A comparative study of seed yield parameters in Arabidopsis thaliana mutants and transgenics

Because seed yield is the major factor determining the commercial success of grain crop cultivars, there is a large interest to obtain more understanding of the genetic factors underlying this trait. Despite many studies, mainly in the model plant Arabidopsis thaliana, have reported transgenes and mutants with effects on seed number and/or seed size, knowledge about seed yield parameters remains fragmented. This study investigated the effect of 46 genes, either in gain- and/or loss-of-function situations, with a total of 64 Arabidopsis lines being examined for seed phenotypes such as seed size, seed number per silique, number of inflorescences, number of branches on the main inflorescence and number of siliques. Sixteen of the 46 genes, examined in 14 Arabidopsis lines, were reported earlier to directly affect in seed size and/or seed number or to indirectly affect seed yield by their involvement in biomass production. Other genes involved in vegetative growth, flower or inflorescence development or cell division were hypothesized to potentially affect the final seed size and seed number. Analysis of this comprehensive data set shows that of the 14 lines previously described to be affected in seed size or seed number, only nine showed a comparable effect. Overall, this study provides the community with a useful resource for identifying genes with effects on seed yield and candidate genes underlying seed QTL. In addition, this study highlights the need for more thorough analysis of genes affecting seed yield.     

播期对内蒙古西部荒漠区棉花产量、品质及养分吸收利用的影响

于2014—2015年在内蒙古自治区阿拉善盟阿拉善左旗内蒙古棉花综合实验站设置大田试验,以‘中棉所50’为材料,采用“一膜三管六行”机采棉配套栽培技术种植,研究播期(4月20日、4月30日和5月10日)对棉花产量、品质及养分吸收的影响.结果表明: 随着播期推迟,棉花生育时期推迟,生育期缩短,铃期日均温降低,收获密度增加;播期显著影响棉株干物质累积、养分吸收与分配,以及产量和品质形成,4月30日播种条件下,棉株干物质和养分在经济器官中的分配比例、养分总积累量及养分的皮棉生产效率较高,籽棉和皮棉产量最高,达6505.9和2660.9 kg·hm^-2,且纤维品质较优;4月20日播期下,收获密度、生物量和养分累积量最低,虽然生物量和养分经济系数最高,但最终籽棉和皮棉产量仍较4月30日播期降低10.9%～14.0%和11.1%～14.2%;5月10日播期,虽然可以避开种子萌发期低温冷害,但棉铃发育期日均温偏低,尽管生物量和养分累积量最高,但是生物量和养分经济系数、养分的皮棉生产效率最低,最终籽棉和皮棉产量较4月30日播期降低32.5%～34.7%和35.9%～36.2%,且纤维品质最差.综合分析, 4月30日左右为内蒙古西部荒漠旱区棉花种植的最佳播期.     

内蒙古西部旱区机采棉膜下滴灌水氮耦合效应

为探明内蒙古西部旱区机采棉膜下滴灌水氮耦合对棉花生长发育、产量、品质,以及水分与氮素利用效率的影响,在内蒙古阿拉善盟阿拉善左旗,设置3种灌溉定额(216、288、360 mm,分别记为W₁、W₂、W₃)和3种施氮水平(127.5、195、262.5 kg·hm^-2,分别记为N₁、N₂、N₃)的完全组合处理,进行了大田棉花膜下滴灌试验.结果表明: 水分是膜下滴灌棉花生长的决定因素,增加灌水量可以促进棉花株高增加,提高棉花各部分干物质积累量,但降低生殖器官与地上部干物质比例.W₃处理单株成铃数较W₁和W₂分别提高25.4%和17.5%,单铃质量分别降低5.8%和4.6%,籽棉产量分别增加18.1%和11.9%;单株成铃数提高是籽棉产量增加的主要因素.水氮调控对籽棉产量的互作效应显著,W₁与W₂灌水量下N₁处理籽棉产量最高;W₃灌水量下N₂处理较N₁、N₃籽棉产量分别增加8.5%和31.9%.水氮调控对纤维品质整体无显著影响.W₁N₁处理水分利用效率最高,为1.37 kg·m^-3,与W₃N₂处理差异不显著;W₃N₁处理氮肥偏生产力最高,为51.35 kg·kg^-1.在本试验条件下,灌水增产效应显著,施氮则在水分充足条件下对籽棉产量形成有促进作用.其中,灌水360 mm、施氮195 kg·hm^-2处理显著促进地上部干物质积累,籽棉产量最高,水分利用效率和氮肥偏生产力分别达1.30 kg·m^-3和36.41 kg·kg^-1,节水增产效果显著,是内蒙西部旱区较理想的机采棉水氮调控模式.     

