Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of cor...Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of corn leaf as the reaction time increased. On the contrary, the pH of corn leaf hydrolysate increased more than that of corn stalk with diluted acid addition. Increasing temperature enhanced the xylose dissolution rate and increased cellulose digestibility. Compared with hot water, 0.1% sulfuric acid addition improved the xylan removal and the enzymatic hydrolysis of both corn leaf and corn stalk residue. Much less xylan must be removed to achieve the same cellulose digestibility for the corn leaf as that for the corn stalk; 55% digestibility was obtained when only 32% xylan was removed from corn leaf, whereas corn stalk required removal of about 50% of the xylan to achieve the same di- gestibility. Overall, the descending order of enzymatic digestibility was: dilute acid hydrolysate of corn leaf > dilute acid hydrolysate of corn stalk > water-only hydrolysate of corn leaf > water-only hydrolysate of corn stalk. Finally, one separate pretreatment strategy was developed to transfer corn leaf and corn stalk to fermentable sugars for fur- ther bioenergy production.展开更多
Maize(Zea mays L.), also known as corn, is the third most cultivated crop in the world. Northern corn leaf blight(NCLB) is a globally devastating maize foliar disease caused by Setosphaeria turcica(Luttrell) Leonard a...Maize(Zea mays L.), also known as corn, is the third most cultivated crop in the world. Northern corn leaf blight(NCLB) is a globally devastating maize foliar disease caused by Setosphaeria turcica(Luttrell) Leonard and Suggs. Early intelligent diagnosis and warning is an effective and economical strategy to control this disease. Today, deep learning is beginning to play an essential role in agriculture. Notably, deep convolutional neural networks(DCNN) are amongst the most successful machine learning techniques in plant disease detection and diagnosis. Our study aims to identify NCLB in the maize-producing area in Jilin Province based on several DCNN models. We established a database of 985 leaf images of healthy and infected maize and applied data augmentation techniques including image segmentation, image resizing, image cropping, and image transformation, to expand to 30 655 images. Several proven convolutional neural networks, such as AlexNet, Google Net, VGG16, and VGG19, were then used to identify diseases. Based on the best performance of the DCNN pre-trained model Google Net, some of the recent loss functions developed for deep facial recognition tasks such as Arc Face, Cos Face, and A-Softmax were applied to detect NCLB. We found that a pre-trained Google Net architecture with the Softmax loss function can achieve an excellent accuracy of 99.94% on NCLB diagnosis. The analysis was implemented in Python with two deep learning frameworks, Pytorch and Keras. The techniques, training, validation, and test results are presented in this paper. Overall, our study explores intelligent identification technology for NCLB and effectively diagnoses NCLB from images of maize.展开更多
Maize is cultivated extensively throughout the world and has the highest production among cereals.However,Northern corn leaf blight(NCLB)disease caused by Exherohilum turcicum,is the most devastating limiting factor o...Maize is cultivated extensively throughout the world and has the highest production among cereals.However,Northern corn leaf blight(NCLB)disease caused by Exherohilum turcicum,is the most devastating limiting factor of maize production.The disease causes immense losses to corn yield if it develops prior or during the tasseling and silking stages of crop development.It has a worldwide distribution and its development is favoured by cool to moderate temperatures with high relative humidity.The prevalence of the disease has increased in recent years and new races of the pathogen have been reported worldwide.The fungus E.turcicum is highly variable in nature.Though different management strategies have proved effective to reduce economic losses from NCLB,the development of varieties with resistance to E.turcicum is the most efficient and inexpensive way for disease management.Qualitative resistance for NCLB governed by Ht genes is a race-specific resistance which leads to a higher level of resistance.However,some Ht genes can easily become ineffective under the high pressure of virulent strains of the pathogen.Hence,it is imperative to understand and examine the consistency of the genomic locations of quantitative trait loci for resistance to NCLB in diverse maize populations.The breeding approaches for pyramiding resistant genes against E.turcicum in maize can impart NCLB resistance under high disease pressure environments.Furthermore,the genome editing approaches like CRISPR-cas9 and RNAi can also prove vital for developing NCLB resistant maize cultivars.As such this review delivers emphasis on the importance and current status of the disease,racial spectrum of the pathogen,genetic nature and breeding approaches for resistance and management strategies of the disease in a sustainable manner.展开更多
Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of cor...Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of corn leaf as the reaction time increased. On the contrary, the pH of corn leaf hydrolysate increased more than that of corn stalk with diluted acid addition. Increasing temperature enhanced the xylose dissolution rate and increased cellulose digestibility. Compared with hot water, 0.1% sulfuric acid addition improved the xylan removal and the enzymatic hydrolysis of both corn leaf and corn stalk residue. Much less xylan must be removed to achieve the same cellulose digestibility for the corn leaf as that for the corn stalk; 55% digestibility was obtained when only 32% xylan was removed from corn leaf, whereas corn stalk required removal of about 50% of the xylan to achieve the same di- gestibility. Overall, the descending order of enzymatic digestibility was: dilute acid hydrolysate of corn leaf > dilute acid hydrolysate of corn stalk > water-only hydrolysate of corn leaf > water-only hydrolysate of corn stalk. Finally, one separate pretreatment strategy was developed to transfer corn leaf and corn stalk to fermentable sugars for fur- ther bioenergy production.展开更多
Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on c...Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season.展开更多
rhml is a major recessive disease resistance locus for Southern corn leaf blight （SCLB）. To further narrow down its genetic position, F2 population and BCIFI population derived from the cross between resistant （H95...rhml is a major recessive disease resistance locus for Southern corn leaf blight （SCLB）. To further narrow down its genetic position, F2 population and BCIFI population derived from the cross between resistant （H95rhm） and susceptible parents （H95） of maize （Zea mays） were constructed. Using newly developed markers, rhml was initially delimited within an interval of 2.5 Mb, and then finally mapped to a 8.56 kb interval between InDel marker IDP961-503 and simple sequence repeat （SSR） marker A194149--1. Three polymorphic markers IDP961-504, IDP B2-3 and A194149-2 were shown to be co-segregated with the rhml locus. Sequence analysis of the 8.56 kb DNA fragment revealed that it contained only one putative gene with a predicted amino acid sequence identical to lysine histidine transporter 1 （LHT1）. Comparative sequence analysis indicated that the LHT1 in H95rhrn harbors a 354 bp insertion in its third exon as compared with that of susceptible alleles in B73, H95 and Mo17. The 354 bp insertion resulted in a truncation of the predicted protein of candidate resistance allele （LHT1-H95rhm）. Our results strongly suggest LHTI as the candidate gene for rhml against SCLB. The tightly linked molecular markers developed in this study can be directly used for molecular breeding of resistance to Southern corn leaf blight in maize.展开更多
Southern corn leaf blight (SCLB), caused by Bipolarismaydis, is one of the most devastatingdiseases affecting maize production. However,only one SLCB resistance gene, conferring partialresistance, is currently known, ...Southern corn leaf blight (SCLB), caused by Bipolarismaydis, is one of the most devastatingdiseases affecting maize production. However,only one SLCB resistance gene, conferring partialresistance, is currently known, underscoring theimportance of isolating new SCLB resistancerelatedgenes. Here, we performed a comparativeproteomic analysis and identified 258 proteinsshowing differential abundance during the maizeresponse to B. maydis. These proteins included anascorbate peroxidase (Zea mays ascorbate peroxidase1 (ZmAPX1)) encoded by a gene locatedwithin the mapping interval of a previously identifiedquantitative trait locus associated with SCLBresistance. ZmAPX1 overexpression resulted inlower H_(2)O_(2) accumulation and enhanced resistanceagainst B. maydis. Jasmonic acid (JA)contents and transcript levels for JA biosynthesisand responsive genes increased in ZmAPX1-overexpressing plants infected with B. maydis,whereas Zmapx1 mutants showed the oppositeeffects. We further determined that low levels of H_(2)O_(2) are accompanied by an accumulation of JAthat enhances SCLB resistance. These resultsdemonstrate that ZmAPX1 positively regulatesSCLB resistance by decreasing H_(2)O_(2) accumulationand activating the JA-mediated defensesignaling pathway. This study identified ZmAPX1as a potentially useful gene for increasing SCLBresistance. Furthermore, the generated datamay be relevant for clarifying the functions ofplant APXs.展开更多
