棉花不同铃重类型种质主要纤维性状遗传及其变异

以中棉所48的母本S9708与不同铃重大小的父本杂交,配置6个F2群体,采用SAS 8.0软件对各组合亲本、F1和F2的铃重和衣分及纤维品质等数量性状进行统计分析。结果表明:在所有F2群体中纤维性状都有极显著差异。铃重和麦克隆值的变异系数较大,其次是衣分和纤维强度,而纤维长度、伸长率和整齐度变异系数较小。在杂交早代群体中,仍然表现亲本的铃大、衣分高、纤维长、强度高、整齐度好等优良特性。这表明,在杂种优势利用选择亲本时,选择大铃、高衣分、优质纤维材料仍较为重要。     

Performance and combining ability in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) populations with diverse parents

Improving fiber quality properties of cotton is important for increasing the efficiency of manufacturing textiles, including enhancing yarn quality and spinning performance. This study was conducted to determine if we could identify valuable cotton cultivars to use as parents in breeding programs with the goal of improving fiber properties. Seven parents were combined in a diallel design and selfed to obtain 21 F₂ populations. Positive general and specific combining ability effects were observed for all traits. General combining ability tended to be larger than specific combining ability, indicating these traits are controlled primarily by additive genetic effects. Correlations among traits were generally positive except for lint yield correlations with fiber strength and length. For improving the fiber quality measures of strength and length, line 7235 shows excellent general combining ability effects. SG125 would provide elite germplasm to increase agronomic measures of lint yield and lint percent. The MD51 genotype has the highest potential among the genotypes tested here to provide germplasm combining both improved yield and fiber strength. These parents, or their selected progeny, should be useful in a breeding program to generate variability from which selection can be used to identify lines with improved fiber and/or agronomic properties.     

Evaluation of genetic variances, heritabilities, and correlations for yield and fiber traits among cotton F2 hybrid populations

Summary F₂ hybrid cultivars continue to occupy a small portion of the cotton (Gossypium hirsutum L.) production are in the United States, but occupy a larger proportion of the production area in some other countries. Sixty-four F₂ hybrids resulting from crosses of four commercial cultivars and 16 pest-resistant germplasm lines were evaluated for five fiber and four yield traits in four environments at Mississippi State, MS. An additive-dominance genetic model was employed for these traits. The minimum norm quadratic unbiased estimation (MINQUE) method was used with a mixed model approach for estimating genetic variance and covariance components and for predicting genetic correlations. This study investigated genetic variances, heritabilities, and genetic and phenotypic correlations between agronomic and fiber traits among these 64 F₂ hybrid populations and discussed the usefulness of these populations for use as hybrids or for selections for pure lines.Dominance variance accounted for the major proportion of the phenotypic variances for lint yield, lint percentage, and boll size indicating that hybrids should have an advantage for these traits compared to pure lines. A low proportion of additive variance for fiber traits and the significant additive x environment variance components indicated a lack of substantial useful additive genetic variability for fiber traits. This suggests that selections for pure lines within these F₂ populations would have limited success in improving fiber traits. Genetic and phenotypic correlation coefficients were of comparable magnitude for most pairs of characters. Fiber strength showed a positive additive genetic correlation with boll weight. Dominance genetic correlations of fiber strength with elongation and 2.5% span length were also significant and positive; however, the additive genetic correlation of length and strength was zero.Contribution of the USDA-ARS in cooperation with the Mississippi Agric. and Forestry Exp. Stn.     

