As the most important cultural practices for ramie （Boehmeria nivea） production, the single effects of plant density and nitrogen （N）, phosphorus （P）, potassium （K） fertilization on yield are well documented. ...As the most important cultural practices for ramie （Boehmeria nivea） production, the single effects of plant density and nitrogen （N）, phosphorus （P）, potassium （K） fertilization on yield are well documented. To achieve the high yield and quality of ramie fiber, it is principal to quantify the fertilizer dosage for ramie sustainable production. A central composite design （CCD） was adopted with three replications, for a two-year field experiment （2008-2009） in the Yangtze River Valley of China. The aim was to evaluate both the individual and combined effects of plant density and N, P, and K fertilization on yield and fiber quality. The effects of the four factors on yield and quality of ramie cultivar Huazhu 4 were tested. Then mathematical models of the relationship among the four factors affecting ramie production and quality were established and analyzed to optimize the four factors, and used to establish optimum cultivation methods for the elite cultivar suitable to this area of the Yangtze River Valley. Supplements of N （X2）, P 0（3） and K 0（4）, and the density （X0 with N （X2） interaction significantly influenced strength in tests of mature ramie. The influence on fiber yield in the two year tests by the four factors ranked as follows： X3〉X4〉X~〉X2. We established the optimization technique attaining yield of 2 600 kg ha-~ in the tests as following： density of 28 350-31 650 plants ha-1, and supplements of N, P and K of 363-387, 98.58-105.48 and 280.20- 319.8 kg ha-1, respectively. It was concluded that nitrogen mostly improved plant growth and fiber yield while potassium had discernible effects on fiber quality.展开更多
Gene expression profiling at early stages(0～2 DPA) of fiber development in Gossypium hirsutum identified a number of transcription factors which were down regulated in fiberless mutants relative to wild type controls...Gene expression profiling at early stages(0～2 DPA) of fiber development in Gossypium hirsutum identified a number of transcription factors which were down regulated in fiberless mutants relative to wild type controls and which could play a role in controlling early fiber development.Chief among these was GhMYB25,a Mixta-like MYB gene.Transgenic GhMYB25-silenced cotton展开更多
Cotton,the most important natural fiber crop in the world,is a mainstay in China's economy.However,for over two decades,cotton yields both in China and U.S.have been at a plateau.
Fiber productivity and quality of cotton are severely affected by abiotic stresses.In this study,we identified the role of GhADF1,an actin depolymerizing factor,in cotton response to drought stress.GhADF1 expression i...Fiber productivity and quality of cotton are severely affected by abiotic stresses.In this study,we identified the role of GhADF1,an actin depolymerizing factor,in cotton response to drought stress.GhADF1 expression in cotton could be induced by PEG6000.GhADF1-RNAi transgenic cotton showed increased tolerance to drought stress during seed germination and seedling development as well as at the reproductive stage.In contrast,overexpression of GhADF1 led to a drought-sensitive phenotype in transgenic plants.GhADF1-RNAi plants produced an enlarged root system with longer primary roots,more lateral roots,increased root dry biomass,and increased cell size.In leaves of GhADF1-RNAi cotton,proline content and activities of reactive oxygen species-scavenging enzymes were increased following drought stress compared with those in wild type.GhADF1-RNAi lines showed higher water-use efficiency than the wild type,accompanied by reduced leaf stomatal density and conductance.GhADF1-RNAi cotton produced higher fiber yield in the field under both normal and drought conditions.Transcriptomic analyses identified 124 differentially expressed genes in leaves of GhADF1-RNAi lines compared with the wild type following drought treatment.Upregulated genes included those encoding transcription factors,protein kinases,heat shock proteins,and other proteins known to be involved in stress responses.We conclude that GhADF1 reduces the expression of abiotic stress-associated genes in cotton response to drought stress and may be a promising candidate gene for crop improvement by genetic manipulation.展开更多
