Characterization and screening of cotton(Gossypium hirsutum L.)germplasm for leafhopper(Amrasca biguttula biguttula(Ishida))resistance

Background Cotton(Gossypium hirsutum L.)is one of the most significant fibre and cash crops and plays an important role in Indian industrial and agricultural economies.However,over the years quantity and quality have been hampered by the pest leafhopper.Leafhopper alone has been shown to cause yield losses of up to 40%.In this study,screening and evaluation were performed to identify and categorize 100 cotton genotypes along with 5 checks as resistant,moderately resistant,sensitive and highly sensitive to leafhoppers.Results A total of hundred genotypes were evaluated along with five checks for leafhopper resistance.Based on the screening results,a total of 19 genotypes were resistant to leafhoppers,which was on par with the findings of the check KC 3.The contents of total soluble sugar,total soluble protein,and total free amino acids were significantly positively correlated with the mean grade,whereas total phenols content and trichome density were significantly negatively correlated with the susceptibility grade.However,based on screening and biochemical analysis,the genotypes KC 2,JR-23,Samaru-26-T,D 4,TCH 1728,RS 253,and B-61-1862 exhibited high resistance to leafhopper.Conclusion According to the findings of this study,choosing genotypes with high total phenolics content together with high trichome density and low contents of total soluble sugar,total soluble protein,and free amino acids may aid in the development of resistant genotypes.

Combining ability of Egyptian cotton(Gossypium barbadense L.)reveals genetic potential for improved yield and fiber quality

Background As the most widely cultivated fiber crop,cotton production depends on hybridization to unlock the yield potential of current varieties.A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits,such as high yield and fine fiber quality.In this study,the general combining ability(GCA)and specific combining ability(SCA)of yield and fiber quality of nine cotton parents(six lines and three testers)and eighteen F1 crosses produced using a line×tester mating design were analyzed.Results The results revealed significant effects of genotypes,parents,crosses,and interactions between parents and crosses for most of the studied traits.Moreover,the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes.The F1 hybrids of(Giza 90×Aust)×Giza 86,Uzbekistan 1×Giza 97,and Giza 96×Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics.Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield,while lint percentage showed the highest negative direct effect on seed cotton yield.Principal component analysis identified specific parents and hybrids associated with higher cotton yield,fiber quality,and other agronomic traits.Conclusion This study provides insights into identifying potential single-and three-way cross hybrids with superior cotton yield and fiber quality characteristics,laying a foundation for future research on improving fiber quality in cotton.

多环境下陆地棉(Gossypium hirsutum L.)重组自交系铃重与衣分性状的QTL分析

本研究利用以SGK9708为母本,0-153为父本构建的196个陆地棉重组自交系(F6:8)构建了包含186个标记,总长827.84cM,标记间平均距离4.45cM,覆盖棉花基因组18.6%的遗传连锁图谱,并对7个环境下的铃重和衣分性状进行QTL定位和上位性互作分析。利用两种分析软件(WinQTLcart2.5和QTLNetwork2.0)共同定位了多个环境下稳定表达的5个主效QTLs(qBW-1-1,qBW-1-2,qLP-2-1,qLP-2-2和qLP-4-2)。利用QTLNetwork2.0分别检测到4对铃重上位性互作QTLs和7对衣分上位性互作QTLs,以背景位点间的互作和加性效应位点与背景位点间的互作为主。除主效QTL外,上位性效应也是陆地棉铃重和衣分性状的重要遗传基础。本研究定位的5个主效QTLs为选择高铃重、高衣分品种的棉花分子标记辅助育种提供了重要依据。

A Novel Segregation Distortion in Intraspecific Population of Asian Cotton(Gossypium arboretum L.)Detected by Molecular Markers

The segregation ratio of markers in an F2 population derived from Rudongjijiaoyaguo （Rdjjyg） and Zhongmian971 （Zm971） was studied using 3 morphological markers, 20 SSR markers, and ll SRAP markers. Totally, 24 markers （77.42%） showed a distorted segregation and all of them skewed toward the female genotype, which was peculiar in recent cotton research. All the three types of SSR markers and SRAP marker showed distorted segregation, but the morphological markers （Purple stem, Okra leaf, and Red spot color） were normally segregated. This indicated that such a novel segregation distortion phenomenon resulted from interior genetic factors, The allele frequency and the distribution of different genotype frequencies in the F2 population were analyzed in codominant markers, to find out factors attributed to distorted segregation. Most of them implied distorted allele frequency, but it was normal genotype frequency, which showed that these markers were influenced at the gamete level.