[ Objective] The paper was to evaluate the resistance of particular corn hybrids against northern leaf blight. [ Method ] Using artificial inoculation meth- od, the resistance of 238 copies of particular corn hybrids ...[ Objective] The paper was to evaluate the resistance of particular corn hybrids against northern leaf blight. [ Method ] Using artificial inoculation meth- od, the resistance of 238 copies of particular corn hybrids including silage corn, high oil corn, waxy corn and sweet corn against northern leaf blight was evaluated. [ Result] The corn samples with high resistance, resistance, moderate resistance, susceptibility and high susceptibility to northern leaf blight among 238 copies of materials in identification accounted for 0.8%, 20.6%, 44. 1%, 24.8% and 9.7%, respectively. Different types of varieties had significant difference in resist- ance. Among cern varieties with moderate resistance or higher level, silage corn accounted for 87.8% ; high oil corn and waxy corn accounted for 73.3% and 61.3 %, respectively; sweet corn was less, accounting for 44.2%. Sixteen of 30 approved particular corn varieties showed resistance, accounting for 53.3 % of total approved varieties. [Condusion] The paper provided theoretical basis for breeding and planting of particular corn hybrids with resistance against northern leaf blight.展开更多
The northem corn leaf blight is one of the most serious diseases in maize production. The research progress on etiology, generation law and control strategy, antigen identification, resistance mechanism and inheritanc...The northem corn leaf blight is one of the most serious diseases in maize production. The research progress on etiology, generation law and control strategy, antigen identification, resistance mechanism and inheritance of this disease was discussed. And the research work which should be enhanced in China was pointed out, such as mechanism of resistance inheritance, developing function marker, gene mining, screening resistance resource and dominant physiological race in different areas.展开更多
Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration w...Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration with early- to mid- season plant height of corn at Milan, TN from 2008 to 2010 using linear, quadratic, square root, logarithmic, and exponential models. Six N rate treatments (0, 62, 123, 185, 247, and 308 kg·N·ha-1) repeated four times were implemented each year in a randomized complete block design under four major cropping systems: corn after corn, corn after soybean [Glycine max (L.) Merr.], corn after cotton [Gossypium hirsutum (L.)], and irrigated corn after soybean. The relationship of ear leaf N concentration determined at the blister growth stage (R2) with plant height measured at the 6-leaf (V6), 10-leaf (V10), and 12-leaf (V12) growth stages was statistically significant and positive in non-irrigated corn under normal weather conditions. However, the strength of this relationship was weak to moderate with the determination coefficient (R2) values ranging from 0.21 to 0.51. This relationship was generally improved as the growing season progressed from V6 to V12. Irrigation and abnormal weather seemed to have adverse effects on this relationship. The five regression models performed similarly in the evaluation of this relationship regardless of growth stage, year, and cropping system. Our results suggest that unlike the relationship of corn yield at harvest with plant height measured during early- to mid-season or the relationship of leaf N concentration with plant height when both are measured simultaneously during early- to mid-season, the relationship of late-season ear leaf N concentration with early- to mid-season plant height may not be strong enough to be used to develop algorithms for variable-rate N applications on corn within a field no matter which regression model is used to describe this relationship.展开更多
Designing bio-inspired flow fields holds great potential in improving the performance of Proton Exchange Membrane Fuel Cell(PEMFC).Two kinds of biological prototypes are widely used:plant prototype and animal prototyp...Designing bio-inspired flow fields holds great potential in improving the performance of Proton Exchange Membrane Fuel Cell(PEMFC).Two kinds of biological prototypes are widely used:plant prototype and animal prototype.It remains a question which one of these prototypes is more appropriate for the scenario of PEMFC.Here,a comparative study was conducted to compare bionic flow fields based on animal and plant prototypes.First,a Corn Leaf Vein Mathematical Model(CLMM)was established by extracting structural parameters from corn leaves of two growth stages.Then the obtained CLMM and well-known Murray’s law were employed to design bionic flow fields corresponding to the plant and animal prototypes,respectively,which have been subsequently compared by numerical investigations.The results demonstrate that the flow field guided by Murray’s law outperforms the counterpart based on the structural parameters of CLMM in terms of PEMFC net output power,mass transport,water management and pressure drop,suggesting that animal circulation system is more suitable to the bionic flow field design of PEMFC than plant leaf veins.The work may also offer valuable insights into the design of other flow fields related to electrochemical energy conversion.展开更多