Developing Fiber Specific Promoter-Reporter Transgenic Lines to Study the Effect of Abiotic Stresses on Fiber Development in Cotton

Cotton is one of the most important cash crops in US agricultural industry. Environmental stresses, such as drought, high temperature and combination of both, not only reduce the overall growth of cotton plants, but also greatly decrease cotton lint yield and fiber quality. The impact of environmental stresses on fiber development is poorly understood due to technical difficulties associated with the study of developing fiber tissues and lack of genetic materials to study fiber development. To address this important question and provide the need for scientific community, we have generated transgenic cotton lines harboring cotton fiber specific promoter (CFSP)-reporter constructs from six cotton fiber specific genes (Expansin, E6, Rac13, CelA1, LTP, and Fb late), representing genes that are expressed at different stages of fiber development. Individual CFSP::GUS or CFSP::GFP construct was introduced into Coker 312 via Agrobacterium mediated transformation. Transgenic cotton lines were evaluated phenotypically and screened for the presence of selectable marker, reporter gene expression, and insertion numbers. Quantitative analysis showed that the patterns of GUS reporter gene activity during fiber development in transgenic cotton lines were similar to those of the native genes. Greenhouse drought and heat stress study showed a correlation between the decrease in promoter activities and decrease in fiber length, increase in micronaire and changes in other fiber quality traits in transgenic lines grown under stressed condition. These newly developed materials provide new molecular tools for studying the effects of abiotic stresses on fiber development and may be used in study of cotton fiber development genes and eventually in the genetic manipulation of fiber quality.     

转基因抗虫棉的产量、品质及抗虫性比较研究

对36个转基因抗虫棉品种(品系)进行试验,比较了它们的产量、抗棉铃虫和红铃虫特性以及纤维品质之间的差异,并进行综合评价。在不打药的情况下,筛选出252等13份皮棉产量比鄂抗9号显著提高、抗棉铃虫和红铃虫的种质材料,其纤维品质综合性状表现一般。     

喷灌条件下耕作方式和亏缺灌溉对麦后移栽棉产量和水分利用的影响

探明耕作方式和亏缺灌溉对麦后移栽棉产量和水分利用的效应,对于建立麦后移栽棉的适宜耕作方式及灌溉制度十分重要.在大田条件下设置了翻耕和免耕2种耕作方式(灌水定额均为45 mm)及相应减小50％灌水定额的亏缺灌溉,分析了不同耕作方式和亏缺灌溉对棉花耗水规律、籽棉产量、水分利用效率和纤维品质的影响.结果表明:与翻耕相比,免耕减少了棉田20.3％的棵间土壤蒸发;不论何种耕作方式,亏缺灌溉在不影响棉花产量和纤维品质的同时,有效降低了耗水量,提高了水分利用效率.在喷灌条件下,灌水定额为22.5 mm的免耕耕作方式,不仅可有效降低麦后移栽棉田间无效棵间土壤蒸发,还可实现节水、优质、高产的有效统一.     

