamide then crosslinked by N,N＇-methylene-bisacrylamide using this reactor. The ultimate water absorbent capacity of the cassava-based superabsorbent polymer impacted by various pH values illustrated that the acid and basic solutions inhibit the ability of imbibing water. Additionally, gel properties of the cassava-based superabsorbent polymer were investigated. It can be concluded that the structure of cassava gel is stable, while the three dimensional network of cassava-based superabsorbent polymer is rigid but its structure could not resist external force effectively and everlastingly since G＇ was decreased with increasing amplitude.展开更多
Soy protein isolate and egg white protein were added to cassava-banana gluten-free pasta and the effects on the nutritional quality,digestibility properties,protein digestibility corrected amino acid(PDCAA),and sensor...Soy protein isolate and egg white protein were added to cassava-banana gluten-free pasta and the effects on the nutritional quality,digestibility properties,protein digestibility corrected amino acid(PDCAA),and sensory acceptance of the pasta was observed.Banana-cassava composite flour(75:25)was blended with soy protein isolate or egg white protein at the following rates:0,5,10,and 15 g/100 g flour.Cooked pasta samples were analysed for total phenolic content(TPC),antioxidant activity,amino acid profiles,protein content,starch digestibility,protein digestibility and protein digestibility corrected amino acid score(PDCAAS).Addition of both proteins decreased starch digestibility,increased protein digestibility,improved the balance of the amino acid profile,and PDCAAS whereas only soy protein isolate enhanced the TPC and antioxidant capacity of the banana-cassava pasta.An egg white protein-fortified banana-cassava pasta had better customer acceptance and purchase intent than soy protein isolate inclusion.展开更多
文摘The rooting and growth of frozen cassava under different chemical treatments were studied.The result has demonstrated that disinfection effect could increase rooting rate and seedling emergence rate of cassava seed stem and decrease the rate of mildew.The sportak treatment could generate better effect(rooting rate and seedling emergence rate were 63%,the mildew rate of stem was 28%).Among different rooting reagents,Genwang+lime treatment generated better effect on rooting rate and emergence rate of frozen cassava than these of other groups and control group.It was concluded from the effects of different rooting reagents on growth of seed stem that Genwang+lime treatment could promote elongation and growth of cassava significantly(the mean plant height of experimental groups inceased 8.58 cm compared with that of control group) while paclobutrazol+lime generated the best effect on crassation of stem(the stem diameter of experimental group increased 0.4 cm compared with that of control group).
基金Supported by Youth Innovation Fund of Jiangxi Sciences of Agricultural Sciences(2013CQN010)Earmarked Fund for China Agriculture Research System(CARS-12-jxyzq)~~
文摘[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava （M1） and sole cropping of peanut （M2） as control groups, effects of intercropping of cassava with 1 row, 2 rows and 3 rows of peanut （M3, M4 and M5）on crop growth, yields and economic benefit were studied. [Result] Intercropping affected both growth and yields of cassava and peanut. Growth competition existed between cassava and peanut, and plant heights of cassava and peanut changed similarly. In late stages of intercropping, treatments M1, M2 and M5 showed higher plant heights under no nitrogen application, while treatment M3 and M4 exhibited higher plant heights under nitrogen application; intercropping improved leaf temperature, but no obvious law could be observed among different intercropping treatments; and intercropping improved total dry matter amount, which was the highest in M5 in root expanding stage and on the 30th day of the expanding stage, and the highest in M4 on the 60th day of the expanding stage. Intercropping reduced the yield of single plant, but improved the economic benefit of red upland soil; and under no nitrogen application and nitrogen application, cassava yields decreased by 25.35% and 14.55%, respectively, peanut yields decreased by 28.76% and 52.60%, respectively, while economic benefit increased by 72.90% and 56.82%, respectively. [Conclusion] Compared with sole cropping, interplanting cassava with 1 row, 2 rows or 3 rows of peanut could all improve economic benefit, and the economic benefit increased with number of rows of interplanted peanut increasing.
