Starch serves as a critical storage component,significantly influencing the grain yield and quality of maize(Zea mays L.).Understanding the genetic basis of natural variation in kernel starch content(SC)is essential f...Starch serves as a critical storage component,significantly influencing the grain yield and quality of maize(Zea mays L.).Understanding the genetic basis of natural variation in kernel starch content(SC)is essential for maize breeding to meet future demands.A genome-wide association study(GWAS)identified 84 and 96 loci associated with kernel SC across two years,overlapping with 185 candidate genes.The candidate gene Zm MYB71,encoding a MYB-related transcription factor,demonstrated the highest co-expression frequency with starch synthesis genes.Analysis revealed that Zm MYB71 functions as a nuclear located transcription repressor,and mutants exhibited increased kernel SC by over 2.32%,with minimal impact on amylose content or 100-grain weight.Sh1,Sh2,and GBSSI exhibited up-regulation in mutants by 1.56-,1.45-and 1.32-fold,respectively,aligning with RNA sequencing results;their promoter activities appear directly repressed by Zm MYB71 through the GATATC and TTAGGG motifs.Additionally,the Zm MYB71 elite haplotype Hap1 occurred in over 55%of the high-starch maize sub-populations Iowa Stiff Stalk Synthetic(BSSS)and Partner B(PB),but only in 7.14%of the low-starch sub-population Partner A(PA).Analysis of Hap1 haplotype frequencies across breeding stages revealed a significant increase to 40.28%in inbred groups released after 2010,compared to 28.57 and 27.94%in 1980 and 1990,and 2000,respectively.These findings enhance understanding of natural variation in maize kernel SC and establish Zm MYB71 as a negative regulator with potential applications in SC improvement.展开更多
[Objective] The aim was to explore effects of different curing techniques on starch contents of tobaccos from different growth parts and with varying maturity degrees in order to reduce starch content of Yunnan tobacc...[Objective] The aim was to explore effects of different curing techniques on starch contents of tobaccos from different growth parts and with varying maturity degrees in order to reduce starch content of Yunnan tobacco. [Method] Compar- isons were conducted on tobaccos from upper, middle and down parts （immature, premature, mature and excessive mature） by low temperature and low humidity cur- ing technique, moderate temperature and moderate humidity curing technique, mod- erate temperature and high humidity curing technique to measure starch contents before and after curing. [Result] The results showed starch content of tobacco was increasing upon growth part. Low temperature and low humidity curing technique has poor effects on reduction of starch content; moderate temperature and moderate humidity curing technique improves starch content; moderate temperature and high humidity curing technique dramatically reduces starch content of tobaccos. [Conclu- sion] With consideration of tobacco appearance, inner quality and characters, moder- ate temperature and moderate humidity curing technique is recommended for tobac- co production.展开更多
Sweetpotato （Ipomoea batatas （L.） Lam.） breeding is challenging due to its genetic complexity. In the present study, interval mapping （IM） and multiple quantitative trait locus （QTL） model （MQM） analysis wer...Sweetpotato （Ipomoea batatas （L.） Lam.） breeding is challenging due to its genetic complexity. In the present study, interval mapping （IM） and multiple quantitative trait locus （QTL） model （MQM） analysis were used to identify QTLs for starch content with a mapping population consisting of 202 F1 individuals of a cross between Xushu 18, a cultivar susceptible to stem nematodes, with high yield and moderate starch, and Xu 781, which is resistant to stem nematodes, has low yield and high starch content. Six QTLs for starch content were mapped on six linkage groups of the Xu 781 map, explaining 9.1-38.8% of the variation. Especially, one of them, DMFN 4, accounted for 38.8% of starch content variation, which is the QTL that explains the highest phenotypic variation detected to date in sweetpotato. All of the six QTLs had a positive effect on the variation of the starch content, which indicated the inheritance derived from the parent Xu 781. Two QTLs for starch content were detected on two linkage groups of the Xushu 18 map, explaining 14.3 and 16.1% of the variation, respectively. They had a negative effect on the variation, indicating the inheritance derived from Xu 781. Seven of eight QTLs were co-localized with a single marker. This is the first report on the development of QTLs co-localized with a single marker in sweetpotato. These QTLs and their co-localized markers may be used in marker-assisted breeding for the starch content of sweetpotato.展开更多
A glutathione S-transferase(GST)gene IbGSTL2 was cloned and characterized from sweetpotato.It harbored a variation associated with starch content in storage roots.Overexpression of IbGSTL2 increased starch content and...A glutathione S-transferase(GST)gene IbGSTL2 was cloned and characterized from sweetpotato.It harbored a variation associated with starch content in storage roots.Overexpression of IbGSTL2 increased starch content and amylopectin proportion,decreased gelatinization temperature,and improved degree of crystallinity in sweetpotato storage roots,while its RNA interference resulted in the opposite trends.IbGSTL2 physically interacted with IbcPGM,an enzyme of sucrose metabolism,and improve starch content and quality by regulating genes involved in starch biosynthesis.展开更多