Heterosis,combining ability and genetic effect,and relationship with genetic distance based on a diallel of hybrids from five diverse <Emphasis Type="Italic">Gossypium barbadense</Emphasis> cotton genotypes

The cultivated tetraploid Gossypium barbadense L. cotton produces superior natural fibers for the textile industry in the world. However, the possibility in utilization of heterosis to further increase its lint yield has not been extensively explored. In this study, two commercial US Pima cotton cultivars and three exotic G. barbadense lines, together with all of their possible hybrids in F₁ and F₂ progeny without reciprocals, were tested for lint yield, yield components, and fiber quality traits in four environments in 2005–2007. With a few exceptions, genotype (G), environment (E), and G × E were all significant or highly significant for all the traits studied. General combining ability (GCA) variances for all the traits in both F₁ and F₂ were also significant, while specific combining ability (SCA) variances were detected only for lint yield, fiber length, and micronaire in both generations and boll weight in F₁. GCA × E was also detected for lint percent, seed index, and fiber length in both F₁ and F₂, and boll weight in F₁, but none of the traits had significant SCA × E. As a group, F₁ and F₂ out-yielded the parent group by 20–40% and 6–10%, respectively. Mid-parent heterosis (MPH) for lint yield in F₁ was generally positive, ranging from ?4.7 to 116.4% with an average of 21.2–48.7%, while lint yield MPH in F₂ ranged from ?23.3 to 69.4% with an average of 6.4–12.4%. However, useful heterosis in lint yield was only detected in the hybrid between the two US commercial cultivars Pima S-7 and DP 340. MPH for other traits was low or not detected. MPH in F₂ was lower than that in F₁ but they were generally positively correlated. The genetic distances (GD) of the parents (based on 467 polymorphic RAPD and AFLP markers) between the five parents was not consistently correlated with MPH and SCA of their hybrids and dominant effects for lint yield and other traits. However, significant and positive correlations between GD of parents and the performance of their hybrids were detected for lint yield, lint percentage, and lint index in both F₁ and F₂ in most of the tests. GD of parents was also correlated with their GCA and additive effects in lint yield, lint percent, lint index, micronaire, plant height, and elongation. The results suggest that the close correlation between GD and hybrid performance per se was mainly due to the existence of GCA and additive effects from parents.     

陆地棉不同群体主要性状的遗传力及杂种优势分析

以1个高强纤维品系为父本,6个常规棉品系、5个转Bt基因抗虫棉品系和5个彩色棉品系为母本配制杂交组合,利用AD模型,分析了3个群体杂交组合主要性状的遗传力和杂种优势表现。结果表明,常规棉群体和抗虫棉群体的衣分、籽棉产量等性状基因显性效应对杂种一代性状形成起主导作用,彩色棉群体的籽棉产量受加性和非加性效应共同控制,而衣分的遗传变异主要来自基因的加性效应。常规棉群体的比强度以显性效应为主,抗虫棉和彩色棉群体的比强度以加性效应为主。3类群体中2．5％跨长和马克隆值的遗传效应均以加性效应为主,同时受非加性效应的影响也较大。常规棉群体和抗虫棉群体的产量性状有一定的杂种优势,纤维长度和细度基本上没有优势,纤维强度有显著的负优势,但彩色棉群体的纤维长度和强度有一定的正向优势。因而,在品种改良上,可以利用常规棉和转基因抗虫棉的杂种优势大幅度提高产量,利用彩色棉的杂种优势来提高纤维品质。     

Germplasm for genetic improvement of lint yield in Upland cotton: genetic analysis of lint yield with yield components

Determination of genetic effects for lint yield and yield components in cotton (Gossypium hirsutum L.) germplasm is critical for its utilization in breeding programs. This study was designed to apply the conditional approach and an additive and dominant model to analyze genetic effects for lint yield and yield components. Forty-eight F₂ populations derived from crosses between four existent Upland cotton cultivars as female parents and 12 germplasm lines as male parents were evaluated at two locations in 2008 and 2009. Conditional and unconditional variance components were estimated by the mixed linear model based conditional approach. Lint yield and yield components were mainly controlled by genotypic effects, i.e., additive variance and dominance variance (≥66 % of total phenotypic variation). Lint percentage and lint index had the highest proportions of additive variance component to the total phenotypic variances. SP156 and SP205 had positive additive effects for lint yield and yield components, and were also parents of the most hybrids with positive predicted dominant effects. Therefore, these two lines are good combiners for development of both pure lines and hybrids. Positive additive contribution effects to lint yield from lint percentage, boll number, boll weight, and seed index were detected in different parents. Adding seed index to boll number and lint percentage increased additive contribution effects to lint yield from these two components relative to the contribution effects from either boll number or lint percentage alone. Results in this study suggest that boll number, lint percentage, and seed index should be balanced in pure line development.     