Fifteen field trials were conducted from 2009 to 2011 in Ontario, Canada and Michigan, USA to determine how long glyphosate-resistant corn needs to be kept weed-free after emergence to prevent yield loss. Data were se...Fifteen field trials were conducted from 2009 to 2011 in Ontario, Canada and Michigan, USA to determine how long glyphosate-resistant corn needs to be kept weed-free after emergence to prevent yield loss. Data were separated into two environments based on when yield loss first occurred after glyphosate application. In Environment 1 (4/15 sites) yield was not reduced when corn was kept weed-free until the 4-leaf stage. However, in Environment 2 (11/15 sites) there was no yield loss when corn was kept weed-free up to the 2-leaf stage. The most prominent weeds were velvetleaf, redroot pigweed, common ragweed, common lambsquarters and foxtail species. While later emerging weeds did not necessarily impact corn yield, weeds emerging after the 2- and 4-leaf corn stage likely produced seed that was added to the soil seed bank. Weeds emerging after 6-, 8-, and 10-leaf corn growth stages were small (low biomass/seedlings) and most likely did not reach reproductive maturity. Based on this research, corn must be maintained weed-free up to the 4-leaf stage. Any weeds emerging after that did not influence corn yield.展开更多
This study is aimed to explore the spectrum reflection characteristics of summer corn leaves in different fertilization conditions.Using hyperspectral remote sensing technology,the experiments were conducted in fields...This study is aimed to explore the spectrum reflection characteristics of summer corn leaves in different fertilization conditions.Using hyperspectral remote sensing technology,the experiments were conducted in fields to collect the hyperspectral images of Denghai 605( DH605) and Ludan 981( LD981) in different growth period under five fertilization treatments,and then the reflectance of corn ear leaves was extracted by ENVI software. The five fertilization treatments included the control( CK) with no fertilization,40 kg and 30 kg of controlled-release fertilizer per 666. 67 m2 as base( K40 and K30),50 kg and 40 kg of compound fertilizer per 666. 67 m2 as base with 15 kg urea as seed fertilizer( F50 + N and F40 + N). The reflectance spectrums of the two corn cultivars under different fertilization treatments showed the approximately same changing trend with a reflection peak at green band( 550 nm) and a higher reflection platform at near infrared band( 760 nm-1050 nm). At the heading to filling stage,the reflectance of DH605 and LD981 was the highest under the CK,followed by the K30 and F40 + N respectively. At the filling to dough stage,the reflectance of DH605 and LD981 was the highest under the treatment K30 and F40 + N respectively,which was obviously higher than that of the other treatments. In the conditions of compound fertilizer,except the late filling stage,LD981 had little higher reflectance than DH605 at the other stages. In the conditions of controlled-release fertilizer and at dough to mature stage,LD981 had obviously higher reflectance compared to the other stages,and also higher than that of DH605; there was not obvious difference in reflectance LD981 and DH605 at the other stages.展开更多
[目的]明确36%烯肟·氟环唑SC对玉米小斑病的防治效果。[方法]以17%唑醚·氟环唑SC和30%肟菌·戊唑醇SC为对照药剂,在山东省潍坊市寒亭区高里街道河南村玉米田进行田间小区试验。[结果]36%烯肟·氟环唑SC81、108 g a.i....[目的]明确36%烯肟·氟环唑SC对玉米小斑病的防治效果。[方法]以17%唑醚·氟环唑SC和30%肟菌·戊唑醇SC为对照药剂,在山东省潍坊市寒亭区高里街道河南村玉米田进行田间小区试验。[结果]36%烯肟·氟环唑SC81、108 g a.i./hm^(2)处理对玉米小斑病效果优于对照药剂17%唑醚·氟环唑SC和30%肟菌·戊唑醇SC,54 g a.i./hm^(2)的36%烯肟·氟环唑SC处理对玉米小斑病效果与对照药剂无显著性差异。[结论]使用36%烯肟·氟环唑SC54~108 g a.i./hm^(2)在玉米小斑病发病前或发病初期茎叶均匀喷雾,间隔7~10 d再施用1次,可有效防治玉米小斑病。展开更多
Corn, with C4 photosynthetic metabolism, often has no photosynthetic or yield response to elevated carbon dioxide concentrations. In C3 species, the yield stimulation at elevated carbon dioxide concentrations often de...Corn, with C4 photosynthetic metabolism, often has no photosynthetic or yield response to elevated carbon dioxide concentrations. In C3 species, the yield stimulation at elevated carbon dioxide concentrations often decreases with nitrogen limitation. I tested whether such a nitrogen interaction occurred in corn, by growing sweet corn in field plots in open top chambers at ambient and elevated (ambient + 180 mmol·mol-1) carbon dioxide concentrations for four seasons, with six nitrogen application rates, ranging from half to twice the locally recommended rate. At the recommended rate of nitrogen application, no carbon dioxide effect on production occurred. However, both ear and leaf plus stem biomass were lower for the elevated carbon dioxide treatment than for the ambient treatment at less than the recommended rate of nitrogen application, and higher at the highest rates of nitrogen application. There were no significant responses of mid-day leaf gas exchange rates to nitrogen application rate for either carbon dioxide treatment, and elevated carbon dioxide did not significantly increase leaf carbon dioxide assimilation rates at any nitrogen level. Leaf area index during vegetative growth increased more with nitrogen application rate at elevated than at ambient carbon dioxide. It is concluded that elevated carbon dioxide increased the responsiveness of corn growth to nitrogen application by increasing the response of leaf area to nitrogen application rate, and that elevated carbon dioxide increased the amount of nitrogen required to achieve maximum yields.展开更多
基金Supported by the National Natural Science Foundation of China (No.29976045).