Soil alkali-hydrolyzable nitrogen, which is sensitive to N fertilization rate, is one of the indicators of soil nitrogen supplying capacity. Two field experiments were conducted in Dongtai(120°19″ E, 32°52...Soil alkali-hydrolyzable nitrogen, which is sensitive to N fertilization rate, is one of the indicators of soil nitrogen supplying capacity. Two field experiments were conducted in Dongtai(120°19″ E, 32°52″ N), Jiangsu, China in 2009 and Dafeng(120°28″ E, 33°12″ N), Jiangsu province, China in 2010. Six nitrogen rates(0, 150, 300, 375, 450, and 600 kg ha^(-1)) were used to study the effect of N fertilization rate on soil alkali-hydrolyzable nitrogen content(SAHNC), subtending leaf nitrogen concentration(SLNC), yield, and fiber quality. In both Dongtai and Dafeng experiment station, the highest yield(1709 kg ha^(-1)), best quality(fiber length 30.6 mm, fiber strength 31.6 c N tex^(-1), micronaire 4.82), and highest N agronomic efficiency(2.03 kg kg^(-1)) were achieved at the nitrogen fertilization rate of 375 kg ha^(-1). The dynamics of SAHNC and SLNC could be simulated with a cubic and an exponential function,respectively. The changes in SAHNC were consistent with the changes in SLNC. Optimal average rate(0.276 mg day^(-1)) and duration(51.8 days) of SAHNC rapid decline were similar to the values obtained at the nitrogen rate of 375 kg ha^(-1)at which cotton showed highest fiber yield, quality, and N agronomic efficiency. Thus, the levels and strategies of nitrogen fertilization can affect SAHNC dynamics. The N fertilization rate that optimizes soil alkali-hydrolyzable nitrogen content would optimize the subtending leaf nitrogen concentration and thereby increase the yield and quality of the cotton fiber.展开更多
Winter fiber flax has been planted in a large area in Yunnan Province, the southwestern part of China, and other areas of the world, but little is known about the influence of fertilization on the fiber yield and qual...Winter fiber flax has been planted in a large area in Yunnan Province, the southwestern part of China, and other areas of the world, but little is known about the influence of fertilization on the fiber yield and quality. For that, a two-factor experiment in random block designed was carried out by specifying nitrogen (N), phosphorus (P) and potassium (K) as factor A, boron (B), manganese (Mn), copper (Cu), zinc (Zn) and molybdenum (Mo) as factor B each in four levels and their complete combinations. With the increase of N, P and K fertilizers, the yields of long-fiber and total-fiber obviously increased resulting from the increased straw yield, although the portion of retted-stem in straw, contents of longfiber and total-fiber decreased. The fiber tensile strength and flexibility increased as well. The micronutrients application increased the yields of straw, long-fiber and total-fiber, but gave no influence to fiber content and the fiber qualities. Combinations of the macronutrients and micronutrients gave obvious influences to the yields of straw and fiber, contents of long-fiber and total-fiber, fiber fineness and tensile strength, but little influence to the fiber flexibility. The fertilizers formula A2B2, i.e. N-P2O5-K2O 172.8, 28.8 172.8 kg/hm2, Zn-Cu-B-M-Mo 2363, 1654, 236, 2363,165 g/hm2, was the best, yielding most in the straw, long-fiber and total-fiber, with synchronous improvement of the three quality indices.展开更多
To introgress elite QTL alleles of Gossypium barbadense L.for fiber yield and quality and resistance to Verticillium wilt into G.hirsutum L.,enlarge the genetic base of G.hirsutum,and
Heat waves,and an increased number of warm days and nights,have become more prevalent in major agricultural regions of the world.Although well adapted to semi-arid regions,cotton is vulnerable to high temperatures,par...Heat waves,and an increased number of warm days and nights,have become more prevalent in major agricultural regions of the world.Although well adapted to semi-arid regions,cotton is vulnerable to high temperatures,particularly during flowering and boll development.To maintain lint yield potential without compromising its quality under high-temperature stress,it is essential to understand the effects of heat stress on various stages of plant growth and development,and associated tolerance mechanisms.Despite