Construction of a genetic linkage map and QTL analysis of fiber-related traits in upland cotton (Gossypium hirsutum L.)

A genetic linkage map with 70 loci (55 SSR, 12 AFLP and 3 morphological loci) was constructed using 117 F₂ plants obtained from a cross between two upland cotton cultivars Yumian 1 and T586, which have relatively high levels of DNA marker polymorphism and differ remarkably in fiber-related traits. The linkage map comprised of 20 linkage groups, covering 525 cM with an average distance of 7.5 cM between two markers, or approximately 11.8% of the recombination length of the cotton genome. The present genetic linkage map was used to identify and map the quantitative trait loci (QTLs) affecting lint percentage and fiber quality traits in 117 F_2:3 family lines. Sixteen QTLs for lint percentage and fiber quality traits were identified in six linkage groups by multiple interval mapping: four QTLs for lint percentage, two QTLs for fiber 2.5% span length, three QTLs for fiber length uniformity, three QTLs for fiber strength, two QTLs for fiber elongation and two QTLs for micronaire reading. The QTL controlling fiber-related traits were mainly additive, and meanwhile including dominant and overdominant. Several QTLs affecting different fiber-related traits were detected within the same chromosome region, suggesting that genes controlling fiber traits may be linked or the result of pleiotropy.     

Genetic impacts of fiber sugar content on fiber characters in Sea Island cotton, Gossypium barbadense L.

A genetic model with additive effect, dominant effect, additive × additive effect, and their interaction with environment effect (GE) was employed to analyze the 2-year data of F₁ and F₂ hybrids from 5 × 4 diallel cross, whose parents were Sea Island cotton with different fruit branch types. Unconditional and conditional genetic variances were analyzed to demonstrate genetic impacts of fiber sugar content on fiber characters. Results of unconditional genetic variances showed that dominance × environment interaction effect and additive × additive epistatic effects mainly controlled the genetic variation of fiber sugar content, and environment influenced the inheritance of fiber sugar content. Fiber uniformity, fiber elongation, and fiber micronaire were mainly controlled by dominance × environment effects. Fiber strength was mainly controlled by the interaction of additive × additive epistatic effects and the environment. Analysis of correlation coefficients indicated that the varieties or hybrids with high-fiber sugar content had short fiber, low-fiber uniformity, strength, and fineness, which indicated the close co-variation between fiber quality traits and fiber sugar content. Relatively better fiber quality traits could be obtained effectively through selecting parents with low-fiber sugar. Fiber sugar content of different parents had different genetic effect on fiber quality traits.     

高品质陆地棉与不同类型品种杂种的遗传及优势分析

 比较分析了高品质棉与高品质棉、常规品质转Bt基因抗虫棉杂交组合主要性状的遗传效应和杂种优势。结果表明,两类杂种的子棉产量存在极显著的加性和显性效应;高×高杂种的株铃数和铃重具有极显著的显性效应,高×常抗杂种受加性和显性效应共同控制;两类杂种的纤维品质性状以加性效应为主,但显性效应对纤维长度也起较大作用。高×高杂种的F₁子棉产量和株铃数具有正向超亲优势,高×常抗杂种表现为负向超亲优势;两类杂种的纤维长度和麦克隆值具有较小的正向平均优势,比强度具有负优势。高×高杂种可以在保持亲本良好品质的基础上,利用产量和产量性状的正向超亲优势来提高产量。     

Analysis of decision-making coefficients of three main fiber quality traits for upland cotton (Gossypium hirsutum L.)