基金Supported by the Earmarked Fund for China Agriculture Research System(CARS-12)~~
文摘The research explored effects of cultivation methods on growth, yield and quality of cassava. The results showed that the mulching treatment by direct seed- ing, the mulching treatment by transplanting, and the exposed treatment by trans- planting performed excellently in bringing seedling stage forward, improving germina- tion rate, yield and quality. For example, seedling emergence stages were 36, 31 and 31 d earlier; germination rates improved by 19.24%, 14.29% and 14.29%; yields grew by 41.98%, 26.72% and 11.45%; starch contents increased by 3.50%, 2.10% and 1.40%, respectively. Therefore, cassava in the mulching treatment by direct seeding is characterized by earlier seedling emergence stage, high germination rate, high yield and quality.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-12)Hunan Agricultural University Youth Science Foundation(12QN13)~~
文摘In this study,11 cultivars of cassava（Manihot esculenta Crantz） were taken as materials to determine the starch contents and the ability to produce ethanol with uncooked and cooked materials.The results showed that the starch content differed among different cultivars.Among the 11 cultivars,SC9 had the highest starch content（82.33%）.The ethanol yield of cooked material was significantly higher than that of uncooked material.Moreover,there was a significant difference in ethanol yield among different cultivars.For the uncooked materials,H680 produced the most ethanol yield（9.7%）;while for the cooked materials,H609 produced the most ethanol yield（13.8%）.
基金Supported by Scientist Program for Seedling Breeding of National Cassava IndustryTechnology System(CARS-12-gxwbh)Key Science and Technology Program ofGuangxi Province(1222014-2C)~~
文摘[Objective] In this study,the climatic features and overwintering sage storage methods of seed-stem of cassava in cassava-planting areas were investigated aiming at providing a technical guidance for sustainable development of cassava industry in China.[Method] The seed-stem of cassava was overwintered through keeping in field,piling up in the open air,burying in soil or piling up in greenhouses in Hepu,Nanning and Laibin of Guangxi,Hunan and Zhejiang.After the beginning of spring,the survival buds in seed stem of cassava were counted.And then the survival rates of buds were calculated for different storage methods.[Result] In Hepu,where the seed-stem of cassava was piled up in the open air for overwintering,the survival rates of buds were all higher than 90.00%.In particular,the survival rate of buds in seed-stem of cassava that was buried shallowly in the open field was highest（94.38%）.In Nanning,the seed-stem of cassava that was stored in greenhouses had the highest survival rate（94.98%） of buds.In Laibin,the seed-stem of cassava was usually stacked in greenhouses.Thus the survival rates of buds were almost all higher than 89.60%.Particularly,the survival rate of buds in seed-stem of cassava that was buried horizontally in soil and covered with sugarcane leaves reached the peak（98.79%）.In Jiangyong and Hangzhou,the seedstem of cassava was stored in specific facilities.So the survival rates of buds were relatively high.[Conclusion] In the frost-free areas south of 21.6° N（south of Maoming（Guangdong）-Hepu（Guangxi）-Jinghong（Yunnan））,the seed-stem of cassava can be buried shallowly in the open air or stacked and covered with film.In the light to heavy-frost areas（21.6° N-23.8° N,south of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan））,the seed-stem of cassava can be stacked in greenhouses,stacked and covered with film in the open air or buried vertically in greenhouses.In the heavy-frost areas and low-temperature areas north of 23.8° N（north of Qingyuan（Guangdong）-Laibin（Guangxi）-Lincang（Yunnan） to HunanJiangxi-Zhejiang）,the seed-stem of cassava can be stored in coldness-resistant caves or cellars or stacked vertically in greenhouses along with small sheds.
基金Supported by the Earmarked Fund for China Agriculture Research System(CARS-12-cssy)~~
文摘[Objective] In order to explore the yield potential of cassava, the responses of new cassava varieties to fertilizer quantity was investigated. [Method] A comparative experiment was carried out on 5 new fertilizer-tolerant high-yield cassava varieties（Guire 8, Guire 9, Guire 10, Xinxuan 048 and Guiken 09-26） with the normal-level fertilization groups of these varieties as controls. [Result] The results showed that：（1） increasing fertilizers could significantly improve the stem and leaf yield of cassava;（2） increasing fertilizers could reduce the dry matter content of cassava; and（3） different varieties differed in fertilizer tolerance, and the fertilizing amount should be determined according to specific varieties. [Conclusion] Guire 10 and Xinxuan 048 are suitable for being cultivated at a high fertilizer level, and the remaining three varieties（Guiken 09-26, Guire 8 and Guire 9） are suitable for being cultivated at a normal fertilizer level.