Starch is the most important component in endosperm of sorghum grain.Usually,two types of starch are present:amylose(AM)and amylopectin(AP).The levels of AM and AP contents play a significant role in the appearance,st...Starch is the most important component in endosperm of sorghum grain.Usually,two types of starch are present:amylose(AM)and amylopectin(AP).The levels of AM and AP contents play a significant role in the appearance,structure,and quality of sorghum grains and in marketing applications.In the present study,a panel of 634 sorghum(Sorghum bicolor(L.)Moench)accessions were evaluated for starch,AM,and AP contents of grain,which included a mini core collection of 242 accessions from the International Crops Research Institute for the Semi-Arid Tropics(ICRISAT)in India,and 252 landraces and 140 cultivars from China.The average starch content was 67.64%and the average AM and AP contents were 20.19 and 79.81%,respectively.We developed a total of 260000 high-confidence single nucleotide polymorphism(SNP)markers in the panel of 634 accessions of S.bicolor using specific locus amplified fragment sequencing(SLAF-seq).We performed genome-wide association studies(GWAS)of starch,AM,and AM/AP of grain and SNP markers based on a mixed linear model(MLM).In total,70 significant association signals were detected for starch,AM,and AM/AP ratio of grain with P<4.452×10^-7,of which 10 SNPs were identified with significant starch,51 SNPs were associated with AM,and nine SNPs were associated with the AM/AP ratio.The Gene Ontology(GO)analysis identified 12 candidate genes at five QTLs associated with starch metabolism within the 200-kb intervals,located on chromosomes 1,5,6,and 9.Of these genes,Sobic.006G036500.1 encodes peptidyl-prolyl cis-trans-isomerase CYP38 responsible for hexose monophosphate shunt(HMS)and Sobic.009G071800 encodes 6-phospho-fructokinase(PFK),which is involved in the embden-meyerhof pathway(EMP).Kompetitive allele specific PCR(KASP)markers were developed to validate the GWAS results.The C allele is correlated with a high starch content,while the T allele is linked with a low level of starch content,and provides reliable haplotypes for MAS in sorghum quality improvement.展开更多
Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we dev...Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content.展开更多
In order to provide a scientific basis for the utilization of cassava alcohol fermentation mash and the high-yield and high-efficiency cultivation of cassava,compound microbial inoculum was inoculated into the cassava...In order to provide a scientific basis for the utilization of cassava alcohol fermentation mash and the high-yield and high-efficiency cultivation of cassava,compound microbial inoculum was inoculated into the cassava alcohol fermentation mash to prepare bacterial manure,which was then applied to two cassava varieties,Nanzhi 199 and SC 205 to explore the optimum application amount,application method and application concentration. The results showed that when the inoculation amount of the compound microbial inoculum was 2‰ of the mass of the mash,the requirements of industrial production of liquid bacterial manure and agricultural application can be met,saving costs. After the emergence of cassava seedlings,if they were drenched with the bacterial manure of cassava alcohol fermentation mash through roots once according to the amount of 67. 5 t/ha and irrigated with the bacterial manure once every 15 d under drought conditions,both the yield and quality of cassava can be improved significantly. The yield and starch content of Nanzhi 199 reached 26 196. 23 kg/ha and 30. 32%,36. 57% and4. 75 percentage points higher than those of CK. The yield and starch content of SC 205 reached 41 126. 06 kg/ha and 23. 74%,99. 25% and3. 19 percentage points higher than those of CK. Under the application modes of foliar spray,root irrigation and foliar spray + root irrigation,the fertilization effect was more obvious. When undiluted bacterial manure of cassava alcohol fermentation mash was applied according to the amount of 52. 5 t/( ha·time),the fertilization effect of the application mode of foliar spray + root irrigation was the best. The bacterial manure from cassava alcohol fermentation mash can be directly applied without dilution,and the fertilizer efficiency will be reduced significantly after dilution.展开更多
A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potentia...A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.展开更多
The sense and antisense fragments of the soluble starch synthase （SSII1） gene and the intron fragment of somatic embryogenesis receptor-like kinase （SERK1） gene were cloned from potato using PCR techniques. The RN...The sense and antisense fragments of the soluble starch synthase （SSII1） gene and the intron fragment of somatic embryogenesis receptor-like kinase （SERK1） gene were cloned from potato using PCR techniques. The RNAi plant expression vectors pBI-SSIII-RNAi and pBIC-SSIII-RNAi were constructed which containing fusion fragment of ＂sense fragment-intron-antisense fragment＂ driven by the constitutive expression promoter CaMV 35S and the tuber-specific expression promoter CIPP, respectively. The putative transgenic plants of potato cultivars Kexin-1 and Kexin-4 were obtained using Agrobacterium-mediated transformation method. PCR assay showed that the interference fragment of SSlll gene was integrated into potato genome. The RT-PCR analysis showed that the expression of SSlll gene was repressed apparently on the transcription level. Starch granules of the transgenic potato plants were different in morphology and became cracked in starch granule centre compared with the non-transgenic control plants. The amylose content of starch was increased by 2.68-29.05%, amylopectin to amylose ratio of starch had declined significantly, and the phosphorus content of the starch of the transgenic plants was reduced 9.94-58.36% compared with control plants. The results could provide certain foundation for improvement of potato starch quality.展开更多