文摘Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of corn leaf as the reaction time increased. On the contrary, the pH of corn leaf hydrolysate increased more than that of corn stalk with diluted acid addition. Increasing temperature enhanced the xylose dissolution rate and increased cellulose digestibility. Compared with hot water, 0.1% sulfuric acid addition improved the xylan removal and the enzymatic hydrolysis of both corn leaf and corn stalk residue. Much less xylan must be removed to achieve the same cellulose digestibility for the corn leaf as that for the corn stalk; 55% digestibility was obtained when only 32% xylan was removed from corn leaf, whereas corn stalk required removal of about 50% of the xylan to achieve the same di- gestibility. Overall, the descending order of enzymatic digestibility was: dilute acid hydrolysate of corn leaf > dilute acid hydrolysate of corn stalk > water-only hydrolysate of corn leaf > water-only hydrolysate of corn stalk. Finally, one separate pretreatment strategy was developed to transfer corn leaf and corn stalk to fermentable sugars for fur- ther bioenergy production.
基金financially supported by the Key Planning Projects on Science and Technology of Jilin Province,China(20180201012NY)the Inter-Governmental International Cooperation Special Project of National Key R&D Program of China(2019YFE0114200)the National Key R&D Program of China(2017YFD0201802)。
文摘Maize(Zea mays L.), also known as corn, is the third most cultivated crop in the world. Northern corn leaf blight(NCLB) is a globally devastating maize foliar disease caused by Setosphaeria turcica(Luttrell) Leonard and Suggs. Early intelligent diagnosis and warning is an effective and economical strategy to control this disease. Today, deep learning is beginning to play an essential role in agriculture. Notably, deep convolutional neural networks(DCNN) are amongst the most successful machine learning techniques in plant disease detection and diagnosis. Our study aims to identify NCLB in the maize-producing area in Jilin Province based on several DCNN models. We established a database of 985 leaf images of healthy and infected maize and applied data augmentation techniques including image segmentation, image resizing, image cropping, and image transformation, to expand to 30 655 images. Several proven convolutional neural networks, such as AlexNet, Google Net, VGG16, and VGG19, were then used to identify diseases. Based on the best performance of the DCNN pre-trained model Google Net, some of the recent loss functions developed for deep facial recognition tasks such as Arc Face, Cos Face, and A-Softmax were applied to detect NCLB. We found that a pre-trained Google Net architecture with the Softmax loss function can achieve an excellent accuracy of 99.94% on NCLB diagnosis. The analysis was implemented in Python with two deep learning frameworks, Pytorch and Keras. The techniques, training, validation, and test results are presented in this paper. Overall, our study explores intelligent identification technology for NCLB and effectively diagnoses NCLB from images of maize.
文摘Maize is cultivated extensively throughout the world and has the highest production among cereals.However,Northern corn leaf blight(NCLB)disease caused by Exherohilum turcicum,is the most devastating limiting factor of maize production.The disease causes immense losses to corn yield if it develops prior or during the tasseling and silking stages of crop development.It has a worldwide distribution and its development is favoured by cool to moderate temperatures with high relative humidity.The prevalence of the disease has increased in recent years and new races of the pathogen have been reported worldwide.The fungus E.turcicum is highly variable in nature.Though different management strategies have proved effective to reduce economic losses from NCLB,the development of varieties with resistance to E.turcicum is the most efficient and inexpensive way for disease management.Qualitative resistance for NCLB governed by Ht genes is a race-specific resistance which leads to a higher level of resistance.However,some Ht genes can easily become ineffective under the high pressure of virulent strains of the pathogen.Hence,it is imperative to understand and examine the consistency of the genomic locations of quantitative trait loci for resistance to NCLB in diverse maize populations.The breeding approaches for pyramiding resistant genes against E.turcicum in maize can impart NCLB resistance under high disease pressure environments.Furthermore,the genome editing approaches like CRISPR-cas9 and RNAi can also prove vital for developing NCLB resistant maize cultivars.As such this review delivers emphasis on the importance and current status of the disease,racial spectrum of the pathogen,genetic nature and breeding approaches for resistance and management strategies of the disease in a sustainable manner.
基金the National Natural Science Foundation of China (No.29976045).