Genomes for jeans: cotton genomics for engineering superior fiber

Twenty years ago, scientists predicted that better understanding of fiber development would lead to novel ways to engineer superior cotton fiber. Advances in genetic resources, DNA markers, DNA sequence information, and gene expression data have indeed provided new insights into fiber initiation, elongation and maturation. Many exciting applications of this knowledge offer the potential to select better cotton genotypes more effectively in mainstream breeding programs or engineer genotypes with improved agronomic and/or quality traits. Here, we discuss recent progress in understanding genes involved in fiber development, and their regulation and manipulation to engineer improved fibers. Better understanding of quantitative trait loci/gene interactions that influence fiber quality and yield may help to tailor superior cotton genotypes to diverse environments.     

Expression of genes associated with carbohydrate metabolism in cotton stems and roots

Background  

Cotton (Gossypium hirsutum L) is an important crop worldwide that provides fiber for the textile industry. Cotton is a perennial plant that stores starch in stems and roots to provide carbohydrates for growth in subsequent seasons. Domesticated cotton makes these reserves available to developing seeds which impacts seed yield. The goals of these analyses were to identify genes and physiological pathways that establish cotton stems and roots as physiological sinks and investigate the role these pathways play in cotton development during seed set.     

苗期遮荫对棉花产量与品质形成的影响

为揭示棉麦两熟共生期遮荫对棉花产量与品质形成的影响。在棉花苗期利用模拟棉麦两熟共生期遮荫的方法进行了研究。结果表明,遮荫对棉铃形成的影响因果枝,果节部位而异,遮荫有利于棉株下（1-3果枝）,中（4-6果枝）,上（7-9果枝）部果枝内围（1-2果节）铃的形成,对外围（≥3果节）尤其顶部果枝（≥10果枝）外围铃形成不利,从而决定铃重也随果枝,果节部位相应地变化,但遮荫对单株平均铃重的影响畔 小,变遮荫棉花籽棉产量而论,下,中部果枝的内围铃籽棉产量高于常规棉,在上,顶部果枝则相反,各部位果枝外围铃的籽棉产量均低于常规棉,遮荫棉花内,外围铃分布为1：0.36(常规棉为1：0.58),产量分布为1：0.42(常规棉为1：0.72)。苗期遮荫对棉纤维,棉籽品质性状的影响也主要在顶部果枝和上部果枝外围铃,综合分析遮荫棉花产量与品质的形成,棉花苗期耐遮荫性品种间存在差异。在本研究中以中9418耐遮荫性最强,中棉所19和春矮早次之。     

QTL mapping in A-genome diploid Asiatic cotton and their congruence analysis with AD-genome tetraploid cotton in genus Gossypium

Asiatic cotton(Gossypium arboreum L.) is an Old World cultivated cotton species.The sinense race was planted extensively in China.Due to the advances in spinning technology during the last century,the species was replaced by the New World allotetraploid cotton G.hirsutum L.Gossypium arboreum is still grown in India and Pakistan and also used as an elite in current cotton breeding programs.In addition,G.arboreum serves as a model for genomic research in Gossypium.In the present study,we generated an A-genome diploid cotton intraspecific genetic map including 264 SSR loci with three morphological markers mapped to 1 3 linkage groups.The map spans 2,508.71 cM with an average distance of 9.4 cM between adjacent loci.A population containing 1 76 F2:3 families was used to perform quantitative trait loci(QTL)mapping for 17 phenotypes using Multiple QTL Model(MQM)of MapQTL ver 5.0.Overall,108 QTLs were detected on 13 chromosomes.Thirty-one QTLs for yield and its components were detected in the F2 population.Forty-one QTLs for yield and its components were detected in the F2:3 families with a total of 43 QTLs for fiber qualities.Two QTLs for seed cotton weight/plant and lint index and three QTLs for seed index were consistently detected both in F2 and F2:3.Most QTLs for fiber qualities and yields were located at the same interval or neighboring intervals.These results indicated that the negative correlation between fiber qualities and yield traits may result from either pleiotropic effect of one gene or linkage effects of multiple closely linked genes.     