Effect of microwave modification on tapioca starch at different moisture contents was studied with polarized light microscope. It was observed that loss of birefringence was initiated at hilum of granule. The polariza...Effect of microwave modification on tapioca starch at different moisture contents was studied with polarized light microscope. It was observed that loss of birefringence was initiated at hilum of granule. The polarization cross of most granules had become somewhat unclear, and reduction in clarity of the polarization cross was proportioned with the moisture contents of native starch as modification by microwave. When the moisture contents reached to 35.0%, the polarization cross of most granules was lost, and the critical point of native starch was 30% in microwave modification.展开更多
Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments alter flowering were studied using two rice varieties IR72 （indica） and Nipponbare （japon...Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments alter flowering were studied using two rice varieties IR72 （indica） and Nipponbare （japonica） as materials. Under shading treatments, the starch, amylose and sucrose contents decreased, while ADP-glucose pyrophosphorylase （ADPGPPase） activity only changed a little, soluble starch synthase activity and granule bound starch synthase activity decreased, soluble starch branching enzyme （SSBE, Q-enzyme） activity and granule bound starch branching enzyme （GBSBE, Q-enzyme） activity increased, and starch debranching enzyme （DBE, R-enzyme） activity varied with varieties. Correlation analyses showed that the changes of starch content were positively and significantly correlated with the changes of sucrose content in the weak light. Both ADPGPPase activity and SSBE activity were positively and significantly correlated with starch accumulation rate. It was implied that the decline of starch synthase activities was related to the decrease of starch content and the increase of the activity of starch branching enzyme played an important role in the decrease of the ratio of amylose to the total starch under the weak light.展开更多
The property of starch in rice grain endosperm is a very important determinant for rice quality, and it is essential to understand the genetic effect of the genes related to starch synthesis in high-yielding rice vari...The property of starch in rice grain endosperm is a very important determinant for rice quality, and it is essential to understand the genetic effect of the genes related to starch synthesis in high-yielding rice varieties for rice quality improvement. The physicochemical properties （e.g., amylose content, gel consistency, and RVA profile） were assessed on 53 rice varieties, including certain typical indica/japonica landraces and certain high-yielding modern varieties. And molecular markers for Sbel, Sbe3 developed on the basis of sequence diversities between the rice subspecies indica and japonica, together with PCR-Acc I marker for Wx gene were used to investigate the genotypes of 53 rice cultivars. The result showed that the developed molecular markers for Wx, Sbel, Sbe3 could distinguish indica or japonica alleles at three loci. Among all the 53 rice cultivars, six genotypes were observed when Sbel, Sbe3, and Wx loci were considered together, while the genotypes of WxiSbelJSbe3i and WxiSbelJSbe3J were absent. In order to explore the genetic effects of the three genes, especially for starch branching enzyme genes, ANOVA and multiple comparison analysis were conducted. The results showed that rice cultivars with different genotypes exhibited different phenotypes, including amylose content, gel consistency and certain RVA characteristics, and the significant differences among the six genotypes were observed. It was concluded that these three genes had randomly recombined during the process of the rice variety development. And the genetic effects of indica and japonica alleles at three gene loci were different, of which, Wx gene plays a major role in determining the starch properties, followed by Sbel and Sbe3, and the genetic effects of Sbel and Sbe3 in different backgrounds （Wx~, WxJ） are different. The results have provided a clue for rice good quality variety development, and the molecular markers will benefit to the improvement in quality of rice.展开更多