文摘Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of corn leaf as the reaction time increased. On the contrary, the pH of corn leaf hydrolysate increased more than that of corn stalk with diluted acid addition. Increasing temperature enhanced the xylose dissolution rate and increased cellulose digestibility. Compared with hot water, 0.1% sulfuric acid addition improved the xylan removal and the enzymatic hydrolysis of both corn leaf and corn stalk residue. Much less xylan must be removed to achieve the same cellulose digestibility for the corn leaf as that for the corn stalk; 55% digestibility was obtained when only 32% xylan was removed from corn leaf, whereas corn stalk required removal of about 50% of the xylan to achieve the same di- gestibility. Overall, the descending order of enzymatic digestibility was: dilute acid hydrolysate of corn leaf > dilute acid hydrolysate of corn stalk > water-only hydrolysate of corn leaf > water-only hydrolysate of corn stalk. Finally, one separate pretreatment strategy was developed to transfer corn leaf and corn stalk to fermentable sugars for fur- ther bioenergy production.
文摘Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season.
基金supported by the National Key Basic Research Program of China (973 Program,2009CB118400)
文摘rhml is a major recessive disease resistance locus for Southern corn leaf blight （SCLB）. To further narrow down its genetic position, F2 population and BCIFI population derived from the cross between resistant （H95rhm） and susceptible parents （H95） of maize （Zea mays） were constructed. Using newly developed markers, rhml was initially delimited within an interval of 2.5 Mb, and then finally mapped to a 8.56 kb interval between InDel marker IDP961-503 and simple sequence repeat （SSR） marker A194149--1. Three polymorphic markers IDP961-504, IDP B2-3 and A194149-2 were shown to be co-segregated with the rhml locus. Sequence analysis of the 8.56 kb DNA fragment revealed that it contained only one putative gene with a predicted amino acid sequence identical to lysine histidine transporter 1 （LHT1）. Comparative sequence analysis indicated that the LHT1 in H95rhrn harbors a 354 bp insertion in its third exon as compared with that of susceptible alleles in B73, H95 and Mo17. The 354 bp insertion resulted in a truncation of the predicted protein of candidate resistance allele （LHT1-H95rhm）. Our results strongly suggest LHTI as the candidate gene for rhml against SCLB. The tightly linked molecular markers developed in this study can be directly used for molecular breeding of resistance to Southern corn leaf blight in maize.
基金supported by the National Natural Science Foundation of China (31872872 and U1804113)the National Key Research and Development Program of China (2016YFD0101003)
文摘Southern corn leaf blight (SCLB), caused by Bipolarismaydis, is one of the most devastatingdiseases affecting maize production. However,only one SLCB resistance gene, conferring partialresistance, is currently known, underscoring theimportance of isolating new SCLB resistancerelatedgenes. Here, we performed a comparativeproteomic analysis and identified 258 proteinsshowing differential abundance during the maizeresponse to B. maydis. These proteins included anascorbate peroxidase (Zea mays ascorbate peroxidase1 (ZmAPX1)) encoded by a gene locatedwithin the mapping interval of a previously identifiedquantitative trait locus associated with SCLBresistance. ZmAPX1 overexpression resulted inlower H_(2)O_(2) accumulation and enhanced resistanceagainst B. maydis. Jasmonic acid (JA)contents and transcript levels for JA biosynthesisand responsive genes increased in ZmAPX1-overexpressing plants infected with B. maydis,whereas Zmapx1 mutants showed the oppositeeffects. We further determined that low levels of H_(2)O_(2) are accompanied by an accumulation of JAthat enhances SCLB resistance. These resultsdemonstrate that ZmAPX1 positively regulatesSCLB resistance by decreasing H_(2)O_(2) accumulationand activating the JA-mediated defensesignaling pathway. This study identified ZmAPX1as a potentially useful gene for increasing SCLBresistance. Furthermore, the generated datamay be relevant for clarifying the functions ofplant APXs.
基金Supported by Shanxi Scientific Research Project ( 20090311002-3)Science and Technology Research Project of Shanxi Academy of Agricultural Sciences( YGG0927)~~
文摘[ Objective] The paper was to evaluate the resistance of particular corn hybrids against northern leaf blight. [ Method ] Using artificial inoculation meth- od, the resistance of 238 copies of particular corn hybrids including silage corn, high oil corn, waxy corn and sweet corn against northern leaf blight was evaluated. [ Result] The corn samples with high resistance, resistance, moderate resistance, susceptibility and high susceptibility to northern leaf blight among 238 copies of materials in identification accounted for 0.8%, 20.6%, 44. 1%, 24.8% and 9.7%, respectively. Different types of varieties had significant difference in resist- ance. Among cern varieties with moderate resistance or higher level, silage corn accounted for 87.8% ; high oil corn and waxy corn accounted for 73.3% and 61.3 %, respectively; sweet corn was less, accounting for 44.2%. Sixteen of 30 approved particular corn varieties showed resistance, accounting for 53.3 % of total approved varieties. [Condusion] The paper provided theoretical basis for breeding and planting of particular corn hybrids with resistance against northern leaf blight.