Genetic variation in LBL1 contributes to depth of leaf blades lobes between cotton subspecies, Gossypium barbadense and Gossypium hirsutum

Leaf is a essential part of the plants for photosynthetic activities which mainly economize the resources for boll heath. Significant variations of leaf shapes across the Gossypium sp. considerably influence the infiltration of sunlight for photosynthesis. To understand the genetic variants and molecular processes underlying for cotton leaf shape, we used F2 population derived from upland cotton genotype P30A （shallow-lobed leaf） and sea-island cotton genotype ISR （deep-lobed leaf） to map leaf deep lobed phenotype controlling genes LBL1 and LBL2. Genetic analysis and localization results have unmasked the position and interaction between both loci of LBL1 and LBL2, and revealed the co-dominance impact of the genes in regulating depth of leaf blades lobes in cotton. LBL1 had been described as a main gene and member of transcription factor family leucine zipper （HD-ZIPI） from a class I homologous domain factor Gorai.OO2G244000. The qRT-PCR results elaborated the continuous change in expression level of LBL1 at different growth stages and leaf parts of cotton. Higher expression level was observed in mature large leaves followed by medium and young leaves respectively. For further confirmation, plants were tested from hormonal induction treatments, which explained that LBL 1 expression was influenced by hormonal signaling. Moreover, the highest expression level was detected in brassinolides （BR） treatment as compared to other hormones, and this hormone plays an important role in the process of leaf blade lobed formation.

Bioinformatics Analysis of PHYB Gene in Upland Cotton(Gossypium hirsutum)

[Objective] This study was conducted to clarify the biological information of PHYB genes in upland cotton （Gossypium hirsutum）. [Method] Two PHYB genes were identified from the genome database of allotetraploid cotton （G. hirsutum L. acc. TM-1）, and were found to be distributed on subgenomes A10 and D10. And then bioinformatic analysis on these two genes were performed. [Result] The PHYB genes of upland cotton had the same motifs and domains with the PHYB genes in other plant species, and even the number and location of the motifs and domains of these PHYB genes were consistent. The PHYB amino acid sequence alignment and the phylogenetic tree constructed based on PHYB amino acid sequence of these plant species indicated that the two PHYB genes in upland cotton had higher homology and closer evolutionary relationships with cocoa （Theobroma cacao）, but lower similarity to PHYB genes in monocotyledonous plants, such as rice （Oryza saitva） and corn （Zea mays）. The comparison of PHYB gene structure also revealed that plant PHYB gene was more conserved during evolution. The autophosphorylation of dozens of phosphorylation sites in upland cotton PHYB gene may be essential for the functions of phytochromes and plays a significant role in regulating phytochrome-mediated signal transduction pathways. [Conclusion] The results of this paper will provide a theoretical basis for the cloning and functional research of PHYB genes.

棉花(Gossypium hirsutum L.)原生质体培养的体细胞胚胎发生及植株再生

以陆地棉(G.hirsutum L.)3118、晋棉4号和柯字棉312等3个品种为材料,取种子无菌苗的下胚轴诱导愈伤组织,建立胚性细胞悬浮培养系。以2％纤维素酶Ono-zuka RS和0.1％离析软化酶Y-23组成的混合酶液,从细胞悬浮培养物游离出原生质体。用含低融点琼脂糖的K_3培养基包埋原生质体,采用园柱及薄层漂浮平板培养方式。3个品种的原生质体培养都得到了愈伤组织,其中晋棉4号和柯字棉312品种的愈伤组织转到低激素水平或无激素的MS-2培养基上诱导产生胚状体,胚状体在无激素的MS-1培养基上形成了植株。

棉属(Gossypium)种子蛋白质电泳图谱与种间关系

用SDS聚丙烯酰胺凝胶电泳(SDS-PAGE)法对棉属23个野生种及4个栽培种的10个品种进行了种子水溶性蛋白质分析。结果表明,种内的蛋白质电泳图谱基本一致,各染色体组则具有其特征的蛋白质图谱模式。B染色体组最接近棉属二倍休原始祖先。A染色体组及D染色体组的部分种起源于B染色体组。G.arboreum race sinense可能起源于G.herbaceum raced africanum。D染色体组具有两种不同的图谱模式,即D_β和D_ε模式,但D与B染色体组更接近。AD染色体组的(AD)_1,(AD)_2及(AD)_5图谱相似,推测它们具有共同的祖先,起源于A和D_β组的种间杂种的染色体加倍。G.australe和G.nelsonii具有同G.sturtianum和G.robinsonii相近的蛋白质图谱模式,其亲缘关系较近。