There are nearly 1 000 rice landrace varieties in the Taihu basin, China. To assess the genetic diversity of the rice, 24 intragenic molecular markers（representing 17 starch synthesis-related genes） were investigate...There are nearly 1 000 rice landrace varieties in the Taihu basin, China. To assess the genetic diversity of the rice, 24 intragenic molecular markers（representing 17 starch synthesis-related genes） were investigated in 115 Taihu basin rice landraces and 87 improved cultivars simultaneously. The results show that the average genetic diversity and polymorphism information content values of the landraces were higher than those of improved cultivars. In total, 41 and 39 allele combinations（of the 17 genes） were derived from the landraces and improved cultivars, respectively; only two identical allele combinations were found bet ween the two rice variety sources. Cluster analysis, based on the molecular markers, revealed that the rice varieties could be subdivided into five groups and, within these, the japonica improved rice and japonica landrace rice varieties were in two separate groups. According to the quality reference criteria to classify the rice into grades, some of the landraces were found to perform we ll, in terms of starch quality. For example, according to NY /T595-2002 criteria from the Ministry of Agriculture of China, 25 and 33 landraces reached grade 1, in terms of their apparent amylose content and gel consistency. Th e varieties that had outstanding quality could be used as breeding materials for rice quality breeding programs in the future. Our study is useful for future applications, such as genetic diversity studies, the protection of rice variety and improvment of rice quality in breeding programs.展开更多
Three kinds of soil texture （clay-loam, mid-loam, and sand-loam soil） were used to study the effects of soil texture on starch accumulating rate and the changes in activities of the key enzymes of starch synthesis i...Three kinds of soil texture （clay-loam, mid-loam, and sand-loam soil） were used to study the effects of soil texture on starch accumulating rate and the changes in activities of the key enzymes of starch synthesis in the kernel during grain filling in high gluten content wheat ZM 9023, under conditions of pond culture. The content of starch and its components were measured according to the method of double-wave length described by Bao （1996）. ADP-glucose pyrophosphorylase （AGPP） activity was tested according to the method described by Doehlert et al. （1988）. Soluble starch synthase （SSS） and starch branching enzyme （SBE） activities were tested according to the method described by Nakamura et al. （1989）. The amylose, amylopectin, and total starch accumulating rate in the kernel of ZM 9023 were found to be a single-peak curve in three different soil textures during grain filling, and peaked 20, 15, and 15 d after anthesis, respectively. The activities of the enzymes, AGPP, SSS, and SBE, in the kernel of ZM 9023 had a single-peaked curve, which peaked 20, 15, and 15 d after anthesis, respectively. The activities of the above three enzymes of ZM 9023 were higher in the sand-loam soil. The accumulating peak of amylose formed later compared to that of amylopectin. The sand-loam soil could help high gluten content cultivars to synthesize starch.展开更多
Starch granules isolated from different accessions of rice from North East India showed a typical polygonal morphology with size ranging from 3.4 ± 0.8 μm to 6.4 ± 1.2 μm. The apparent amylose content (AAC...Starch granules isolated from different accessions of rice from North East India showed a typical polygonal morphology with size ranging from 3.4 ± 0.8 μm to 6.4 ± 1.2 μm. The apparent amylose content (AAC) of the granules varied from 1.9% to 28.33%. Our results identify starch from IC-583088 as “waxy” and IC-583085, IC-583038, DPRR-168 as “very low” amylo-. The coefficient of resistance to flow (n) for starch pastes from the varieties of rice studied in the present investigation recorded a value of <1.0. The observed “n” value deviates from the Newtonian flow indicating the pseudoplastic nature of starches isolated from these varieties. While starch pastes from the accession IC-583088 recorded the highest ‘‘n’’ value of 0.6, that from the accession IC-545197 showed the lowest value of 0.03. The variations in coefficient of resistance to flow clearly revealed a higher ‘‘n’’ value for starch pastes from the “waxy” and ‘‘low” amylo-cultivars than the “intermediate” or ‘‘high” amylo-cultivars. Our results clearly established characteristic rheological properties for starches from the accessions SKY-AK-1608, IC-583035, YS-RC-219, IC-564939 and IC-332963, which exhibited greater resistance to thinning and shearing than other varieties.展开更多
为明确适当减磷对马铃薯淀粉合成和产量的影响,于2018—2019年在宁夏半干旱地区海原县进行单因素随机区组设计,以当地农民习惯施磷量240 kg hm^(-2)(RP)为相对对照,设置4个减磷处理:P25(180 kg hm^(-2),减少25%)、P50(120 kg hm^(-2),减...为明确适当减磷对马铃薯淀粉合成和产量的影响,于2018—2019年在宁夏半干旱地区海原县进行单因素随机区组设计,以当地农民习惯施磷量240 kg hm^(-2)(RP)为相对对照,设置4个减磷处理:P25(180 kg hm^(-2),减少25%)、P50(120 kg hm^(-2),减少50%)、P75(60 kg hm^(-2),减少75%)、CK(0 kg hm^(-2),不施磷肥作为绝对对照),通过分析淀粉积累、相关酶活性及产量的关系,为该区域马铃薯可持续生产提供技术支撑。结果表明,适当降低施磷量可以显著提高马铃薯淀粉含量,加快积累速度,从而提高总产量。其中P50较RP支链淀粉和总淀粉含量分别增加7.64%和7.76%,淀粉积累速率最大时的积累量(W_(max))、淀粉最大积累速率(G_(max))和淀粉平均积累速率(G_(mean))分别增加8.92%、29.90%和26.23%,马铃薯淀粉产量、总干物质质量及总产量分别增加53.39%、50.92%和25.62%;腺苷二磷酸葡萄糖焦磷酸化酶(AGP)、尿苷二磷酸葡萄糖焦磷酸化酶(UGP)、可溶性淀粉合成酶(SSS)、颗粒型淀粉合成酶(GBSS)和淀粉分支酶(SBE)活性则分别提高29.74%、26.88%、31.42%、33.56%和18.72%。主成分分析表明,2年各处理综合得分均表现为P50>P25>RP>P75>CK。马铃薯减磷50%(施磷量为120 kg hm^(-2))对其块茎淀粉合成关键酶活性、支链淀粉、直链淀粉和总淀粉含量均有显著提升作用,对各阶段各淀粉组成的积累速率有显著改善效果并能持续优化总淀粉的积累特性,进而提高淀粉产量、总干物质积累量及总产量,综合分析得出,在宁夏半干旱区推荐马铃薯最佳经济施磷范围为120~137 kg hm^(-2),从而达到绿色高产栽培的目的。展开更多
为探究氮素对粳米食味品质、营养品质和精碾磨粉特性的影响,以不同食味粳稻品种沈农9816、秋田小町、北粳3号和盐粳476为试验材料,设置0 kg hm^(-2) (N0)、50 kg hm^(-2) (N1)、100 kg hm^(-2) (N2)和200 kg hm^(-2) (N3)4个氮素水平,...为探究氮素对粳米食味品质、营养品质和精碾磨粉特性的影响,以不同食味粳稻品种沈农9816、秋田小町、北粳3号和盐粳476为试验材料,设置0 kg hm^(-2) (N0)、50 kg hm^(-2) (N1)、100 kg hm^(-2) (N2)和200 kg hm^(-2) (N3)4个氮素水平,研究了氮素水平对不同食味稻米品质与精碾磨粉颗粒形态特征的影响及其相互关系。结果表明:(1)稻米食味值表现为秋田小町>盐粳476>北粳3号>沈农9816,在不同氮素水平下表现一致。(2)随着氮素水平的提高,除秋田小町外,不同粳稻品种的食味品质(蒸煮食味值、外观、黏度、胶稠度)、支链淀粉A链、B1链含量均显著降低,硬度、直链淀粉含量和蛋白组分含量显著提高;峰值黏度、热浆黏度、最终黏度呈降低趋势,崩解值、消减值、糊化温度受氮素影响较小;精碾磨粉表面由光滑变为粗糙,颗粒粒径变大、数量增多呈堆积状,并伴随裂痕和空隙现象发生。(3)相关分析表明,氮素水平与与蒸煮食味品质(黏度、外观和食味值)、RVA特征值谱(峰值黏度、热浆黏度、最终黏度)均呈极显著负相关,但与硬度及精碾磨粉表面颗粒粒径呈极显著正相关;精碾磨粉表面颗粒粒径与蒸煮食味品质(食味值、外观)、RVA特征值谱(黏度、峰值黏度、热浆黏度及最终黏度)呈极显著负相关,但与硬度呈显著正相关。综合来看,食味值高的品种对氮素响应较弱,且精碾磨粉表面特性稳定,进而保证了其食味品质的稳定性。展开更多