文摘The northem corn leaf blight is one of the most serious diseases in maize production. The research progress on etiology, generation law and control strategy, antigen identification, resistance mechanism and inheritance of this disease was discussed. And the research work which should be enhanced in China was pointed out, such as mechanism of resistance inheritance, developing function marker, gene mining, screening resistance resource and dominant physiological race in different areas.
文摘Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration with early- to mid- season plant height of corn at Milan, TN from 2008 to 2010 using linear, quadratic, square root, logarithmic, and exponential models. Six N rate treatments (0, 62, 123, 185, 247, and 308 kg·N·ha-1) repeated four times were implemented each year in a randomized complete block design under four major cropping systems: corn after corn, corn after soybean [Glycine max (L.) Merr.], corn after cotton [Gossypium hirsutum (L.)], and irrigated corn after soybean. The relationship of ear leaf N concentration determined at the blister growth stage (R2) with plant height measured at the 6-leaf (V6), 10-leaf (V10), and 12-leaf (V12) growth stages was statistically significant and positive in non-irrigated corn under normal weather conditions. However, the strength of this relationship was weak to moderate with the determination coefficient (R2) values ranging from 0.21 to 0.51. This relationship was generally improved as the growing season progressed from V6 to V12. Irrigation and abnormal weather seemed to have adverse effects on this relationship. The five regression models performed similarly in the evaluation of this relationship regardless of growth stage, year, and cropping system. Our results suggest that unlike the relationship of corn yield at harvest with plant height measured during early- to mid-season or the relationship of leaf N concentration with plant height when both are measured simultaneously during early- to mid-season, the relationship of late-season ear leaf N concentration with early- to mid-season plant height may not be strong enough to be used to develop algorithms for variable-rate N applications on corn within a field no matter which regression model is used to describe this relationship.
基金This work was supported by the National Natural Science Foundation of China(51975245 and 52075214)Jilin Provincial Science&Technology Department(20200201058JC and 20190303039SF)+3 种基金Key Science and Technology R&D Projects of Jilin Province(2020C023-3)Program of Jilin University Science and Technology Innovative Research Team(2020TD-03)Youth Development Program of Jilin University(2020-JCXK-22)the Fundamental Research Funds for the Central Universities.
文摘Designing bio-inspired flow fields holds great potential in improving the performance of Proton Exchange Membrane Fuel Cell(PEMFC).Two kinds of biological prototypes are widely used:plant prototype and animal prototype.It remains a question which one of these prototypes is more appropriate for the scenario of PEMFC.Here,a comparative study was conducted to compare bionic flow fields based on animal and plant prototypes.First,a Corn Leaf Vein Mathematical Model(CLMM)was established by extracting structural parameters from corn leaves of two growth stages.Then the obtained CLMM and well-known Murray’s law were employed to design bionic flow fields corresponding to the plant and animal prototypes,respectively,which have been subsequently compared by numerical investigations.The results demonstrate that the flow field guided by Murray’s law outperforms the counterpart based on the structural parameters of CLMM in terms of PEMFC net output power,mass transport,water management and pressure drop,suggesting that animal circulation system is more suitable to the bionic flow field design of PEMFC than plant leaf veins.The work may also offer valuable insights into the design of other flow fields related to electrochemical energy conversion.
文摘Fifteen field trials were conducted from 2009 to 2011 in Ontario, Canada and Michigan, USA to determine how long glyphosate-resistant corn needs to be kept weed-free after emergence to prevent yield loss. Data were separated into two environments based on when yield loss first occurred after glyphosate application. In Environment 1 (4/15 sites) yield was not reduced when corn was kept weed-free until the 4-leaf stage. However, in Environment 2 (11/15 sites) there was no yield loss when corn was kept weed-free up to the 2-leaf stage. The most prominent weeds were velvetleaf, redroot pigweed, common ragweed, common lambsquarters and foxtail species. While later emerging weeds did not necessarily impact corn yield, weeds emerging after the 2- and 4-leaf corn stage likely produced seed that was added to the soil seed bank. Weeds emerging after 6-, 8-, and 10-leaf corn growth stages were small (low biomass/seedlings) and most likely did not reach reproductive maturity. Based on this research, corn must be maintained weed-free up to the 4-leaf stage. Any weeds emerging after that did not influence corn yield.
