Analysis of the Fiber Quality of Upland Cotton in China from 2005 to 2007

Upper-half-mean length(Len),uniformity index(UI),breaking tenacity(Str),and micronaire value(Mic) are the key quality parameters of cotton fiber.In this study,182 upland cotton

Genetic dissection and origin of pleiotropic loci underlying multilevel fiber quality traits in upland cotton(Gossypium hirsutum L.)

Cotton fiber quality is a persistent concern that determines planting benefits and the quality of finished textile products.However,the limitations of measurement instruments have hindered the accurate evaluation of some important fiber characteristics such as fiber maturity,fineness,and neps,which in turn has impeded the genetic improvement and industrial utilization of cotton fiber.Here,12 single fiber quality traits were measured using Advanced Fiber Information System(AFIS)equipment among 383 accessions of upland cotton(Gossypium hirsutum L.).In addition,eight conventional fiber quality traits were assessed by the High Volume Instrument(HVI)System.Genome-wide association study(GWAS),linkage disequilibrium(LD)block genotyping and functional identification were conducted sequentially to uncover the associated elite loci and candidate genes of fiber quality traits.As a result,the previously reported pleiotropic locus FL_D11 regulating fiber length-related traits was identified in this study.More importantly,three novel pleiotropic loci(FM_A03,FF_A05,and FN_A07)regulating fiber maturity,fineness and neps,respectively,were detected based on AFIS traits.Numerous highly promising candidate genes were screened out by integrating RNA-seq and qRT-PCR analyses,including the reported GhKRP6 for fiber length,the newly identified GhMAP8 for maturity and GhDFR for fineness.The origin and evolutionary analysis of pleiotropic loci indicated that the selection pressure on FL_D11,FM_A03 and FF_A05 increased as the breeding period approached the present and the origins of FM_A03 and FF_A05 were traced back to cotton landraces.These findings reveal the genetic basis underlying fiber quality and provide insight into the genetic improvement and textile utilization of fiber in G.hirsutum.

Transcriptome and QTL analyses reveal candidate genes for fiber quality in Upland cotton

With increasing demand for high-quality cotton,it is desirable to identify genes involved in fiber development for molecular improvement of cotton.In this study,780 differentially expressed genes(DEGs)were identified in developing fibers at 10 days post-anthesis(DPA)in Gossypium hirsutum acc.DH962 and G.hirsutum cv.Jimian 5 using RNA-seq.Of 15 stable QTL for fiber quality identified in the same two parents in previous studies,4,3,6,1,and 1 QTL were associated with fiber length(FL),fiber strength(FS),micronaire(MIC),fiber elongation(FE)and fiber length uniformity ratio(FU),respectively.Integration of DEGs and QTL allowed the identification of 31 genes in 9 QTL regions,of which 25 were highly expressed in fibers based on the transcriptome datasets and 9 were preferentially expressed in different stages of fiber development.Gh_A01G0453(GhDTX19),Gh_D07G1581 and Gh_D04G0942 were expressed specifically in 5 and 10 DPA fibers,with Gh_D04G0942 showing low expression in other tissues except pistil.Gh_D07G1799(GhGAUT9),Gh_D11G0326(GhVPS29),Gh_D11G0333(GhTCP14),and Gh_D11G0334(GhNRP2)were preferentially expressed in 5 or 10 DPA fibers;Gh_A01G0397(GhABCG10)and Gh_D07G1744 were expressed specifically in 20 and 25 DPA fibers.These results suggest candidate genes for molecular improvement of cotton fiber quality.

QTL and genetic analysis controlling fiber quality traits using paternal backcross population in upland cotton