ongoing efforts to gather data on the effects of heat stress on cotton growth and development,there remains a critical gap in understanding the distinct influence of high temperatures during the day and night on cotton yield and quality.Also,identifying mechanisms and target traits that induce greater high day and night temperature tolerance is essential for breeding climate-resilient cotton for future uncertain climates.To bridge these knowledge gaps,we embarked on a rigorous and comprehensive review of published literature,delving into the impact of heat stress on cotton yields and the consequential losses in fiber quality.This review encompasses information on the effects of heat stress on growth,physiological,and biochemical responses,fertilization,cotton yield,and quality.Additionally,we discuss management options for minimizing heat stress-induced damage,and the benefits of integrating conventional and genomics-assisted breeding for developing heat-tolerant cotton cultivars.Finally,future research areas that need to be addressed to develop heat-resilient cotton are proposed.展开更多
Two cotton（Gossypium hirsutum L.） cultivars, Kemian 1（cool temperature-tolerant） and Sumian 15（cool temperaturesensitive） were used to study the effects of cool temperature on carbohydrates, yield, and fiber qua...Two cotton（Gossypium hirsutum L.） cultivars, Kemian 1（cool temperature-tolerant） and Sumian 15（cool temperaturesensitive） were used to study the effects of cool temperature on carbohydrates, yield, and fiber quality in cotton bolls located at different fruiting positions（FP）. Cool temperatures were created using late planting and low light. The experiment was conducted in 2010 and 2011 using two planting dates（OPD, the optimized planting date, 25 April; LPD, the late planting date, 10 June） and two shading levels of crop relative light rate（CRLR, 100 and 60%）. Compared with fruiting position 1（FP1）, cotton yield and yield components（fiber quality, leaf sucrose and starch content, and fiber cellulose） were all decreased on FP3 under all treatments. Compared with OPD-CRLR 100%, other treatments（OPD-CRLR 60%, LPD-CRLR 100%, and LPD-CRLR 60%） had significantly decreased lint yield at both FPs of both cultivars, but especially at FP3 and in Sumian 15; this decrease was mainly caused by a large decline in boll number. All fiber quality indices decreased under late planting and shading except fiber length at FP1 with OPD-CRLR 60%, and a greater reduction was observed at FP3 and in Sumian 15. Sucrose content of the subtending leaf and fiber increased under LPD compared to OPD, whereas it decreased under CRLR 60% compared to CRLR 100%, which led to decreased fiber cellulose content. Therefore, shading primarily decreased the ＂source＂ sucrose content in the subtending leaf whereas late planting diminished translocation of sucrose towards cotton fiber. Notably, as planting date was delayed and light was decreased, more carbohydrates were distributed to leaf and bolls at FP1 than those at FP3, resulting in higher yield and better fiber quality at FP1, and a higher proportion of bolls and carbohydrates allocated at FP3 of Kemian 1 compared to that of Sumian 15. In conclusion, cotton yield and fiber quality were reduced less at FP1 compared to those at FP3 under low temperature and low light conditions. Thus, reduced cotton yield and fiber quality loss can be minimized by selecting low temperature tolerant cultivars under both low temperature and light conditions.展开更多
Background:Cotton is a significant economic crop that plays an indispensable role in many domains.Gossypium hirsutum L.is the most important fiber crop worldwide and contributes to more than 95%of global cotto n produ...Background:Cotton is a significant economic crop that plays an indispensable role in many domains.Gossypium hirsutum L.is the most important fiber crop worldwide and contributes to more than 95%of global cotto n production.Identifying stable quantitative trait locus(QTLs)controlling fiber quality and yield related traits are necessary prerequisites for marker-assisted selection(MAS).Results:A genetic linkage map was constructed with 312 simple sequence repeat(SSR)loci and 35 linkage groups using JoinMap 4.0;the map spanned 1 929.9 cM,with an average interval between two markers of 6.19 cM,and covered approximately 43.37%of the cotton genome.A total of 74 QTLs controlling fiber quality and 41 QTLs controlling yield-related traits were identified in 4 segregating generations.These QTLs were distributed across 20 chromosomes and collectively explained 1.01%?27.80%of the observed phenotypic variations.In particular,35 stable QTLs could be identified in multiple generations,25 common QTLs were con sistent with those in previous studies,and 15 QTL clusters were found in 11 chromosome segments.Conclusion:These studies provide a theoretical basis for improving cotton yield and fiber quality for molecular marker-assisted selection.展开更多