文摘In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and its effects on the growth and development, yield and fruit quality of watermelon were investigated. The results showed that the cassava starch anaerobic fermentation liquid significant- ly promoted the vegetative and reproductive growth and improved the yield and fruit quality of watermelon. Compared with conventional fertilization, the application of cassava starch anaerobic fermentation both with COD concentration of 1 200 mg/L according to the amount of 150 t/hm2 promoted the growth of vines and leaves of watermelon plants, brought forward the flowering, fruiting and harvest of watermelon and significantly increased the fruit number, fruit weight, yield, fruit size, fruit shape index, soluble solid content, soluble sugar content, soluble protein content and Vita- min C content of watermelon. At the same time of improving the yield and quality of watermelon, cassava starch anaerobic fermentation liquid was turned into treasure as a liquid fertilizer. This study provides a new ideal for the yield and quality im- provement of watermelon and the wastewater treating of starch factories.
文摘Cassava productivity is hampered by pests and diseases including cassava<span style="font-family:;" "=""><span style="font-family:Verdana;"> mosaic disease (CMD) and cassava brown streak disease (CBSD).</span><b> </b><span style="font-family:Verdana;">The main ob</span><span style="font-family:Verdana;">jective of this study was to identify stable superior genotypes that combine</span><span style="font-family:Verdana;"> dis</span><span style="font-family:Verdana;">ease resistance and high yield. Sixteen cassava genotypes were planted in a</span> <span style="font-family:Verdana;">randomized complete block design with three replications for six planting </span><span style="font-family:Verdana;">seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (</span></span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;">< 0.001) effects of genotype, environment, and genotype-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">by-environment (</span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;">) interactions were observed for all traits studied. Per</span><span style="font-family:Verdana;">cent sum of squares (SS) due to environment (12.66% - 85.23%) was the</span><span style="font-family:Verdana;"> highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) </span><span><span style="font-family:Verdana;">was highest followed by </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> (26.14% - 35.91%) for CBSD foliar and root</span></span><span style="font-family:Verdana;"> symptoms indicating that the environment and </span><i><span style="font-family:Verdana;">G</span><sup><span style="font-family:Verdana;">*</span></sup><span style="font-family:Verdana;">E</span></i><span style="font-family:Verdana;"> greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.</span></span>
文摘Cassava is a multi-purpose crop for food, feed and industrial raw materi- als （starch, modified starch and ethanol fuel）. Cassava leaf, an important by-product of cassava industry, is rich in protein, minerals and flavonoids. This article reviews the utilization of cassava leaf in the production of food, animal feed and antioxidants in recent years, analyzes the effects of anti-nutritional factors and extraction of an- tioxidative flavonoids on the utilization of cassava leaf, finally puts forward the main problems in the utilization of cassava leaf, to provide a theoretical basis for the ba- sic research of cassava leaf.
文摘Cassava mosaic disease （CMD）, the most important disease of cassava （Manihot esculenta Crantz） is a potential threat to Africa＇s cassava production. The disease is embedded in most landraces resulting in low yields. Host plant resistance has been found to be the best control strategy. A breeding programme using genetic hybridisation and Marker Assisted Selection was initiated in 2007 to improve the resistance levels of farmer-preferred landraces and reduce the long breeding cycle for developing improved cassava varieties. Thirty farmer-preferred landraces were selected and crossed with a high yielding and mosaic resistant cultivar （TMEI l） from International Institute of Tropical Agriculture （IITA）. The resultant progenies found to have a reasonable level of resistance （score, 1-3） to the CMD were AW 18, 273 Nyamebekyere, NK 43, AW 3, NK 26, K 25, Dabodabo, Ahwengyankwa, 674 Debor, Degarti, Agric Bankye, and NK 57. These resultant progenies were backcrossed to the resistant cultivar. The backcross one （BC l） progenies totaling 224 were screened with molecular markers that are associated to the CMD 2 gene. De-oxyribonucleic Acid （DNA） was extracted from leaves of the 224 BC1 progenies and 13 parents. Two Simple Sequence Repeats （SSR） markers （SSY28 and NSl58） and one Sequenced Characterized Amplified Region （SCAR） marker RME1, were used to screen and select for the resistant BC l progenies. Marker Assisted Selection （MAS） revealed that 82% of the genotypes had at least a marker allele for the CMD2 gene, indicating resistance. The study further revealed that by using MAS, the breeding cycle of cassava in the generation of varieties could be reduced from 8 years to 2 years. The resistant genotypes identified will be evaluated for yield and starch cooking quality in future breeding work.