基金Supported by Key Research and Development Program of Shandong Province(2016CYJS03A01-1)Key Technology Research of Precision Agriculture(CXGC2017B04)+1 种基金Key Application Technological Innovation Project of Agriculture in Shandong Province"Research and Application of Key Technologies for Early Rapid Identification of Wheat Diseases"Young Scholar Scientific Research Foundation of Shandong Academy of Agricultural Sciences"Study on Rapid Extraction Technology for County-wide Farmland Based on High Resolution Remote Sensing Image"(2015YQN47)
文摘This study is aimed to explore the spectrum reflection characteristics of summer corn leaves in different fertilization conditions.Using hyperspectral remote sensing technology,the experiments were conducted in fields to collect the hyperspectral images of Denghai 605( DH605) and Ludan 981( LD981) in different growth period under five fertilization treatments,and then the reflectance of corn ear leaves was extracted by ENVI software. The five fertilization treatments included the control( CK) with no fertilization,40 kg and 30 kg of controlled-release fertilizer per 666. 67 m2 as base( K40 and K30),50 kg and 40 kg of compound fertilizer per 666. 67 m2 as base with 15 kg urea as seed fertilizer( F50 + N and F40 + N). The reflectance spectrums of the two corn cultivars under different fertilization treatments showed the approximately same changing trend with a reflection peak at green band( 550 nm) and a higher reflection platform at near infrared band( 760 nm-1050 nm). At the heading to filling stage,the reflectance of DH605 and LD981 was the highest under the CK,followed by the K30 and F40 + N respectively. At the filling to dough stage,the reflectance of DH605 and LD981 was the highest under the treatment K30 and F40 + N respectively,which was obviously higher than that of the other treatments. In the conditions of compound fertilizer,except the late filling stage,LD981 had little higher reflectance than DH605 at the other stages. In the conditions of controlled-release fertilizer and at dough to mature stage,LD981 had obviously higher reflectance compared to the other stages,and also higher than that of DH605; there was not obvious difference in reflectance LD981 and DH605 at the other stages.
文摘[目的]明确36%烯肟·氟环唑SC对玉米小斑病的防治效果。[方法]以17%唑醚·氟环唑SC和30%肟菌·戊唑醇SC为对照药剂,在山东省潍坊市寒亭区高里街道河南村玉米田进行田间小区试验。[结果]36%烯肟·氟环唑SC81、108 g a.i./hm^(2)处理对玉米小斑病效果优于对照药剂17%唑醚·氟环唑SC和30%肟菌·戊唑醇SC,54 g a.i./hm^(2)的36%烯肟·氟环唑SC处理对玉米小斑病效果与对照药剂无显著性差异。[结论]使用36%烯肟·氟环唑SC54~108 g a.i./hm^(2)在玉米小斑病发病前或发病初期茎叶均匀喷雾,间隔7~10 d再施用1次,可有效防治玉米小斑病。
文摘Corn, with C4 photosynthetic metabolism, often has no photosynthetic or yield response to elevated carbon dioxide concentrations. In C3 species, the yield stimulation at elevated carbon dioxide concentrations often decreases with nitrogen limitation. I tested whether such a nitrogen interaction occurred in corn, by growing sweet corn in field plots in open top chambers at ambient and elevated (ambient + 180 mmol·mol-1) carbon dioxide concentrations for four seasons, with six nitrogen application rates, ranging from half to twice the locally recommended rate. At the recommended rate of nitrogen application, no carbon dioxide effect on production occurred. However, both ear and leaf plus stem biomass were lower for the elevated carbon dioxide treatment than for the ambient treatment at less than the recommended rate of nitrogen application, and higher at the highest rates of nitrogen application. There were no significant responses of mid-day leaf gas exchange rates to nitrogen application rate for either carbon dioxide treatment, and elevated carbon dioxide did not significantly increase leaf carbon dioxide assimilation rates at any nitrogen level. Leaf area index during vegetative growth increased more with nitrogen application rate at elevated than at ambient carbon dioxide. It is concluded that elevated carbon dioxide increased the responsiveness of corn growth to nitrogen application by increasing the response of leaf area to nitrogen application rate, and that elevated carbon dioxide increased the amount of nitrogen required to achieve maximum yields.