Genome-wide analysis of the WRKY transcription factor gene family in Gossypium raimondii and the expression of orthologs in cultivated tetraploid cotton

WRKY proteins are members of a family of transcription factors in higher plants that function in plant responses to various physiological processes.We identified 120 candidate WRKY genes from Gossypium raimondii with corresponding expressed sequence tags in at least one of four cotton species,Gossypium hirsutum,Gossypium barbadense,Gossypium arboreum,and G.raimondii.These WRKY members were anchored on 13 chromosomes in G.raimondii with uneven distribution.Phylogenetic analysis showed that WRKY candidate genes can be classified into three groups,with 20 members in group I,88 in group II,and 12 in group III.The88 genes in group II were further classified into five subgroups,groups IIa–e,containing 7,16,37,15,and 13 members,respectively.We characterized diversity in amino acid residues in the WRKY domain and/or other zinc finger motif regions in the WRKY proteins.The expression patterns of WRKY genes revealed their important roles in diverse functions in cotton developmental stages of vegetative and reproductive growth and stress response.Structural and expression analyses show that WRKY proteins are a class of important regulators of growth and development and play key roles in response to stresses in cotton.

棉属（Gossypiumspp．）种子SOD酶的凝胶电泳图谱与种间关系

棉属２９个野生种和４个栽培种４７份材料的种子ＳＯＤ同工酶的凝胶电泳图谱表明：①同一栽培种多数品种的谱带完全一致；②同一染色体组内种间迁移率相同的酶带较多，其中Ｄ染色体组内差异最小，Ｃ染色体组内差异最大。根据研究结果推测：①Ｂ染色体组可能是棉属中最原始的类群，Ａ、Ｅ染色体组由Ｂ染色体组分别进化而来；②雷蒙德氏棉和瑟伯氏棉可能分别为阔叶型和披针叶型异源四倍体棉Ｄ染色体亚组的供体；③Ａ１２０可能属于棉属；④Ａ１１２与奈尔逊氏棉、澳洲棉的亲缘关系较近，与斯托提棉、鲁滨逊氏棉的关系较远。ＳＯＤ酶可以作为研究种间关系和分类的重要方法之一。

盐胁迫下棉属野生种旱地棉(Gossypium aridum)差异表达基因的cDNA-AFLP分析(英文)

以一个耐盐的二倍体野生种旱地棉和对盐敏感的陆地棉栽培种苏棉12号为材料，运用cDNA—AFLP技术，比较两个材料分别在盐胁迫前后的表达情况，获得了25个仅在旱地棉盐胁迫下特异表达的转录片段（TDF）。将这些片段进行电子克隆，延伸后的序列进行BLAST分析，结果显示23个转录片段推断的氨基酸序列与已知的蛋白同源，这些盐诱导表达的基因主要涉及离子转运、活性氧清除、细胞信号传导、细胞分裂、转录调节、膜保护、渗透调节等功能蛋白。从23个差异表达的转录片段中选择9个进行实时定量PCR（qRT—PCR）分析，结果表明这些基因在盐胁迫后表达显著增强，而且多数在12～24h达到高峰。这些cDNA克隆是开展棉花耐盐性分子基础研究的重要资源。

Screening of drought resistance indices and evaluation of drought resistance in cotton(Gossypium hirsutum L.)

Sixteen cotton cultivars widely planted in China were sowed under five different drought concentrations(0,2.5,5,7.5,and 10%)using PEG6000 to screen the indices of drought resistance identification and explore the drought resistance of different cotton cultivars.Eighteen physiological indices including root,stem,and leaf water contents(RWC,SWC,and LWC),net photosynthetic rate(Pn),the maximum photochemical quantum yield(Fv/Fm),the actual photochemical quantum yield(ΦPSII),non-photochemical quenching coefficient(NPQ),leaf water potential(LWP),osmotic potential(Ψs),leaf relative conductivity(REC),leaf proline content(Pro),leaf and root soluble protein contents(LSPC and RSPC),leaf and root malondialdehyde(MDA)contents(LMDA and RMDA),root superoxide dismutase,peroxidase,and catalase activities(RSOD,RPOD,and RCAT)were measured.Results indicated the 18 physiological indices can be converted into five or six independent comprehensive indices by principal component analysis,and nine typical indices(Fv/Fm,SWC,LWP,Pro,LMDA,RSPC,RMDA,RSOD,and RCAT)screened out by a stepwise regression method could be utilized to evaluate the drought resistance.Moreover,the 16 cotton cultivars were divided into four types:drought sensitive,drought weak sensitive,moderate drought resistant,and drought resistant types.The resistance ability of two selected cotton cultivars(drought resistant cultivar,Dexiamian 1;drought sensitive cultivar,Yuzaomian 9110)with contrasting drought sensitivities were further verified by pot experiment.Results showed that the responses of final cotton biomass,yield,and yield composition to drought were significantly different between the two cultivars.In conclusion,drought resistant cultivar Dexiamian 1 and drought sensitive cultivar Yuzaomian 9110 were screened through hydroponics experiment,which can be used as ideal experimental materials to study the mechanism of different cotton cultivars with contrasting drought sensitivities in response to drought stress.