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
棉花伏前桃、伏桃、早秋桃和晚秋桃(“四桃”)的时空分布不同,但目前“四桃”的纤维产量和品质差异及其对氮(N)肥与缩节胺(DPC)配施的响应鲜见报道。2015—2017年,在郑州市黄河滩区采用双因素裂区设计,以3个N肥用量为主区,即不施N肥(N0...棉花伏前桃、伏桃、早秋桃和晚秋桃(“四桃”)的时空分布不同,但目前“四桃”的纤维产量和品质差异及其对氮(N)肥与缩节胺(DPC)配施的响应鲜见报道。2015—2017年,在郑州市黄河滩区采用双因素裂区设计,以3个N肥用量为主区,即不施N肥(N0)、常量施N(N1)和过量施N(N2),用量分别为0、225和450 kg hm-2;以3个DPC用量为副区,即不喷施DPC(D0)、常量DPC(D1)和过量DPC(D2),用量分别为0、75和150 g hm-2。研究了N肥与DPC配施对棉花纤维产量及品质时间分布的影响。结果表明,(1)N1处理的“四桃”纤维产量比N0和N2处理分别增加36.79%和3.27%, N2处理减产不显著;D1处理比D0和D2处理分别增产17.53%和8.50%, D2处理减产达到显著水平;N1D1组合产量最高,其余组合减产1.15%~51.53%。N1D1组合的伏前桃、伏桃、早秋桃和晚秋桃产量分别占8.89%、45.35%、33.41%和12.36%,伏桃和早秋桃是产量主体,但早秋桃的成产强度大。随着施N量增加,早秋桃和晚秋桃的纤维产量占比增加,而随着DPC用量增加则表现相反。(2) N肥用量和DPC用量均对纤维长度、整齐度、比强度和马克隆值有显著影响,但对纤维伸长率影响达不到显著水平。N1处理和D1处理的纤维品质综合表现最优,但D0处理马克隆值最佳。N肥与DPC用量互作对“四桃”的纤维比强度和马克隆值有显著影响,其中, N1D1处理“四桃”的比强度和马克隆值均表现最优,而N2D2处理“四桃”的比强度和马克隆值表现最差。此外,过量施N和过量喷施DPC均会升高马克隆值。(3)“四桃”的纤维品质存在差异。伏前桃的纤维品质除马克隆值最优外,其纤维长度、整齐度和比强度最差;伏桃和早秋桃的纤维长度、整齐度和比强度最优,但马克隆值表现最差,伸长率居中;晚秋桃的伸长率最优,其余品质指标均居中。研究结果丰富了“四桃”产量和品质差异的相关理论,并为棉花合理施N和喷施DPC以及“四桃”纤维的合理利用提供了科学依据。展开更多
Genetic diversity provides the foundation for crop improvement. Genetic variation and associations among Cotton Leaf Curl Disease (CLCuD), fiber and yield related traits were investigated in exotic lines of Gossypium ...Genetic diversity provides the foundation for crop improvement. Genetic variation and associations among Cotton Leaf Curl Disease (CLCuD), fiber and yield related traits were investigated in exotic lines of Gossypium arboreum L. in an experimental field at the Central Cotton Research Institute (CCRI), Multan, Pakistan during the crop season 2011-12. One hundred and nineteen (119) accessions imported from USA through the Pakistan and US “Cotton Productivity Enhancement Program” (CPEP), were evaluated in this study. Various statistical approaches including descriptive statistics, correlation and principal component analysis was performed to evaluate and identify desirable genotypes. Results revealed that seed cotton yield was significantly and positively correlated with boll weight and number of bolls plant-1. Similarly, plant height was also significantly correlated with sympodial branches, lint percentage and micronaire value. Lint percentage showed a highly significant and positive correlation with plant height, sympodial branches and micronaire value. With respect to fiber traits, negative and significant relationships were observed between the micronaire value (MIC) and fiber strength. CLCuD showed no relationship with any of the studied traits, as all the G. arboreum L. lines evaluated were scored resistant to CLCuD. Principal component analysis (PCA) showed that the first four out of 11 components contributed about 65.88% of the total variation having an eigen value greater than 1. Based on PCA, the genotypes GS-4, GS-9, GS-8, GS-55 and GS-50 could be utilized successfully in a future breeding program based on having the highest positive loading factor for staple length (0.135) in PC1 and seed cotton yield (0.625), number of bolls plant-1, boll weight, first sympodial nod, staple length and fiber strength in PC2 respectively.展开更多
A new modification for the shear lag model is given and the expressions for the stiffness and yield Strength of short fiber metal matri×composite are derived. These expressions are then compared with our experime...A new modification for the shear lag model is given and the expressions for the stiffness and yield Strength of short fiber metal matri×composite are derived. These expressions are then compared with our experimental data in a SiCw/Al-Li T6 composite and the published experimental data on different SiCw/Al T6 composites and also compared with the previous shear lag models and the other theoretical models.展开更多