基金the financial support from the National Key Research and Development Program of China(2021YFD1201004)the Science and Technology Innovation Project,Chinese Academy of Agricultural Sciences(CAAS-ZDRW202201)the Shandong Provincial Key R&D Program,China(2023LZGC010)。
文摘Starch serves as a critical storage component,significantly influencing the grain yield and quality of maize(Zea mays L.).Understanding the genetic basis of natural variation in kernel starch content(SC)is essential for maize breeding to meet future demands.A genome-wide association study(GWAS)identified 84 and 96 loci associated with kernel SC across two years,overlapping with 185 candidate genes.The candidate gene Zm MYB71,encoding a MYB-related transcription factor,demonstrated the highest co-expression frequency with starch synthesis genes.Analysis revealed that Zm MYB71 functions as a nuclear located transcription repressor,and mutants exhibited increased kernel SC by over 2.32%,with minimal impact on amylose content or 100-grain weight.Sh1,Sh2,and GBSSI exhibited up-regulation in mutants by 1.56-,1.45-and 1.32-fold,respectively,aligning with RNA sequencing results;their promoter activities appear directly repressed by Zm MYB71 through the GATATC and TTAGGG motifs.Additionally,the Zm MYB71 elite haplotype Hap1 occurred in over 55%of the high-starch maize sub-populations Iowa Stiff Stalk Synthetic(BSSS)and Partner B(PB),but only in 7.14%of the low-starch sub-population Partner A(PA).Analysis of Hap1 haplotype frequencies across breeding stages revealed a significant increase to 40.28%in inbred groups released after 2010,compared to 28.57 and 27.94%in 1980 and 1990,and 2000,respectively.These findings enhance understanding of natural variation in maize kernel SC and establish Zm MYB71 as a negative regulator with potential applications in SC improvement.
基金Supported by China National Tobacco Corporation S&T Project(〔2012〕122)Chongqing Branch Company S&T Project of China National Tobacco Corporation(NY20110601070010)~~
文摘[Objective] The aim was to explore effects of different curing techniques on starch contents of tobaccos from different growth parts and with varying maturity degrees in order to reduce starch content of Yunnan tobacco. [Method] Compar- isons were conducted on tobaccos from upper, middle and down parts （immature, premature, mature and excessive mature） by low temperature and low humidity cur- ing technique, moderate temperature and moderate humidity curing technique, mod- erate temperature and high humidity curing technique to measure starch contents before and after curing. [Result] The results showed starch content of tobacco was increasing upon growth part. Low temperature and low humidity curing technique has poor effects on reduction of starch content; moderate temperature and moderate humidity curing technique improves starch content; moderate temperature and high humidity curing technique dramatically reduces starch content of tobaccos. [Conclu- sion] With consideration of tobacco appearance, inner quality and characters, moder- ate temperature and moderate humidity curing technique is recommended for tobac- co production.
基金supported by the China Agriculture Research System(CARS-11,Sweetpotato)the National High-Tech R&D Program of China(2012AA101204)
文摘Sweetpotato （Ipomoea batatas （L.） Lam.） breeding is challenging due to its genetic complexity. In the present study, interval mapping （IM） and multiple quantitative trait locus （QTL） model （MQM） analysis were used to identify QTLs for starch content with a mapping population consisting of 202 F1 individuals of a cross between Xushu 18, a cultivar susceptible to stem nematodes, with high yield and moderate starch, and Xu 781, which is resistant to stem nematodes, has low yield and high starch content. Six QTLs for starch content were mapped on six linkage groups of the Xu 781 map, explaining 9.1-38.8% of the variation. Especially, one of them, DMFN 4, accounted for 38.8% of starch content variation, which is the QTL that explains the highest phenotypic variation detected to date in sweetpotato. All of the six QTLs had a positive effect on the variation of the starch content, which indicated the inheritance derived from the parent Xu 781. Two QTLs for starch content were detected on two linkage groups of the Xushu 18 map, explaining 14.3 and 16.1% of the variation, respectively. They had a negative effect on the variation, indicating the inheritance derived from Xu 781. Seven of eight QTLs were co-localized with a single marker. This is the first report on the development of QTLs co-localized with a single marker in sweetpotato. These QTLs and their co-localized markers may be used in marker-assisted breeding for the starch content of sweetpotato.
基金supported by the National Key Research and Development Program of China (2023YFD1200701/2023YFD1200700)the Earmarked Fund for CARS-10-Sweetpotato.
文摘A glutathione S-transferase(GST)gene IbGSTL2 was cloned and characterized from sweetpotato.It harbored a variation associated with starch content in storage roots.Overexpression of IbGSTL2 increased starch content and amylopectin proportion,decreased gelatinization temperature,and improved degree of crystallinity in sweetpotato storage roots,while its RNA interference resulted in the opposite trends.IbGSTL2 physically interacted with IbcPGM,an enzyme of sucrose metabolism,and improve starch content and quality by regulating genes involved in starch biosynthesis.