基因枪介导的海岛棉(Gossypium barbadense L.)茎尖遗传转化体系的建立

以新疆海岛棉品种新海13号的茎尖为转化受体,采用基因枪介导法,研究DNA包裹浓度、微载体种类、前渗处理时间、轰击条件、筛选方法等对茎尖转化的影响,建立了基因枪法介导的海岛棉茎尖转化体系。研究结果表明,采用1.5μg·μL-1的质粒DNA包裹1.0μm金粉微载体,前渗处理12 h,轰击压力为7.584 MPa(1100 psi),轰击距离为6 cm,后渗处理16 h,恢复处理24 h,在120 mg·L-1卡那霉素浓度下直接筛选35 d。在添加4g·L-1活性炭粒的生根培养基中诱导抗性幼苗生根,获得抗性再生植株。通过PCR和RT-PCR检测,共得到5株转抗除草剂基因EPSPS的阳性植株。该研究体系的建立为海岛棉的遗传转化奠定了基础,为海岛棉的育种工作提供了材料。

施氮量对不同开花期棉(Gossypium hirsutum L．)铃纤维细度和成熟度形成的影响

为兼顾试验的重复性和生态区域性,选用高品质棉(科棉1号)和常规棉(美棉33B)品种为材料,于2005年分别在江苏南京(118°50'E,32°02'N,长江流域下游棉区)和江苏徐州(117°11'E,34°15'N,黄河流域黄淮棉区)设置施氮量(低氮N 0 kg/hm2;适氮N 240 kg/hm2;高氮N 480 kg/hm2)试验,研究施氮量对不同开花期棉铃纤维细度、成熟度和马克隆值形成的影响。结果表明,(1)施氮量显著影响棉纤维细度、成熟度和马克隆值的形成过程,但三者在不同开花期对氮素水平的响应不同,施氮量与开花期对棉纤维细度、成熟度和马克隆值的形成存在互作效应。8月10日前开花的棉铃,铃期[花后0～50 d(DPA)]日均温在23.3℃以上,纤维细度、马克隆值以N 0 kg/hm2施氮量下最大,棉纤维马克隆值与纤维细度的相关性较大;8月25日开花的棉铃(铃期日均温在20.8～23.3℃之间),纤维成熟度、马克隆值以N 240 kg/hm2施氮量下最大;9月10日开花棉铃(铃期日均温低于20.8℃),纤维细度、成熟度和马克隆值均以N 480 kg/hm2最大,棉纤维马克隆值与纤维成熟度的相关性增强。(2)影响不同开花期间纤维细度、成熟度和马克隆值的主要因素是铃期日均温;最终纤维细度、成熟度和马克隆值在不同施氮量之间的变异与不同开花期(铃期日均温不同)间的变异比较,前者显著小于后者。综上,因开花期不同而形成的铃期日均温是决定纤维细度、成熟度和马克隆值的最重要因素,施氮量可通过对位叶叶氮浓度NA影响棉纤维细度、成熟度和马克隆值的形成过程,增加施氮量可减小上述指标在不同开花期间的差异。

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 13 linkage groups. The map spans 2,508.71 cM with an average distance of 9.4 cM between adjacent loci. A population containing 176 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.

Ameliorative effects of potassium on drought-induced decreases in fiber length of cotton(Gossypium hirsutum L.) are associated with osmolyte dynamics during fiber development

Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluated the effect of K on fiber elongation using two cotton cultivars,Simian 3 and Siza 3,grown in well-watered and drought-stressed conditions.Potassium fertilizer(K2O)was applied 0,150,or 300 kg ha?1 in each growing condition.Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax,mmday?1).The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax.At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP)and increased K+and malate contents at all K rates,relative to well-watered conditions,which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC),V-ATPase,PPase,and PM H+-ATPase in cotton fiber.However,the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition.Compared with control without K,K application decreased OP and increased the accumulation of osmolytes(K+,malate and soluble sugar)as well as the activities of related enzymes in fiber irrespective of water treatments.Moreover,K application increased osmotic adjustment during drought,and improved the contribution of K+and malate to OP,especially under drought stress.This study showed that drought decreased fiber length by reducing Vmax,and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.