基金the National Natural Science Foundation of China (31000731)China Agriculture Research System (CARS-19-E12)
文摘As the most important cultural practices for ramie （Boehmeria nivea） production, the single effects of plant density and nitrogen （N）, phosphorus （P）, potassium （K） fertilization on yield are well documented. To achieve the high yield and quality of ramie fiber, it is principal to quantify the fertilizer dosage for ramie sustainable production. A central composite design （CCD） was adopted with three replications, for a two-year field experiment （2008-2009） in the Yangtze River Valley of China. The aim was to evaluate both the individual and combined effects of plant density and N, P, and K fertilization on yield and fiber quality. The effects of the four factors on yield and quality of ramie cultivar Huazhu 4 were tested. Then mathematical models of the relationship among the four factors affecting ramie production and quality were established and analyzed to optimize the four factors, and used to establish optimum cultivation methods for the elite cultivar suitable to this area of the Yangtze River Valley. Supplements of N （X2）, P 0（3） and K 0（4）, and the density （X0 with N （X2） interaction significantly influenced strength in tests of mature ramie. The influence on fiber yield in the two year tests by the four factors ranked as follows： X3〉X4〉X~〉X2. We established the optimization technique attaining yield of 2 600 kg ha-~ in the tests as following： density of 28 350-31 650 plants ha-1, and supplements of N, P and K of 363-387, 98.58-105.48 and 280.20- 319.8 kg ha-1, respectively. It was concluded that nitrogen mostly improved plant growth and fiber yield while potassium had discernible effects on fiber quality.
文摘Gene expression profiling at early stages(0～2 DPA) of fiber development in Gossypium hirsutum identified a number of transcription factors which were down regulated in fiberless mutants relative to wild type controls and which could play a role in controlling early fiber development.Chief among these was GhMYB25,a Mixta-like MYB gene.Transgenic GhMYB25-silenced cotton
基金This work is supported by the Major State Basic Research Development Program of China(2004CB117300)the National Natural Science Foundation of China (30530490)
文摘Cotton,the most important natural fiber crop in the world,is a mainstay in China's economy.However,for over two decades,cotton yields both in China and U.S.have been at a plateau.
基金supported by the National Natural Science Foundation of China(31601350)the Project of Transgenic Research from the Ministry of Science and Technology of China(2016ZX08005-004-007)+1 种基金the Fundamental Research Project of Shanxi Province(20210302123381)the Science and Technology Innovation Project of Higher Education Institutions of Shanxi Province(2021L115).
文摘Fiber productivity and quality of cotton are severely affected by abiotic stresses.In this study,we identified the role of GhADF1,an actin depolymerizing factor,in cotton response to drought stress.GhADF1 expression in cotton could be induced by PEG6000.GhADF1-RNAi transgenic cotton showed increased tolerance to drought stress during seed germination and seedling development as well as at the reproductive stage.In contrast,overexpression of GhADF1 led to a drought-sensitive phenotype in transgenic plants.GhADF1-RNAi plants produced an enlarged root system with longer primary roots,more lateral roots,increased root dry biomass,and increased cell size.In leaves of GhADF1-RNAi cotton,proline content and activities of reactive oxygen species-scavenging enzymes were increased following drought stress compared with those in wild type.GhADF1-RNAi lines showed higher water-use efficiency than the wild type,accompanied by reduced leaf stomatal density and conductance.GhADF1-RNAi cotton produced higher fiber yield in the field under both normal and drought conditions.Transcriptomic analyses identified 124 differentially expressed genes in leaves of GhADF1-RNAi lines compared with the wild type following drought treatment.Upregulated genes included those encoding transcription factors,protein kinases,heat shock proteins,and other proteins known to be involved in stress responses.We conclude that GhADF1 reduces the expression of abiotic stress-associated genes in cotton response to drought stress and may be a promising candidate gene for crop improvement by genetic manipulation.