The analysis of genetic correlations between fiber length (Len), strength (Str), micronaire, and 12 other traits was conducted using the additive (A)-dominance (D) genetic model, which considers genotype × environment interaction effects, in intraspecific upland cotton (Gossypium hirsutum L.) hybrids to effectively improve the quality of cotton cultivars in high planting density cases. Decision-making coefficients were computed based on the genetic correlation and path analysis of three fiber quality traits. The decision-making coefficient analysis of three fiber traits in cross breeding was beneficial for the improvement of Len by increasing the additive effects of Str and length of boll (LB) and decreasing lint percentage (LP), boll number of the top three fruit-bearing branches. The analysis was also beneficial for the improvement of Str and fiber fineness by increasing or decreasing the additive effects of other traits. Utilizing heterosis in hybrids was beneficial to the heterosis of Len by selecting the high dominance effects of number of nodes of the 1st fruit-bearing branch and LB and decreasing the dominance effects of diameter of boll (DB) and LP and for improving Str by increasing the dominance effects of DB and decreasing the dominance effects of number of fruit-bearing branches and number of nodes of the main stem (NNMS). Utilizing heterosis was also beneficial for improving fineness by increasing the dominance effects of LB, Str, and lint yield and decreasing the dominance effects of NNMS and Len.     

转基因抗虫棉纤维品质性状的遗传分析

 根据ADAA遗传模型分析了7个转基因抗虫棉亲本、两个非转基因抗虫亲本和36个半双列杂交F1的纤维品质性状的两年资料,估算各项遗传方差和成对性状间的遗传相关性。结果表明,转基因抗虫棉纤维品质的5个性状受加性、显性和上位性的共同控制,其中麦克隆值、2.5%纤维长度和纤维比强度以基因显性效应为主,麦克隆值和纤维整齐度以上位性效应为主。除纤维比强度外,其余4个纤维品质性状都受到环境互作效应的影响,且影响较大。遗传相关分析表明,纤维比强度与2.5%纤维长度的基因型相关和表型值相关达极显著水平,其中加性相关未达显著水平,显性相关达极显著水平。比强度与麦克隆值的基因加性相关也达极显著水平,但表型相关未达显著水平。利用亲本和F₁的资料预测了F₂的基因型值和杂种优势。结果表明,F₂代的麦克隆值、伸长率、2.5%纤维长度、整齐度、纤维比强度的中亲优势分别为1.0%, 8.5%, 0.8%, 0和2.9%, 无超亲优势。     

转基因抗虫杂交棉杂种后代及其亲本纤维品质比较研究

2000-2004年,以转基因抗虫棉农杂62、H16、H64的F1、F2、F3及其亲本为材料,检测了主要纤维品质指标.结果表明,杂种后代的纤维长度、整齐度和亲本之间无显著差异,杂种后代纤维平均伸长率与高值亲本差异显著.但在比强度和麦克隆值方面,表现出显著的杂种优势,F1杂种优势显著地高于亲本及F2和F3.纤维比强度的中亲优势农杂62 F1平均为11.84%;农杂62F1和H16F1的高亲优势分别为9.46%、14.34%.F1、F2、F3纤维长度、整齐度、麦克隆值、伸长率等品质指标群体平均数之间虽然差异很小,但F1、F2、F3群体纤维品质性状均有相似的变异个体分布.F1群体纤维品质优于F2、F3,F2群体纤维品质略优于F3.     