文摘Cassava （Manihot esculenta Crantz） production in Akwa Ibom State is limited by cassava anthracnose disease （CAD） which causes enormous losses in planting materials. Survey of the disease was conducted in the wet and dry seasons in six major cassava-growing areas （Essien Udim, Ikono, Itu, Nsit Atai, Oruk Anam and Uyo） of the State to determine the incidence and severity of the disease. Ten commonly grown cassava varieties were then screened in the greenhouse by inoculating each variety with the spore suspension of virulent isolate of the cassava anthracnose pathogen. Disease severity was assessed using size of lesions on the inoculated plants and defoliation caused by the infection. Results of the survey showed that Nsit Atai is a high infection area for CAD. It recorded the highest disease incidence and severity in both the wet season （36.59% and 3.52） and dry season （9.26% and 2.20）, respectively. The mean disease incidence （24.10%） and severity （3.23） for the six study areas were higher in the wet season indicating the importance of this season in the occurrence of CAD. Results of the screening test showed that TMS 98/30572 was resistant to the disease. The small lesion size （5.00 mm） observed in this variety would ensure less stem disruption and timely delivery of resources to the actively growing points. The low defoliation （5,65%） observed in the same variety would enhance the photosynthetic capacity of the plant. Therefore, TMS 98/30572 may be recommended to cassava farmers in Akwa Ibom State.
文摘The study was conducted by researchers of the Research Center for Agricultural Energy and Machinery （CAEM） of the Ho Chi Minh City Nong Lam University （NLU） with the objectives of researching on drying ways for cassava and of evaluating the adaptability of the reversible-airflow dryers in drying of cassava. The results obtained were as follows： done with thin-layer drying experiments, deep-layer drying experiments in the lab, and conducted drying experiments at the cassava dryer in actual production scale with two capacity sizes of 8 tons/batch and 16 tons/batch, that operates based on principle of reversible-airflow drying （SRA dryers）. By the means of drying experiments, the performance of the SRA dryers such as optimal drying temperature, drying time, drying airflow reversal timing, moisture content uniformity of the sliced cassava mass after finishing drying process, drying cost, etc. was defined, the optimal drying temperature was 70 ~C, the total actual drying time for finishing one batch was 25-28 hours, applicable time for drying airflow reversal was after drying 16 hours since startup, the deviation in moisture content of the cassava mass after drying was just 2%-3%, the drying costs （per one kg of dried cassava） calculated were in turns VND407/kg at the SRA-8 dryer （8 tons/batch）, and VND351/kg at the SRA-16 dryer （16 tons/batch）. Obviously, comparing with the sale price of dry cassava at present, these levels of drying cost are accounting for 7%-10%, which are suitable and acceptable. Thus, investment of the dryers for sliced cassava would be effective and contribute to bring more income for Vietnamese cassava farmers and dryer end-users.
文摘Cassava regarded as a white gold of Africa is driving the agricultural commercialization and industrialization with small to medium technologies in Uganda. There is an over-whelming demand for high quality cassava flour （HQCF） by Bakeries, beverage industry, paper board and composite end markets. The end market for HQCF dictates on its quality attributes and rewards for its quality in terms of price offered within their minimum standards. However, obtaining sustainable amounts of HQCF for these markets calls for devoted efforts. Limited types of HQCF processing technologies exist and if they exist, their efficiency, costs and sustainability are not well understood. We evaluated high quality cassava drying technologies in Northern and Eastern Uganda in two years using naturally ventilated wooden screen solar drying structures and open air sun drying structures. Naturally ventilated wooden screen solar dryers produced clean dry high quality cassava chips free off insect and bird contamination and caused faster drying to less than 14.3% MC in 1.5 hours than open outside drying conditions. We recommend naturally ventilated wooden screen solar dryers for small and medium cassava processors during dry and rainy season. Halftone to one tone cassava chips dryers per day drying unit can cost one 2,258-4,338 USD to make it functional. Also open outside raised metallic racks with black surface can give good results on a good sunny day especially for starters on small scale basis. A small durable unit of 150 kilograms per day can be made with 500 USD.