基金funded by the National Key Technology R&D Program of China (No. 2014BAD11B02)the Special Fund for Agro-scientific Research in the Public Interest (No. 201203096)+1 种基金the National Natural Science Foundation of China (Nos. 31401327, 30971735)the China Agriculture Research System (No. CARS-18-20)
文摘Soil alkali-hydrolyzable nitrogen, which is sensitive to N fertilization rate, is one of the indicators of soil nitrogen supplying capacity. Two field experiments were conducted in Dongtai(120°19″ E, 32°52″ N), Jiangsu, China in 2009 and Dafeng(120°28″ E, 33°12″ N), Jiangsu province, China in 2010. Six nitrogen rates(0, 150, 300, 375, 450, and 600 kg ha^(-1)) were used to study the effect of N fertilization rate on soil alkali-hydrolyzable nitrogen content(SAHNC), subtending leaf nitrogen concentration(SLNC), yield, and fiber quality. In both Dongtai and Dafeng experiment station, the highest yield(1709 kg ha^(-1)), best quality(fiber length 30.6 mm, fiber strength 31.6 c N tex^(-1), micronaire 4.82), and highest N agronomic efficiency(2.03 kg kg^(-1)) were achieved at the nitrogen fertilization rate of 375 kg ha^(-1). The dynamics of SAHNC and SLNC could be simulated with a cubic and an exponential function,respectively. The changes in SAHNC were consistent with the changes in SLNC. Optimal average rate(0.276 mg day^(-1)) and duration(51.8 days) of SAHNC rapid decline were similar to the values obtained at the nitrogen rate of 375 kg ha^(-1)at which cotton showed highest fiber yield, quality, and N agronomic efficiency. Thus, the levels and strategies of nitrogen fertilization can affect SAHNC dynamics. The N fertilization rate that optimizes soil alkali-hydrolyzable nitrogen content would optimize the subtending leaf nitrogen concentration and thereby increase the yield and quality of the cotton fiber.
文摘Winter fiber flax has been planted in a large area in Yunnan Province, the southwestern part of China, and other areas of the world, but little is known about the influence of fertilization on the fiber yield and quality. For that, a two-factor experiment in random block designed was carried out by specifying nitrogen (N), phosphorus (P) and potassium (K) as factor A, boron (B), manganese (Mn), copper (Cu), zinc (Zn) and molybdenum (Mo) as factor B each in four levels and their complete combinations. With the increase of N, P and K fertilizers, the yields of long-fiber and total-fiber obviously increased resulting from the increased straw yield, although the portion of retted-stem in straw, contents of longfiber and total-fiber decreased. The fiber tensile strength and flexibility increased as well. The micronutrients application increased the yields of straw, long-fiber and total-fiber, but gave no influence to fiber content and the fiber qualities. Combinations of the macronutrients and micronutrients gave obvious influences to the yields of straw and fiber, contents of long-fiber and total-fiber, fiber fineness and tensile strength, but little influence to the fiber flexibility. The fertilizers formula A2B2, i.e. N-P2O5-K2O 172.8, 28.8 172.8 kg/hm2, Zn-Cu-B-M-Mo 2363, 1654, 236, 2363,165 g/hm2, was the best, yielding most in the straw, long-fiber and total-fiber, with synchronous improvement of the three quality indices.
文摘To introgress elite QTL alleles of Gossypium barbadense L.for fiber yield and quality and resistance to Verticillium wilt into G.hirsutum L.,enlarge the genetic base of G.hirsutum,and
基金supported by Cotton Incorporated(Project#22-494)。
文摘Heat waves,and an increased number of warm days and nights,have become more prevalent in major agricultural regions of the world.Although well adapted to semi-arid regions,cotton is vulnerable to high temperatures,particularly during flowering and boll development.To maintain lint yield potential without compromising its quality under high-temperature stress,it is essential to understand the effects of heat stress on various stages of plant growth and development,and associated tolerance mechanisms.Despite ongoing efforts to gather data on the effects of heat stress on cotton growth and development,there remains a critical gap in understanding the distinct influence of high temperatures during the day and night on cotton yield and quality.Also,identifying mechanisms and target traits that induce greater high day and night temperature tolerance is essential for breeding climate-resilient cotton for future uncertain climates.To bridge these knowledge gaps,we embarked on a rigorous and comprehensive review of published literature,delving into the impact of heat stress on cotton yields and the consequential losses in fiber quality.This review encompasses information on the effects of heat stress on growth,physiological,and biochemical responses,fertilization,cotton yield,and quality.Additionally,we discuss management options for minimizing heat stress-induced damage,and the benefits of integrating conventional and genomics-assisted breeding for developing heat-tolerant cotton cultivars.Finally,future research areas that need to be addressed to develop heat-resilient cotton are proposed.