显性无腺体与隐性无腺体陆地棉品种间杂种二代利用研究

利用４个隐性低酚棉品系为母本，５个显性无腺体品系为父本，按不完全双列杂交（ＮＣⅡ）设计配制２０个组合，利用亲本、Ｆ１和Ｆ２材料采用ＡＤＡＡ模型研究表明，衣分以加性效应为主，其余产量及产量构成因素以显性遗传效应为主。子棉产量和铃重有较低的上位遗传效应。纤维品质性状中，绒长与整齐度以显性遗传效应为主，绒长还存在少量上位效应；比强度与伸长率仅存在显著的加性遗传效应，麦克隆值以加性遗传效应为主。Ｆ１皮棉产量、第一次收花率、单株铃数、铃重和衣分的群体超亲优势平均值分别为：２７．９％、１８．７％、１６．２％、９．７％和１％，Ｆ２分别为：１０．８％、５．１％、４．５％、４．６％和－１．２％。Ｆ１绒长的群体平均优势为２．５％，比强度和伸长率为－１．８和０．８％，麦克隆值和整齐度分别为－０．２％和－２．７％。Ｆ２绒长略呈下降趋势，比强度、伸长率和麦克隆值Ｆ２与Ｆ１相近，整齐度Ｆ２略优于Ｆ１。表明了显性无腺体基因的杂种优势利用前景广阔。     

Commonality analysis and selection of parents for within-boll yield components in upland cotton

Relationships between lint yield and within-boll yield components are important for genetic improvement of lint yield in cotton (Gossypium hirsutum L.) cultivars. F₂ plants derived from crosses between germplasm lines and high yielding cultivars were analyzed to determine the contributions of within-boll yield components to lint yield and to select parents with desirable combining ability for multiple within-boll yield components. Forty-five F₂ hybrids were planted at two field sites in 2010 and 2011 with 4 and 3 replicates, respectively. There were a total of six yield components analyzed including lint percentage (LP), seed number per boll, lint weight per seed (LW_S), seed surface area per seed, lint weight per unit seed surface area (LW_SA), and lint number per unit seed surface area (LN_SA). The contributions of these yield components to lint yield were analyzed by commonality analysis that separated the contributions to lint yield into the unique contributions of single yield components and the common contributions of the single yield components with one or more other yield components. The unique contributions of the six yield components to lint yield ranged from 1.6 to 21 % of total variation for lint yield in the 2-year experiments. The greatest common contributions to lint yield among all combinations of the six yield components were identified for a combination of four components, LP, LW_S, LW_SA, and LN_SA with 67 and 44 % of the total variation of lint yield in 2010 and 2011, respectively. Results suggest that all four of these yield components should be considered simultaneously in breeding for genetic improvement of lint yield. The germplasm line SP225 was detected as a good combiner with positive general combining ability (GCA) for LP (1.4 %), LW_SA (0.03 mg mm^?2), and LN_SA (14.3 no mm^?2), and favorable GCA for fineness (?3.1 mg km^?1).     

Genetic association of within‐boll yield components and boll morphological traits with fibre properties in upland cotton (Gossypium hirsutum L.)

Knowledge of genetic relationships between within‐boll yield components and fibre quality is essential for simultaneous improvement of lint yield and fibre quality in upland cotton (Gossypium hirsutum L.). Nine parents and their F₁ progeny with reciprocals from a 3 × 6 factorial mating design were grown in 2008 and 2009. Seven within‐boll yield components and two boll morphological traits and the three fibre quality parameters were analysed based on a conditional additive/dominance (AD) genetic model. Results showed that boll length contributed to the largest proportion of phenotypic, additive and dominance variances for UHM length; seed index contributed to the largest proportion of phenotypic and additive variances for fibre strength; boll width made the largest contribution to phenotypic and additive variances and the second largest contribution to dominance‐by‐environment interaction variance for micronaire, indicating that they played an important role than the other traits for fibre length, strength and fineness/maturity, respectively. It is worthy of note that those correlations between boll shape and fibre quality apply only to the nine parents and the resultant hybrids in this study and do not imply a cause and effect relationship.     