文摘Background: Cassava tuber crop is a staple food rich in carbohydrates and utilized in various forms by millions of Nigerians. The storage root of the cassava contains linamarin, a cyanogenic glycoside that is easily hydrolyzed to release cyanide salt compounds which is toxic to the nervous system especially the optic nerve, sometimes leading to optic neuropathy and visual impairment. Aim: The aim of this study is to find out the impact of selected processing methods of high-level cyanide in cassava on optic neuropathy in Wistar albino rats. Methodology: Twenty-four Wistar albino rats were fed with different concentration and duration of predetermined high-cyanide content cassava root cultivar which was processed using different processing methods adopted by various communities in Rivers State, Nigeria (for human consumption). A control group of 3 Wistar albino rats was fed with normal “Growth Mesh” meals. The pre and post weights of the animals and the fundoscopic optic nerve status of the rats were evaluated after 30 and 60 days. SPSS Version 25 was employed for descriptive and inferential statistical analyses. A p-value of ≤0.05 was considered statistically significant. Results: The Cassava species available in Rivers State have high cyanide content (2336.79 mg CN<sup>-</sup>/kg dry weight of cassava). There was statistically significant reduction in the cyanide content (p = 0.000) depending on the various common processing methods (into garri for human consumption): 24 hours, 48 hours, fermentation;with and without red palm oil additive. The individual weights as well as the mean weight of the 24 rats in the experimental group increased gradually from the first week to the 9<sup>th</sup> week with a slight weight reduction on the third and fourth weeks which was not statistically significant (p = 0.092). However, there was a steady increase in the weights of the animals in the control group throughout the 9 weeks. Varying degrees of optic neuropathy occurred, worse with the rats that had 24-hour fermented cassava twice daily for 60 days. The intra and inter group differences in the optic disc changes was statistically significant (p = 0.000). Conclusion: Longer duration of processing cassava roots into garri for human consumption reduces its cyanide content and minimizes the adverse impact on the optic nerve.
基金supported by the National Key R&D Program of China(2017YFC1200600,2016YFC1201200 and 2015BAD08A16)the Science and Technology Innovation Program of CAAS(caascx-2013-2018-IAS)
文摘The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava,and its recent introduction into Asia has raised considerable alarm.To slow or prevent further invasion,an accurate,simple,and developmental-stage-independent detection method for P.manihoti is required.In the present study,a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I(SS-COI)marker was developed for rapid identification of P.manihoti.One pair of SS-COI primers(PMSSZW-1F and PMSSZW-1R)was designed based on sequence variations in the COI gene among P.manihoti and related mealybug species.Specificity of the primer pair was validated on 21 closely related species.Sensitivity tests were performed on four immature developmental stages and female adults.Efficacy tests demonstrated that at the relatively low concentration of(135.2±14.7)pgresuspended DNA,the specific fragment was detected in all replicates.Furthermore,the SS-COI primer pair was assayed on three populations of P.manihoti from major exporting countries of cassava.The PCR assay was proved to be a rapid,simple,and reliable molecular measure for the identification of P.manihoti.This tool will be useful for quarantine,monitoring,and management of this invasive pest.
基金funds from the Alliance for a Green Revolution in Africa through the African Centre for Crop Improvement
文摘Cassava(Manihot esculenta Crantz) is an important root crop worldwide. It exhibits substantial differential genotypic responses to varying environmental conditions, a phenomenon termed genotype × environment interaction(GEI). A significant GEI presents challenges in the selection of superior genotypes. The objective of this study was to examine the effect of genotype,environment and GEI on early fresh storage root yield(FSRY) and related traits in cassava.Accordingly, 12 cassava genotypes were evaluated in a randomised complete block design at three contrasting locations(Jinja, Nakasongola and Namulonge) in Uganda. Trials were harvested nine months after planting and the data collected were analysed using the additive main effects and multiplicative interaction(AMMI) model. The AMMI analysis of variance showed significant variation among genotypes for early FSRY and all other traits assessed.Locations were significantly different for all traits except for cassava brown streak disease root necrosis. The GEI effect was non-significant for early FSRY, but significant for other traits. For early FSRY, 48.5% of the treatment sum of squares was attributable to genotypes, 27.3% to environments, and 24.1% to GEI, indicating a predominance of genotypic variation for this trait.Predominance of genotypic variation was also observed for all the other traits. A majority of the genotypes(67%) had low interaction effects with locations for early FSRY, with Akena, CT2, CT4 and NASE14 being the most stable genotypes for the trait. Significant negative correlation was observed between cassava mosaic disease severity and early FSRY and storage root number,indicating significant negative effects of cassava mosaic disease on early FSRY and stability in cassava. The information generated will inform future selection initiatives for superior early-yielding cassava genotypes combining resistance to cassava mosaic and brown streak diseases in Uganda.