基金supported by the National Natural Science Foundation of China (31271654, 31401327, 31471444)the Special Fund for Agro-scientific Research in the Public Interest, China (201203096)the Jiangsu Overseas Research & Training Program for University Prominent Young & Middle-aged Teachers and Presidents, China (2016)
文摘Two cotton（Gossypium hirsutum L.） cultivars, Kemian 1（cool temperature-tolerant） and Sumian 15（cool temperaturesensitive） were used to study the effects of cool temperature on carbohydrates, yield, and fiber quality in cotton bolls located at different fruiting positions（FP）. Cool temperatures were created using late planting and low light. The experiment was conducted in 2010 and 2011 using two planting dates（OPD, the optimized planting date, 25 April; LPD, the late planting date, 10 June） and two shading levels of crop relative light rate（CRLR, 100 and 60%）. Compared with fruiting position 1（FP1）, cotton yield and yield components（fiber quality, leaf sucrose and starch content, and fiber cellulose） were all decreased on FP3 under all treatments. Compared with OPD-CRLR 100%, other treatments（OPD-CRLR 60%, LPD-CRLR 100%, and LPD-CRLR 60%） had significantly decreased lint yield at both FPs of both cultivars, but especially at FP3 and in Sumian 15; this decrease was mainly caused by a large decline in boll number. All fiber quality indices decreased under late planting and shading except fiber length at FP1 with OPD-CRLR 60%, and a greater reduction was observed at FP3 and in Sumian 15. Sucrose content of the subtending leaf and fiber increased under LPD compared to OPD, whereas it decreased under CRLR 60% compared to CRLR 100%, which led to decreased fiber cellulose content. Therefore, shading primarily decreased the ＂source＂ sucrose content in the subtending leaf whereas late planting diminished translocation of sucrose towards cotton fiber. Notably, as planting date was delayed and light was decreased, more carbohydrates were distributed to leaf and bolls at FP1 than those at FP3, resulting in higher yield and better fiber quality at FP1, and a higher proportion of bolls and carbohydrates allocated at FP3 of Kemian 1 compared to that of Sumian 15. In conclusion, cotton yield and fiber quality were reduced less at FP1 compared to those at FP3 under low temperature and low light conditions. Thus, reduced cotton yield and fiber quality loss can be minimized by selecting low temperature tolerant cultivars under both low temperature and light conditions.
基金supported by the National Natural Science Foundation of China(31371668)the National Agricultural Science and Technology Innovation project for CAAS(CAAS-ASTIP-2016-ICR)
文摘Background:Cotton is a significant economic crop that plays an indispensable role in many domains.Gossypium hirsutum L.is the most important fiber crop worldwide and contributes to more than 95%of global cotto n production.Identifying stable quantitative trait locus(QTLs)controlling fiber quality and yield related traits are necessary prerequisites for marker-assisted selection(MAS).Results:A genetic linkage map was constructed with 312 simple sequence repeat(SSR)loci and 35 linkage groups using JoinMap 4.0;the map spanned 1 929.9 cM,with an average interval between two markers of 6.19 cM,and covered approximately 43.37%of the cotton genome.A total of 74 QTLs controlling fiber quality and 41 QTLs controlling yield-related traits were identified in 4 segregating generations.These QTLs were distributed across 20 chromosomes and collectively explained 1.01%?27.80%of the observed phenotypic variations.In particular,35 stable QTLs could be identified in multiple generations,25 common QTLs were con sistent with those in previous studies,and 15 QTL clusters were found in 11 chromosome segments.Conclusion:These studies provide a theoretical basis for improving cotton yield and fiber quality for molecular marker-assisted selection.