Background:Genetic improvement in fiber quality is one of the main challenges for cotton breeders.Quantitative trait loci(QTL)mapping provides a powerful approach to dissect the molecular mechanism in fiber quality traits.In present study,F14 recombinant inbred line(RIL)population was backcrossed to paternal parent for a paternal backcross(BC/P)population,deriving from one upland cotton hybrid.Three repetitive BC/P field trials and one maternal backcross(BC/M)field trial were performed including both two BC populations and the original RIL population.Results:In total,24 novel QTLs are detected for fiber quality traits and among which 13 QTLs validated previous results.Thirty-five QTLs in BC/P populations explain 5.01%–22.09%of phenotype variation(PV).Among the 35 QTLs,23 QTLs are detected in BC/P population alone.Present study provides novel alleles of male parent for fiber quality traits with positive genetic effects.Particularly,qFS-Chr3–1 explains 22.09%of PV in BC/P population,which increaseds 0.48 cN·tex−1 for fiber strength.A total of 7,2,8,2 and 6 QTLs explain over 10.00%of PV for fiber length,fiber uniformity,fiber strength,fiber elongation and fiber micronaire,respectively.In RIL population,six common QTLs are detected in more than one environment:qFL-Chr1–2,qFS-Chr5–1,qFS-Chr9–1,qFS-Chr21–1,qFM-Chr9–1 and qFM-Chr9–2.Two common QTLs of qFE-Chr2–2(TMB2386-SWU12343)and qFM-Chr9–1(NAU2873-CGR6771)explain 22.42%and 21.91%of PV.The region between NAU4034 and TMB1296 harbor 30 genes(379 kb)in A05 and 42 genes(49 kb)in D05 for fiber length along the QTL qFL-Chr5–1 in BC/P population,respectively.In addition,a total of 142 and 46 epistatic QTLs and QTL×environments(E-QTLs and QQEs)are identified in recombinant inbred lines in paternal backcross(RIL-P)and paternal backcross(BC/P)populations,respectively.Conclusions:The present studies provide informative basis for improving cotton fiber quality in different populations.

QTL mapping for fiber quality and yieldrelated traits across multiple generations in segregating population of CCRI 70

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.

QTL mapping of agronomic and economic traits for four F_(2)populations of upland cotton

Background:Upland cotton(Gossypium hirsutum)accounts for more than 90%of the annual world cotton output because of its high yield potential.However,yield and fiber quality traits often show negative correlations.We constructed four F_(2)populations of upland cotton,using two normal lines(4133B and SGK9708)with high yield potential but moderate fiber quality and two introgression lines(Suyuan04–3 and J02–247)with superior fiber quality,and used them to investigate the genetic basis underlying complex traits such as yield and fiber quality in upland cotton.We also phenotyped eight agronomic and economic traits and mapped quantitative trait loci(QTLs).Results:Extensive phenotype variations and transgressive segregation were found across the segregation populations.We constructed four genetic maps of 585.97 centiMorgan(cM),752.45 cM,752.45 cM,and 1163.66 cM,one for each of the four F_(2)populations.Fifty QTLs were identified across the four populations(7 for plant height,27 for fiber quality and 16 for yield).The same QTLs were identified in different populations,including qBW4 and qBW2,which were linked to a common simple sequence repeat(SSR)marker,NAU1255.A QTL cluster containing eight QTLs for six different traits was characterized on linkage group 9 of the 4133B×Suyuan04–3 population.Conclusions:These findings will provide insights into the genetic basis of simultaneous improvement of yield and fiber quality in upland cotton breeding.

Identification and expression analysis of Tubulin gene family in upland cotton

Background:Cott on fibers are single-celled exte nsions of the seed epidermis,a model tissue for studying cytoskeleton.Tubulin genes play a critical role in synthesizing the microtubules(MT)as a core element of the cytoskeleton.However,there is a lack of studies concerning the systematic characterization of the tubulin gene family in cotton.Therefore,the identification and portrayal of G.hirsutum tubulin genes can provide key targets for molecular manipulation in cotton breeding.Result:In this study,we investigated all tubulin genes from different plant species and identified 98 tubulin genes in G.hirsutum.Phylogenetic an a lysis showed that tubulin family genes were classified into three subfamilies.The protein motifs and gene structure ofβ-tubulin genes are more conserved compared withγ-tubulin genes.Most tubulin genes are located at the proximate ends of the chromosomes.Spatiotemporal expression pattern by transcriptome and qRT-PCR analysis revealed that 12α-tubulin andβ-tubulin genes are specifically expressed during different fiber development stages.However,Gh.A03G027200,Gh.D03G 169300,and Gh.A1lG258900 had differential expression patterns at distinct stages of fiber development in varieties JO2508 and ZRI015.Conclusion:In this study,the evol ut io nary an alysis showed that the tubulin genes were divided into three clades.The genetic structures and molecular functions were highly con served in different plants.Three candidate genes,Gh.A03G027200f Gh.D03G169300,and Gh.A11G258900 may play a key role during fiber development complementing fiber length and strength.