基金supported by the earmarked fund for China Agriculture Research System (CARS-06)
文摘Starch is the most important component in endosperm of sorghum grain.Usually,two types of starch are present:amylose(AM)and amylopectin(AP).The levels of AM and AP contents play a significant role in the appearance,structure,and quality of sorghum grains and in marketing applications.In the present study,a panel of 634 sorghum(Sorghum bicolor(L.)Moench)accessions were evaluated for starch,AM,and AP contents of grain,which included a mini core collection of 242 accessions from the International Crops Research Institute for the Semi-Arid Tropics(ICRISAT)in India,and 252 landraces and 140 cultivars from China.The average starch content was 67.64%and the average AM and AP contents were 20.19 and 79.81%,respectively.We developed a total of 260000 high-confidence single nucleotide polymorphism(SNP)markers in the panel of 634 accessions of S.bicolor using specific locus amplified fragment sequencing(SLAF-seq).We performed genome-wide association studies(GWAS)of starch,AM,and AM/AP of grain and SNP markers based on a mixed linear model(MLM).In total,70 significant association signals were detected for starch,AM,and AM/AP ratio of grain with P<4.452×10^-7,of which 10 SNPs were identified with significant starch,51 SNPs were associated with AM,and nine SNPs were associated with the AM/AP ratio.The Gene Ontology(GO)analysis identified 12 candidate genes at five QTLs associated with starch metabolism within the 200-kb intervals,located on chromosomes 1,5,6,and 9.Of these genes,Sobic.006G036500.1 encodes peptidyl-prolyl cis-trans-isomerase CYP38 responsible for hexose monophosphate shunt(HMS)and Sobic.009G071800 encodes 6-phospho-fructokinase(PFK),which is involved in the embden-meyerhof pathway(EMP).Kompetitive allele specific PCR(KASP)markers were developed to validate the GWAS results.The C allele is correlated with a high starch content,while the T allele is linked with a low level of starch content,and provides reliable haplotypes for MAS in sorghum quality improvement.
基金supported by Earmarked Fund for China Agriculture Research System(CARS-09-P07)the National Natural Science Foundation of China(31160299,31760410)
文摘Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content.
基金Supported by Guangxi Science and Technology Plan Project(Gui Ke AA16380013)Scientific Research and Technological Development Program of Guangxi(20162106)
文摘In order to provide a scientific basis for the utilization of cassava alcohol fermentation mash and the high-yield and high-efficiency cultivation of cassava,compound microbial inoculum was inoculated into the cassava alcohol fermentation mash to prepare bacterial manure,which was then applied to two cassava varieties,Nanzhi 199 and SC 205 to explore the optimum application amount,application method and application concentration. The results showed that when the inoculation amount of the compound microbial inoculum was 2‰ of the mass of the mash,the requirements of industrial production of liquid bacterial manure and agricultural application can be met,saving costs. After the emergence of cassava seedlings,if they were drenched with the bacterial manure of cassava alcohol fermentation mash through roots once according to the amount of 67. 5 t/ha and irrigated with the bacterial manure once every 15 d under drought conditions,both the yield and quality of cassava can be improved significantly. The yield and starch content of Nanzhi 199 reached 26 196. 23 kg/ha and 30. 32%,36. 57% and4. 75 percentage points higher than those of CK. The yield and starch content of SC 205 reached 41 126. 06 kg/ha and 23. 74%,99. 25% and3. 19 percentage points higher than those of CK. Under the application modes of foliar spray,root irrigation and foliar spray + root irrigation,the fertilization effect was more obvious. When undiluted bacterial manure of cassava alcohol fermentation mash was applied according to the amount of 52. 5 t/( ha·time),the fertilization effect of the application mode of foliar spray + root irrigation was the best. The bacterial manure from cassava alcohol fermentation mash can be directly applied without dilution,and the fertilizer efficiency will be reduced significantly after dilution.
基金supported by the National Natural Science Foundation of China(31371680)the Beijing Food Crops Innovation Consortium Programthe China Agriculture Research System(CARS-11)
文摘A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.
基金supported by the National High-Technology R&D Program of China(2006AA100107)the National Natural Science Foundation of China(30871573, 31160298)
文摘The sense and antisense fragments of the soluble starch synthase （SSII1） gene and the intron fragment of somatic embryogenesis receptor-like kinase （SERK1） gene were cloned from potato using PCR techniques. The RNAi plant expression vectors pBI-SSIII-RNAi and pBIC-SSIII-RNAi were constructed which containing fusion fragment of ＂sense fragment-intron-antisense fragment＂ driven by the constitutive expression promoter CaMV 35S and the tuber-specific expression promoter CIPP, respectively. The putative transgenic plants of potato cultivars Kexin-1 and Kexin-4 were obtained using Agrobacterium-mediated transformation method. PCR assay showed that the interference fragment of SSlll gene was integrated into potato genome. The RT-PCR analysis showed that the expression of SSlll gene was repressed apparently on the transcription level. Starch granules of the transgenic potato plants were different in morphology and became cracked in starch granule centre compared with the non-transgenic control plants. The amylose content of starch was increased by 2.68-29.05%, amylopectin to amylose ratio of starch had declined significantly, and the phosphorus content of the starch of the transgenic plants was reduced 9.94-58.36% compared with control plants. The results could provide certain foundation for improvement of potato starch quality.