棉属(Gossypium)野生种与栽培种杂交杂种F_1遗传性状及细胞学研究

研究了栽培种陆地棉(G.hirsutum)与异常棉(G.anomalum)、斯特提棉(G.sturtianum)、雷蒙德氏棉(G.raimondii)、辣根棉(G.armourianum)、司笃克氏棉(G.stocksii)杂交杂种 F_1的遗传性状及减数分裂过程中的染色体行为。结果表明,杂种 F_1植株不育,在茎、叶形态、茸毛、颜色、花冠大小、颜色,基部有红心等表现了野生亲本的特性。各杂种减数分裂过程中产生少数二价体或极少数的三价、四价体,大部分为单价体。后期形成较多的异常多分体,而后产生大量的大小不一致的小孢子,而且绝大部分无生活力。还分析了母本陆地棉与5个野生种父本的亲缘关系。

Relationship between plant canopy characteristics and photosynthetic productivity in diverse cultivars of cotton(Gossypium hirsutum L.)

Genotype and plant type affect photosynthetic production by changing the canopy structure in crops.To analyze the mechanism of action of heterosis and plant type on canopy structure in cotton(Gossypium hirsutum L.),we had selected two cotton hybrids(Shiza 2,Xinluzao 43) and two conventional varieties(Xinluzao 13,Xinluzao 33) with different plant types in this experiment.We studied canopy characteristics and their correlation with photosynthesis in populations of different genotypes and plant types during yield formation in Xinjiang,China.Canopy characteristics including leaf area index(LAI),mean foliage tilt angle(MTA),canopy openness(DIFN),and chlorophyll relative content(SPAD).The results showed that LAI and SPAD peak values were higher and their peak values arrived later,and the adjustment capacity of MTA during the flowering and boll-forming stages was stronger in Xinluzao 43,with the normal-leaf,pagoda plant type,than these values in other varieties.DIFN of Xinluzao 43 remained between0.09 and 0.12 during the flowering and boll-forming stages,but was lower than that in the other varieties during the boll-opening stage.Thus,these characteristics of Xinluzao 43 were helpful for optimizing the light environment and maximizing light interception,thereby increasing photosynthetic capability.The photosynthetic rate and photosynthetic area were thus affected by cotton genotype as changes in the adjustment range of MTA,increases in peak values of LAI and SPAD,and extension of the functional stage of leaves.Available photosynthetic area and canopy light environment were affected by cotton plant type as changes in MTA and DIFN.Heterosis expression and plant type development were coordinated during different growth stages,the key to optimizing the canopy structure and further increasing yield.

中棉所12(Gossypium hirsutum C.V.Zhongmian 12)体细胞胚发生及植株再生

通过对不同外植体的研究，发现幼胚下胚轴是理想的外植体材料；２，４Ｄ和ＺＴ是中棉所１２体细胞胚发生的关键植物生长调节物。从愈伤组织诱导到大量再生植株只需４个月左右的时间。

Somatic Embryogenesis and Plant Regeneration from Two Recalcitrant Genotypes of Gossypium hirsutum L.

An improved protocol has been developed for somatic embryogenesis and plant regeneration of recalcitrant cotton cultivars. High callus frequencies and embryogenic tissue were developed in MSB medium supplemented with gradient concentrations of KT and 2,4-D, their concentration decreasing from 0.1 to 0.01 mg·L^-1. Somatic embryos were successfully incubated in 1/2 macronutrient MSB suspension supplemented with 0.5 g· L^-1 glutamine and 0.5 g·L^-1 asparagine. Decrease in macronutrient concentration of MSB significantly alleviated browning and was beneficial to suspension cells. Transformation of somatic embryos into plants was induced in MSB medium supplemented with 3% sucrose, 0.5 g·L^-1 glutamine, 0.5 g·L^-1 asparagine, and 6.0 g·L^-1 agar. The effect of sucrose as carbohydrate was better than that of glucose for plant germination. Using this protocol, regenerated plantlets from the CCRI521 and Zhongzhi86-6 reached to as much as 19.6 and 18.5% somatic embryos, respectively.