Analysis on the Production Advantages of USA Pima Extra Long Staple Cotton

This paper defines the following advantages of ELS （Extra Long Staple） also known as Pima cotton planted in the United States： first, the only variety which is concentrated in the planting area with good soil moisture and fertilizer retention performances and abundant light and heat resources; second; advanced and practi- cal material equipment and technology; third; high yield and good quality, significant planting scale benefit; fourth, feasible and reliable modernized intensive farm man- agement mode with large-scale agricultural machinery operation; fifth, high-efficient social services and policy support system, as well as reasonable planting layout, good brand influence, synchronization of high yield and good quality with large-scale benefits. Although the production capability of Pima cotton in the United States is considered to be the largest and most powerful country in the world, compared with the ELS production in China, both have their own advantages and characteristics. Therefore, it is suggested that by using the ELS production experience ol the Unit- ed Stages for reference, China should make use of the modern breeding technJques to accelerate the modification of synthetic genetic features of ELS variety, try its best to breed the ELS variety which is suitable for mechanical plucking as soon as possible, actively develop new technology to simplify the whole cost saving cultiva- tion, reform ELS production organization, vigorously develop the social service sys- tem, and adjust and optimize the ELS industry support policies, so as to fundamen- tally improve the competitiveness of China＇s ELS in international market.

Phenotypic plasticity and genetic variation of cotton yield and its related traits under water-limited conditions

Global warming is limiting availability of water resources in arid and semi-arid regions,and so understanding water use efficiency(WUE)is increasingly important for agricultural production in those areas.As China is the largest cotton producing area,the problem of balancing WUE and efficient cotton production is a major issue.In this study,we used a natural population of 517 Upland cotton accessions to conduct a water-controlled trial in south and north of Xinjiang over two years.A total of 18 traits including agronomic traits,fiber yield indices and fiber quality indices,were investigated for broad-sense heritability and coefficient of variation.Appropriate water limitation was found to promote the establishment of favorable agronomic traits in cotton,associated with an increased cotton yield of 8.46%in Xinjiang,at the expense of a certain degree of fiber quality,such as decreased fiber length and an over-higher micronaire value.We detected 33 QTL related to response to water limitation using a drought resistance coefficient(DRC),and 6 QTL were found using a comprehensive indicator of CIDT(comprehensive index of drought tolerance)at the genetic level by integrating resequencing data.Two novel QTL-hotspots including six differentially expressed genes(DEGs)were further identified related to the drought response of cotton.These findings not only suggested a new approach to irrigation of cotton fields in Xinjiang,but also provided abundant genetic evidence for genetic breeders to study drought improvement of crops.

Sequencing of the Cultivated Tetraploid Cotton Genome-Gossypium hirsutum

Cotton is an important cash crop in the world,and it plays an irreplaceable role in China's national economy.Cultivated upland cotton(Gossypium hirsutum L.) represents 95% of the world's cotton production,but it has a complex allotetraploid genome that contains at least 30000 genes in 2500

陆地棉抗虫与抗草甘膦基因的分子聚合及经济性状相关分析

培育抗棉铃虫兼抗草甘膦的棉花,可以同步提高品种的抗虫与抗除草剂能力,降低植棉的除虫、除草用工成本,提升植棉综合经济效益。本研究利用自育的高产优质陆地棉品系、国产转Bt基因抗虫棉品系以及转GR79+GAT基因的抗草甘膦陆地棉品系为杂交亲本,配置复交组合。在繁殖的复交分离群体后代,通过在苗床喷洒0.2%草甘膦,去除不抗草甘膦棉苗;并在大田不防治棉铃虫的条件下,筛选抗虫棉株。而后在实验室利用特异引物对抗虫基因与抗草甘膦基因进行分子跟踪检测,将同时具有Bt基因与GR79+GAT基因的单株繁殖成株系,经大田筛选获得9个抗虫兼抗草甘膦的优良品系。然后对育成品系进行产量比较试验,结果显示,其中品系BG-6不但实现了抗虫与抗草甘膦基因的聚合,而且该品系的皮棉产量水平较高、纤维品质表现良好:纤维长度达30.9 cm、比强度30.1 cN tex^(-1)、马克隆值4.9。对产量性状与纤维品质性状相关分析显示,只有衣分与棉纤维整齐度呈极显著负相关(r=-0.838**),其他产量性状与纤维品质性状均不存在显著相关性。文章最后得出结论:在复合杂交组合的分离后代,通过在苗床喷洒草甘膦筛选抗性棉苗,再结合大田不治虫筛选抗虫单株;而后在室内对2种抗性基因进行PCR分子跟踪检测,再在大田对产量性状与品质性状进行系统选育,可实现抗虫与抗草甘膦基因以及高产与优质性状的多元聚合。