基金supported by the National Key Research and Development Program of China(2018YFD1000500,2019YFD1000500,and 2019YFD1001105)the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(1630052021026 and 1630052022008)+2 种基金the National Natural Science Foundation of China(31960440)the Hainan Provincial Natural Science Foundation of China(320MS097)the Natural Science Foundation of China(31701484)。
文摘Cassava is an important tropical cash crop. Severe drought stresses affect cassava productivity and quality, and cause great economic losses in agricultural production. Enhancing the drought tolerance of cassava can effectively improve its yield. Long non-coding RNAs(lncRNAs) are present in a wide variety of eukaryotes. Recently, increasing evidence has shown that lncRNAs play a critical role in the responses to abiotic stresses. However, the function of cassava lncRNAs in the drought response remains largely unknown. In this study, we identified a novel lncRNA, DROUGHT-INDUCED INTERGENIC lncRNA(DIR). Gene expression analysis showed that DIR was significantly induced by drought stress treatment, but did not respond to abscisic acid(ABA) or jasmonic acid(JA) treatments. In addition, overexpression of the DIR gene enhanced proline accumulation and drought tolerance in transgenic cassava. RNA-seq analysis revealed that DIR preferentially affected drought-related genes that were linked to transcription and metabolism. Moreover, RNA pull-down mass spectrometry analysis showed that DIR interacted with 325 proteins. A protein–protein interaction(PPI)analysis found a marked enrichment in proteins associated with the mRNA export and protein quality control pathways.Collectively, these results suggest that DIR and its interacting proteins that regulate mRNA or protein metabolism are involved in mediating the drought stress response. Thus, regulating DIR expression has potential for improving cassava yield under drought conditions.
基金supported by the China Agriculture Research System (CARS11-HNCX)the Major Science and Technology Plan of Hainan Province (ZDKJ2021012)+3 种基金the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences (1630052022008)the National Key Research and Development Program of China (2018YFD1000501)the National Natural Science Foundation of China (31501378)the Hainan Yazhou Bay Seed Lab (B21HJ0303)。
文摘Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.
基金financially supported by the National Natural Science Foundation of China(Nos.31130042,21174043,31301554 and 31101340)
文摘Cassava starch-based superabsorbent polymer was successfully synthesized using a new technology that based on modification of a Haake twin-roll mixer as reactor. The cassava starch was first gelatinized then modified by grafting under external shear stress in the reactor. The torque and temperature curves as a function of time can reflect the variations in the reactor and also offer some information about the copolymerization reaction. The advantages of this system include starch modification can be carried out （l） with high starch concentration, （2） under controlled ticne and （3） smaller amount of sample （60 g） required. The technology provides useful guides for reactive extrusion. The starch grafted composites were characterized by Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （NMR） and thermal gravimetric analysis （TGA）. The TGA was also used for determining the percentage of grafting ratio. The results show that the cassava starch has been successfully grafted with acrylamide then crosslinked by N,N＇-methylene-bisacrylamide using this reactor. The ultimate water absorbent capacity of the cassava-based superabsorbent polymer impacted by various pH values illustrated that the acid and basic solutions inhibit the ability of imbibing water. Additionally, gel properties of the cassava-based superabsorbent polymer were investigated. It can be concluded that the structure of cassava gel is stable, while the three dimensional network of cassava-based superabsorbent polymer is rigid but its structure could not resist external force effectively and everlastingly since G＇ was decreased with increasing amplitude.
文摘Soy protein isolate and egg white protein were added to cassava-banana gluten-free pasta and the effects on the nutritional quality,digestibility properties,protein digestibility corrected amino acid(PDCAA),and sensory acceptance of the pasta was observed.Banana-cassava composite flour(75:25)was blended with soy protein isolate or egg white protein at the following rates:0,5,10,and 15 g/100 g flour.Cooked pasta samples were analysed for total phenolic content(TPC),antioxidant activity,amino acid profiles,protein content,starch digestibility,protein digestibility and protein digestibility corrected amino acid score(PDCAAS).Addition of both proteins decreased starch digestibility,increased protein digestibility,improved the balance of the amino acid profile,and PDCAAS whereas only soy protein isolate enhanced the TPC and antioxidant capacity of the banana-cassava pasta.An egg white protein-fortified banana-cassava pasta had better customer acceptance and purchase intent than soy protein isolate inclusion.