施氮量和种植密度对东北特早熟棉区棉铃生物量和氮素累积的影响

以辽棉19号和美棉33B为材料,研究了不同施氮量(0、240、480 kg ·hm-2)和不同种植密度(75000、97500、120000 plants·hm-2)对东北特早熟棉区棉花棉铃生物量和氮素累积特征的影响.结果表明： 棉花单铃、棉籽和纤维的生物量及其氮素累积随棉花生育进程的动态变化均符合“S”型曲线,种植密度和施氮量可以显著影响棉铃各部分生物量和氮素累积的动态特征,以及棉花产量与品质;在施氮量240 kg·hm-2和种植密度97500 plants·hm-2处理下,单铃、棉籽和纤维的生物量均达到最大,生物量和氮素累积的快速累积起始时间和终止时间较早但持续时间较短,生物量快速累积速率最大,生物量和氮素在铃壳中的分配系数最低,在棉籽和纤维中分配系数最高.     

Influence of Nezara viridula feeding on cotton yield, fiber quality, and seed germination

The influence of southern green stink bug, Nezara viridula (L.), adults (males and females) and fourth to fifth instars on cotton, Gossypium hirsutum L., boll abscission, seedcotton yield, fiber quality, and seed viability was evaluated in field studies conducted during 2004 and 2005. Cotton bolls representing several age classes ranging from 0-600 heat units were individually infested with a specific gender or life stage of southern green stink bug. Adults and nymphs induced abscission of bolls that accumulated 0-280 heat units after anthesis. Seedcotton yield was significantly lower in bolls infested with adults (males and females) and late instars through approximately 500 heat units after anthesis. Southern green stink bug feeding on bolls significantly affected the physical fiber properties of micronaire (measure of fiber fineness or maturity), strength, uniformity, and fiber length. Discolored cotton lint in the stink bug-infested bolls was more common than in noninfested bolls. Seed germination and development of normal seedlings for seed harvested from stink bug-infested bolls that accumulated < or =500 heat units beyond anthesis were significantly lower compared with noninfested bolls. No significant differences in boll abscission, yield, fiber quality, and seed germination were detected between southern green stink bug males and females or between adults and fourth to fifth instars.     

Yield and size of oyster mushroom grown on rice/wheat straw basal substrate supplemented with cotton seed hull

Oyster mushroom (Pleurotus ostreatus) was cultivated on rice straw basal substrate, wheat straw basal substrate, cotton seed hull basal substrate, and wheat straw or rice straw supplemented with different proportions (15%, 30%, and 45% in rice straw substrate, 20%, 30%, and 40% in wheat straw substrate) of cotton seed hull to find a cost effective substrate. The effect of autoclaved sterilized and non-sterilized substrate on growth and yield of oyster mushroom was also examined. Results indicated that for both sterilized substrate and non-sterilized substrate, oyster mushroom on rice straw and wheat basal substrate have faster mycelial growth rate, comparatively poor surface mycelial density, shorter total colonization period and days from bag opening to primordia formation, lower yield and biological efficiency, lower mushroom weight, longer stipe length and smaller cap diameter than that on cotton seed hull basal substrate. The addition of cotton seed hull to rice straw and wheat straw substrate slowed spawn running, primordial development and fruit body formation. However, increasing the amount of cotton seed hull can increase the uniformity and white of mycelium, yield and biological efficiency, and increase mushroom weight, enlarge cap diameter and shorten stipe length. Compared to the sterilized substrate, the non-sterilized substrate had comparatively higher mycelial growth rate, shorter total colonization period and days from bag opening to primordia formation. However, the non-sterilized substrate did not gave significantly higher mushroom yield and biological efficiency than the sterilized substrate, but some undesirable characteristics, i.e. smaller mushroom cap diameter and relatively long stipe length.