海陆杂交长绒棉棉铃、纤维品质性状及相关性分析

【目的】明确海陆杂交长绒棉的棉铃、纤维品质性状及相关性,为选育高产海陆杂交长绒棉提供参考依据。【方法】以自主选育的抗虫陆地棉种质系为母本、生产上推广应用的新疆长绒海岛棉品种为父本,配制海陆杂交棉新组合,分析23个海陆杂交棉组合F1代的棉铃、纤维品质性状以及相关性。【结果】23个海陆杂交棉组合F1代单铃重变幅为3.7~5.0 g,单铃重超过4.2 g的组合有12个,变异系数为9.0%;衣分变幅为20.1%~36.7%,衣分超过30.0%的组合有5个,变异系数为10.7%。不同组合F1代纤维长度变幅为34.5~38.5 mm,纤维长度在35.0 mm以上的组合有22个,变异系数为2.6%;纤维比强度变幅为34.8~41.8 cN/tex,纤维比强度超过39.0 cN/tex的组合有9个,变异系数为5.3%;马克隆值变幅为2.8~4.2,马克隆值A级的组合有10个,变异系数为11.8%。海陆杂交棉的单铃重与不孕籽率呈极显著负相关(r=-0.683**)、与每囊粒数呈极显著正相关(r=0.660**)、与每铃囊数呈显著正相关(r=0.495*);海陆杂交棉的纤维整齐度与纤维长度、纤维比强度呈极显著正相关(r=0.578**、r=0.639**),与伸长率呈显著正相关(r=0.506*);衣分与纤维长度呈显著负相关(r=-0.475*)。在23个海陆杂交棉组合中,W042×新海53号、W046×新海54号、W047×新海54号的棉铃性状与纤维品质性状已呈现同步改良。【结论】利用陆地棉与长绒海岛棉的杂交互补优势,可以实现长绒棉产量性状与纤维品质性状的同步改良。

Association analysis of fiber quality traits and exploration of elite alleles in Upland cotton cultivars/accessions(Gossypium hirsutum L.)

Exploring the elite al eles and germplasm acces-sions related to fiber quality traits wil accelerate the breeding of cotton for fiber quality improvement. In this study, 99 Gossypium hirsutum L. accessions with diverse origins were used to perform association analysis of fiber quality traits using 97 polymorphic microsatel ite marker primer pairs. A total of 107 significant marker-trait associations were detected for three fiber quality traits under three different environments, with 70 detected in two or three environments and 37 detected in only one environment. Among the 70 significant marker-trait associations, 52.86% were reported previously, implying that these are stable loci for target traits. Furthermore, we detected a large number of elite al eles associated simulta-neously with two or three traits. These elite al eles were mainly from accessions col ected in China, introduced to China from the United States, or rare al eles with a frequency of less than＆amp;nbsp;5%. No one cultivar contained more than half of the elite al eles, but 10 accessions were col ected from China and the two introduced from the United States did contain more than half of these al eles. Therefore, there is great potential for mining elite al eles from germplasm accessions for use in fiber quality improvement in modern cotton breeding.

Construction of a linkage map and QTL mapping for fiber quality traits in upland cotton (Gossypium hirsutum L.)