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
文摘棉花伏前桃、伏桃、早秋桃和晚秋桃(“四桃”)的时空分布不同,但目前“四桃”的纤维产量和品质差异及其对氮(N)肥与缩节胺(DPC)配施的响应鲜见报道。2015—2017年,在郑州市黄河滩区采用双因素裂区设计,以3个N肥用量为主区,即不施N肥(N0)、常量施N(N1)和过量施N(N2),用量分别为0、225和450 kg hm-2;以3个DPC用量为副区,即不喷施DPC(D0)、常量DPC(D1)和过量DPC(D2),用量分别为0、75和150 g hm-2。研究了N肥与DPC配施对棉花纤维产量及品质时间分布的影响。结果表明,(1)N1处理的“四桃”纤维产量比N0和N2处理分别增加36.79%和3.27%, N2处理减产不显著;D1处理比D0和D2处理分别增产17.53%和8.50%, D2处理减产达到显著水平;N1D1组合产量最高,其余组合减产1.15%~51.53%。N1D1组合的伏前桃、伏桃、早秋桃和晚秋桃产量分别占8.89%、45.35%、33.41%和12.36%,伏桃和早秋桃是产量主体,但早秋桃的成产强度大。随着施N量增加,早秋桃和晚秋桃的纤维产量占比增加,而随着DPC用量增加则表现相反。(2) N肥用量和DPC用量均对纤维长度、整齐度、比强度和马克隆值有显著影响,但对纤维伸长率影响达不到显著水平。N1处理和D1处理的纤维品质综合表现最优,但D0处理马克隆值最佳。N肥与DPC用量互作对“四桃”的纤维比强度和马克隆值有显著影响,其中, N1D1处理“四桃”的比强度和马克隆值均表现最优,而N2D2处理“四桃”的比强度和马克隆值表现最差。此外,过量施N和过量喷施DPC均会升高马克隆值。(3)“四桃”的纤维品质存在差异。伏前桃的纤维品质除马克隆值最优外,其纤维长度、整齐度和比强度最差;伏桃和早秋桃的纤维长度、整齐度和比强度最优,但马克隆值表现最差,伸长率居中;晚秋桃的伸长率最优,其余品质指标均居中。研究结果丰富了“四桃”产量和品质差异的相关理论,并为棉花合理施N和喷施DPC以及“四桃”纤维的合理利用提供了科学依据。
文摘Genetic diversity provides the foundation for crop improvement. Genetic variation and associations among Cotton Leaf Curl Disease (CLCuD), fiber and yield related traits were investigated in exotic lines of Gossypium arboreum L. in an experimental field at the Central Cotton Research Institute (CCRI), Multan, Pakistan during the crop season 2011-12. One hundred and nineteen (119) accessions imported from USA through the Pakistan and US “Cotton Productivity Enhancement Program” (CPEP), were evaluated in this study. Various statistical approaches including descriptive statistics, correlation and principal component analysis was performed to evaluate and identify desirable genotypes. Results revealed that seed cotton yield was significantly and positively correlated with boll weight and number of bolls plant-1. Similarly, plant height was also significantly correlated with sympodial branches, lint percentage and micronaire value. Lint percentage showed a highly significant and positive correlation with plant height, sympodial branches and micronaire value. With respect to fiber traits, negative and significant relationships were observed between the micronaire value (MIC) and fiber strength. CLCuD showed no relationship with any of the studied traits, as all the G. arboreum L. lines evaluated were scored resistant to CLCuD. Principal component analysis (PCA) showed that the first four out of 11 components contributed about 65.88% of the total variation having an eigen value greater than 1. Based on PCA, the genotypes GS-4, GS-9, GS-8, GS-55 and GS-50 could be utilized successfully in a future breeding program based on having the highest positive loading factor for staple length (0.135) in PC1 and seed cotton yield (0.625), number of bolls plant-1, boll weight, first sympodial nod, staple length and fiber strength in PC2 respectively.
文摘A new modification for the shear lag model is given and the expressions for the stiffness and yield Strength of short fiber metal matri×composite are derived. These expressions are then compared with our experimental data in a SiCw/Al-Li T6 composite and the published experimental data on different SiCw/Al T6 composites and also compared with the previous shear lag models and the other theoretical models.