文摘Effect of microwave modification on tapioca starch at different moisture contents was studied with polarized light microscope. It was observed that loss of birefringence was initiated at hilum of granule. The polarization cross of most granules had become somewhat unclear, and reduction in clarity of the polarization cross was proportioned with the moisture contents of native starch as modification by microwave. When the moisture contents reached to 35.0%, the polarization cross of most granules was lost, and the critical point of native starch was 30% in microwave modification.
文摘Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments alter flowering were studied using two rice varieties IR72 （indica） and Nipponbare （japonica） as materials. Under shading treatments, the starch, amylose and sucrose contents decreased, while ADP-glucose pyrophosphorylase （ADPGPPase） activity only changed a little, soluble starch synthase activity and granule bound starch synthase activity decreased, soluble starch branching enzyme （SSBE, Q-enzyme） activity and granule bound starch branching enzyme （GBSBE, Q-enzyme） activity increased, and starch debranching enzyme （DBE, R-enzyme） activity varied with varieties. Correlation analyses showed that the changes of starch content were positively and significantly correlated with the changes of sucrose content in the weak light. Both ADPGPPase activity and SSBE activity were positively and significantly correlated with starch accumulation rate. It was implied that the decline of starch synthase activities was related to the decrease of starch content and the increase of the activity of starch branching enzyme played an important role in the decrease of the ratio of amylose to the total starch under the weak light.
基金This work was financially supported by the National Natural Science Foundation of China （30270809, 30300220 and 30530470）National 973 Project of China （2005CB 120804）.
文摘The property of starch in rice grain endosperm is a very important determinant for rice quality, and it is essential to understand the genetic effect of the genes related to starch synthesis in high-yielding rice varieties for rice quality improvement. The physicochemical properties （e.g., amylose content, gel consistency, and RVA profile） were assessed on 53 rice varieties, including certain typical indica/japonica landraces and certain high-yielding modern varieties. And molecular markers for Sbel, Sbe3 developed on the basis of sequence diversities between the rice subspecies indica and japonica, together with PCR-Acc I marker for Wx gene were used to investigate the genotypes of 53 rice cultivars. The result showed that the developed molecular markers for Wx, Sbel, Sbe3 could distinguish indica or japonica alleles at three loci. Among all the 53 rice cultivars, six genotypes were observed when Sbel, Sbe3, and Wx loci were considered together, while the genotypes of WxiSbelJSbe3i and WxiSbelJSbe3J were absent. In order to explore the genetic effects of the three genes, especially for starch branching enzyme genes, ANOVA and multiple comparison analysis were conducted. The results showed that rice cultivars with different genotypes exhibited different phenotypes, including amylose content, gel consistency and certain RVA characteristics, and the significant differences among the six genotypes were observed. It was concluded that these three genes had randomly recombined during the process of the rice variety development. And the genetic effects of indica and japonica alleles at three gene loci were different, of which, Wx gene plays a major role in determining the starch properties, followed by Sbel and Sbe3, and the genetic effects of Sbel and Sbe3 in different backgrounds （Wx~, WxJ） are different. The results have provided a clue for rice good quality variety development, and the molecular markers will benefit to the improvement in quality of rice.
基金financially supported by the National Natural Science Foundation of China(30800603)the Science and Technology Plan Projects of Taicang City,China(TC214YY3)the Building Program of the Science and Technology Innovation Team of Chien-Shiung Institute of Technology,China(2013CX02)
文摘There are nearly 1 000 rice landrace varieties in the Taihu basin, China. To assess the genetic diversity of the rice, 24 intragenic molecular markers（representing 17 starch synthesis-related genes） were investigated in 115 Taihu basin rice landraces and 87 improved cultivars simultaneously. The results show that the average genetic diversity and polymorphism information content values of the landraces were higher than those of improved cultivars. In total, 41 and 39 allele combinations（of the 17 genes） were derived from the landraces and improved cultivars, respectively; only two identical allele combinations were found bet ween the two rice variety sources. Cluster analysis, based on the molecular markers, revealed that the rice varieties could be subdivided into five groups and, within these, the japonica improved rice and japonica landrace rice varieties were in two separate groups. According to the quality reference criteria to classify the rice into grades, some of the landraces were found to perform we ll, in terms of starch quality. For example, according to NY /T595-2002 criteria from the Ministry of Agriculture of China, 25 and 33 landraces reached grade 1, in terms of their apparent amylose content and gel consistency. Th e varieties that had outstanding quality could be used as breeding materials for rice quality breeding programs in the future. Our study is useful for future applications, such as genetic diversity studies, the protection of rice variety and improvment of rice quality in breeding programs.
文摘Three kinds of soil texture （clay-loam, mid-loam, and sand-loam soil） were used to study the effects of soil texture on starch accumulating rate and the changes in activities of the key enzymes of starch synthesis in the kernel during grain filling in high gluten content wheat ZM 9023, under conditions of pond culture. The content of starch and its components were measured according to the method of double-wave length described by Bao （1996）. ADP-glucose pyrophosphorylase （AGPP） activity was tested according to the method described by Doehlert et al. （1988）. Soluble starch synthase （SSS） and starch branching enzyme （SBE） activities were tested according to the method described by Nakamura et al. （1989）. The amylose, amylopectin, and total starch accumulating rate in the kernel of ZM 9023 were found to be a single-peak curve in three different soil textures during grain filling, and peaked 20, 15, and 15 d after anthesis, respectively. The activities of the enzymes, AGPP, SSS, and SBE, in the kernel of ZM 9023 had a single-peaked curve, which peaked 20, 15, and 15 d after anthesis, respectively. The activities of the above three enzymes of ZM 9023 were higher in the sand-loam soil. The accumulating peak of amylose formed later compared to that of amylopectin. The sand-loam soil could help high gluten content cultivars to synthesize starch.