With the development in spinning technology, the improvement of cotton fiber quality is becoming more and more important. The main objective of this research was to construct a high-density genetic linkage map to facilitate marker assisted selection for fiber quality traits in upland cotton (Gossypium hirsutum L.). A genetic linkage map comprising 421 loci and covering 3814.3 cM, accounting for approximately 73.35% of the cotton genome, was constructed using an F2 population derived from cross GX1135 (P 1 )×GX100-2 (P 2 ). Forty-four of 49 linkage groups were assigned to the 26 chromosomes. Fiber quality traits were investigated in F2 population sampled from individuals, and in F2:3 , and F2:4 generations sampled by lines from two sites and one respectively, and each followed a randomized complete block design with two replications. Thirty-nine quantitative trait loci were detected for five fiber quality traits with data from single environments (separate analysis each): 12 for fiber length, five for fiber uniformity, nine for fiber strength, seven for fiber elongation, and six for fiber micronaire, whereas 15 QTLs were found in combined analysis (data from means of different environments in F2:3 generation). Among these QTLs, qFL-chr5-2 and qFL-chr14-2 for fiber length were detected simultaneously in three generations (four environments) and verified further by combined analysis, and these QTLs should be useful for marker assisted selection to improve fiber quality in upland cotton.

南疆陆地棉杂种F2的遗传分析及遗传主效聚类

采用加性-显性及其与环境互作的遗传模型对298个陆地棉品种(系)及其884个F_(2)组合在新疆南疆阿拉尔垦区4个产量性状和5个纤维品质性状2年的资料进行遗传分析,并对亲本的加性效应和显性效应进行了聚类,以明确各类品种(系)的育种利用价值。结果表明,在南疆陆地棉“矮(0.8~1.0 m)、密(225,000~300,000株hm^(-2))、早、膜”高密度种植模式下,298个亲本的加性效应被分为12类。第2类的23个品种(系)产量(除衣分外)和纤维品质性状的加性效应较高,可通过这类品种(系)间杂交较易获得产量性状和纤维品质性状兼优的后代。第8类品种(系)的纤维品质性状的加性效应较高,第4类品种(系)的产量性状加性效应较高,通过2类品种间杂交可以获得产量性状和纤维品质性状互补的后代。298个亲本的显性效应被分成了9类。第8类包括8个品种(系),其产量性状和纤维品质性状(除马克隆值外)的显性效应较高,可作为综合利用产量性状和纤维品质性状杂种优势兼优的一类亲本。产量性状的显性效应平均值较高的是第8类,第3类的纤维品质性状的显性效应较高。

西北内陆早熟陆地棉品种的综合评价及育种演化

【目的】综合评价近30年西北内陆棉区审定的早熟陆地棉品种,阐述该区域育成品种主要性状的育种演变规律,为西北内陆棉花新品种选育和主栽品种推荐提供参考依据。【方法】2020年和2021年分别在甘肃敦煌和新疆石河子对110个1988-2021年西北内陆棉区审定的早熟陆地棉品种与早熟、产量、纤维品质和株型相关的12个主要性状的表型进行鉴定;利用聚类分析、相关性分析和主成分分析等方法,对品种表型特征进行综合评分,筛选优良品种,并对其主要性状进行育种演化分析。【结果】110个早熟陆地棉参试品种的12个主要性状表型值分布范围较大,变异系数由大到小依次为:果枝长度>单株结铃数>吐絮率>单铃重>马克隆值>纤维强度>衣分>纤维长度>开花时间>果枝夹角>伸长率>整齐度。通过聚类分析将110个早熟陆地棉品种分为Ⅰ、Ⅱ、Ⅲ和Ⅳ4个类群,它们分别为优良纤维品质、早熟、松散株型和高产的品种类群。相关性分析表明,早熟性与产量和纤维品质相关性状均呈负相关,产量构成性状与纤维品质性状呈正相关,且多数性状之间达显著或极显著水平。利用主成分分析将12个主要性状简化为4个主成分,其累积贡献率达66.92%;并对110份早熟陆地棉品种进行综合评分,评分排名第一的品种为中棉113(0.67),该品种具有早熟、高产、纤维品质优良和株型相对松散等特征。进一步分析发现,甘肃审定品种的早熟性显著优于西北内陆和新疆审定品种,产量和纤维品质相关性状显著低于西北内陆和新疆审定品种。西北内陆早熟陆地棉品种在30多年的演化过程中,多数产量和纤维品质相关性状呈显著上升的变化趋势,株型向更为紧凑的趋势演变;早期育成品种的单株结铃数与单铃重、衣分、纤维长度和强度呈负相关,而近期育成品种单株结铃数与单铃重、衣分、纤维长度和强度呈正相关。【结论】西北内陆早熟陆地棉品种在育种改良过程中,与产量和纤维品质相关的主要性状指标分布广泛,逐年呈显著提升的演变趋势;近期育成品种已实现了单株结铃数与纤维长度和强度的协同提高。

陆地棉RIL群体产量与纤维品质性状QTL定位

棉花是世界首要的天然纤维作物,同时也是重要的蛋白和油料作物.该研究构建了一个包含184个单株的(渝棉1号×超早3号)重组近交系群体.利用SSR和SLAF-seq SNP分子标记共同构建高密度遗传图谱,结合多种环境鉴定产量和纤维品质性状表型,定位棉花产量和纤维品质性状的QTL.研究结果表明:①对8020个SSR与SNP标记进行遗传连锁分析,构建的遗传图谱共2945个位点(41 SSR和2904 SNP),遗传长度为4650.71 cM,覆盖陆地棉基因组总长的98.30%;②共定位到76个QTL,包括35个产量性状QTL,41个纤维品质性状QTL,LOD值分布在2.50~7.76之间,解释表型变异率为6.4%~23.4%;③10个QTL在两个及以上环境被检测到,为环境稳定QTL.

陆地棉棉籽主要品质性状与农艺性状的遗传变异分析

为通过农艺性状、纤维性状预测棉籽品质,以27份陆地棉为试验材料,对其10个农艺性状、3个种子品质性状和5个纤维品质性状连续2年进行鉴定,利用方差分析、相关性分析、主成分分析和聚类分析对农艺性状、纤维性状与种子品质性状间的关系进行解析。结果表明,油分含量与衣分呈极显著负相关,与果枝数呈极显著正相关;棉酚含量与叶面积呈显著负相关。主成分分析提取出6个主成分,累计贡献率为78.755%,其中第3主成分和第5主成分为棉籽副产品因子,贡献率为20.470%。综合分析得出果枝数、衣分和叶面积与棉籽副产品关系密切。以上结果为深入研究农艺性状与棉籽油分、蛋白质和棉酚的内在关系奠定了基础,为选育特种棉提供了理论参考。

乙烯利催熟对优质陆地棉纤维品质的影响

提高陆地棉纤维品质是棉花育种的目标之一,筛选性状优良、遗传稳定且对乙烯利不敏感的基因型材料,可为棉花育种提供方向,并可提高育种效率。本研究采用两因素随机区组设计,对242个纤维品质优异的陆地棉品系开展喷施乙烯利试验,获得所选陆地棉品系的5个纤维品质性状(纤维长度、整齐度、马克隆值、比强度、伸长率)试验数据,对这些性状进行方差分析,估算这些品系的基因型效应值,并对每个品系纤维品质性状乙烯利喷施与否的效应进行分析。结果表明,棉纤维的这5个品质性状都具有极显著的基因型效应,且在表型方差的占比中遗传方差的比例大于误差方差,表明这5个品质性状受遗传因素的作用较大;同时基因型与处理互作达到极显著水平,表明在乙烯利喷施与否的两个不同处理下,这些品系的5个纤维品质性状对乙烯利的敏感性不同。

Modified fiber qualities of the transgenic cotton expressing a silkworm fibroin gene

A silkworm gene for fibroin was introduced into the upland cotton WC line by Agrobacterium-mediated transformation. PCR detection for fibroin, nptII and gus genes, Kanamycin (Km)-resistance analysis and GUS-histochemical assay were conducted on 30 regenerated plants from 9 callus lines, and 17 positive plants were obtained by these 5 screening methods. By Km-resistance analysis and PCR for fibroin, 6 homozygous lines in T3 were obtained. Southern blot and Northern bolt demonstrated that the fibroin gene was inserted into the genome of these 6 lines, stably inherited and expressed. Compared to the control, the surface structure of mature fiber in the 6 lines was significantly distorted and an increased number of convolution was observed by scanning electron microscopy (SEM). Fiber quality traits analysis indicated that fiber elongation of the 6 homozygous lines was all increased and fiber strength of 3 lines was enhanced. These results indicated that fibroin expression influenced cotton fiber structure and quality, suggesting that fibroin has great potential for improving cotton fiber quality by genetic engineering.