文摘Starch granules isolated from different accessions of rice from North East India showed a typical polygonal morphology with size ranging from 3.4 ± 0.8 μm to 6.4 ± 1.2 μm. The apparent amylose content (AAC) of the granules varied from 1.9% to 28.33%. Our results identify starch from IC-583088 as “waxy” and IC-583085, IC-583038, DPRR-168 as “very low” amylo-. The coefficient of resistance to flow (n) for starch pastes from the varieties of rice studied in the present investigation recorded a value of <1.0. The observed “n” value deviates from the Newtonian flow indicating the pseudoplastic nature of starches isolated from these varieties. While starch pastes from the accession IC-583088 recorded the highest ‘‘n’’ value of 0.6, that from the accession IC-545197 showed the lowest value of 0.03. The variations in coefficient of resistance to flow clearly revealed a higher ‘‘n’’ value for starch pastes from the “waxy” and ‘‘low” amylo-cultivars than the “intermediate” or ‘‘high” amylo-cultivars. Our results clearly established characteristic rheological properties for starches from the accessions SKY-AK-1608, IC-583035, YS-RC-219, IC-564939 and IC-332963, which exhibited greater resistance to thinning and shearing than other varieties.
文摘为明确适当减磷对马铃薯淀粉合成和产量的影响,于2018—2019年在宁夏半干旱地区海原县进行单因素随机区组设计,以当地农民习惯施磷量240 kg hm^(-2)(RP)为相对对照,设置4个减磷处理:P25(180 kg hm^(-2),减少25%)、P50(120 kg hm^(-2),减少50%)、P75(60 kg hm^(-2),减少75%)、CK(0 kg hm^(-2),不施磷肥作为绝对对照),通过分析淀粉积累、相关酶活性及产量的关系,为该区域马铃薯可持续生产提供技术支撑。结果表明,适当降低施磷量可以显著提高马铃薯淀粉含量,加快积累速度,从而提高总产量。其中P50较RP支链淀粉和总淀粉含量分别增加7.64%和7.76%,淀粉积累速率最大时的积累量(W_(max))、淀粉最大积累速率(G_(max))和淀粉平均积累速率(G_(mean))分别增加8.92%、29.90%和26.23%,马铃薯淀粉产量、总干物质质量及总产量分别增加53.39%、50.92%和25.62%;腺苷二磷酸葡萄糖焦磷酸化酶(AGP)、尿苷二磷酸葡萄糖焦磷酸化酶(UGP)、可溶性淀粉合成酶(SSS)、颗粒型淀粉合成酶(GBSS)和淀粉分支酶(SBE)活性则分别提高29.74%、26.88%、31.42%、33.56%和18.72%。主成分分析表明,2年各处理综合得分均表现为P50>P25>RP>P75>CK。马铃薯减磷50%(施磷量为120 kg hm^(-2))对其块茎淀粉合成关键酶活性、支链淀粉、直链淀粉和总淀粉含量均有显著提升作用,对各阶段各淀粉组成的积累速率有显著改善效果并能持续优化总淀粉的积累特性,进而提高淀粉产量、总干物质积累量及总产量,综合分析得出,在宁夏半干旱区推荐马铃薯最佳经济施磷范围为120~137 kg hm^(-2),从而达到绿色高产栽培的目的。
文摘为探究氮素对粳米食味品质、营养品质和精碾磨粉特性的影响,以不同食味粳稻品种沈农9816、秋田小町、北粳3号和盐粳476为试验材料,设置0 kg hm^(-2) (N0)、50 kg hm^(-2) (N1)、100 kg hm^(-2) (N2)和200 kg hm^(-2) (N3)4个氮素水平,研究了氮素水平对不同食味稻米品质与精碾磨粉颗粒形态特征的影响及其相互关系。结果表明:(1)稻米食味值表现为秋田小町>盐粳476>北粳3号>沈农9816,在不同氮素水平下表现一致。(2)随着氮素水平的提高,除秋田小町外,不同粳稻品种的食味品质(蒸煮食味值、外观、黏度、胶稠度)、支链淀粉A链、B1链含量均显著降低,硬度、直链淀粉含量和蛋白组分含量显著提高;峰值黏度、热浆黏度、最终黏度呈降低趋势,崩解值、消减值、糊化温度受氮素影响较小;精碾磨粉表面由光滑变为粗糙,颗粒粒径变大、数量增多呈堆积状,并伴随裂痕和空隙现象发生。(3)相关分析表明,氮素水平与与蒸煮食味品质(黏度、外观和食味值)、RVA特征值谱(峰值黏度、热浆黏度、最终黏度)均呈极显著负相关,但与硬度及精碾磨粉表面颗粒粒径呈极显著正相关;精碾磨粉表面颗粒粒径与蒸煮食味品质(食味值、外观)、RVA特征值谱(黏度、峰值黏度、热浆黏度及最终黏度)呈极显著负相关,但与硬度呈显著正相关。综合来看,食味值高的品种对氮素响应较弱,且精碾磨粉表面特性稳定,进而保证了其食味品质的稳定性。