棉花三系杂交种不同生态区遗传效应及优势表 现简

 选用3个核背景不同的恢复系材料和7个不同的哈克尼西棉胞质不育材料作为亲本,根据NCⅡ遗传交配设计,配置了21个杂交组合,分别在黄河流域棉区河南安阳、黄淮流域棉区河南西华和长江流域棉区安徽无为3个生态区试点种植,通过性状调查与室内考种,采用朱军的ADE模型,进行数据分析。结果表明,子棉和皮棉产量主要受到加性、显性、加性与环境互作效应的影响,衣分和铃数主要受加性、加性与环境互作效应的影响,而铃重则只受加性与环境互作效应的影响;对于纤维品质性状,纤维长度、马克隆值、比强度和整齐度受到加性效应的影响,同时,纤维长度和马克隆值还与加性与环境互作效应相关;遗传率分析与遗传方差分量分析表现一致;产量及产量性状之间有一定的遗传相关,而纤维品质性状之间的遗传相关则较小,产量和纤维品质性状之间也存在着较少的遗传相关;杂交组合的产量竞争优势表现为安阳试点>西华试点>无为试点,说明与生态环境有关。在3个不同的生态区,研究了21个杂交组合的遗传效应及优势表现,研究结果对三系杂交组合选配有一定的指导意义。     

Lint development and properties of fifteen fuzzless seed lines of Upland cotton (Gossypium hirsutum L.)

Fifteen fuzzless seed lines in “obsolete” backgrounds of Upland cotton (Gossypium hirsutum L.) were obtained from the National Cotton Germplasm Collection and evaluated for fuzzless seed genotype, lint percent, and lint quality. Fourteen of these fifteen lines were found to be homozygous for the dominant fuzzless seed allele N ₁. Only one line was homozygous for the recessive fuzzless seed allele n ₂. The measured lint percent of each line was very stable through time, however, large variability existed between many of the N ₁ lines ranging from 0.7 to 23.6% lint. The lint percent for the n ₂ line was 24.4%. Scanning electron microscopy was used to differentiate patterns of lint initiation on 1 day post anthesis ovules. General patterns included: first, lint initiation restricted to the chalazal end of the seed crest; second, lint initiation along the seed crest and laterally around the chalazal end of the ovule; and third, lint initiation covered all but the micropylar end of the ovule. Lint quality was evaluated for each line using the Advanced Fiber Information System (AFIS) which included measurements of length, maturity, and fineness. The means of each measurement varied among the fuzzless seed lines with significant differences between fiber length, short fiber content, immature fiber content, fineness, and maturity ratio. No correlation was found between lint percent and any of the lint quality measurements. These lines will provide a valuable resource for the study of fiber initiation and lint quality.     

Heritability and predicted selection response of yield components and fibre properties in an inter-specific derived RIL population of cotton

Exploiting genetic variation through inter-specific breeding has improved cotton yield, fibre properties and adaptability. The objectives of this study were to examine heritability and predicted selection response of yield components and fibre properties in a recombinant inbred line (RIL) population from an inter-specific cross between Gossypium hirsutum (Gh) variety Guazuncho 2, and G. barbadense (Gb) line VH8-4602. A population of 93 and 82 RILs was tested in two seasons, with two parents and local controls, Sicot 75 (Gh) and Sipima 280 (Gb) in field experiments. Seed cotton samples hand harvested before and after defoliation were used to measure lint percent, boll weight, 100 seed weight and the lint to measure fibre length, uniformity, short fibre index (SFI), elongation, strength, micronaire, maturity ratio (MR), percent of maturity (PM) and fineness. There was large phenotypic variation for individual traits and transgressive segregation occurred in lint percent, lint weight/seed, fibre no./seed, uniformity, SFI, elongation, MR and PM. Narrow sense heritabilities were moderate for yield components (34.3–41.2%) and for key fibre properties, length, strength, micronaire and fineness (38.3–42.1%), which led to a predicted selection response of 6.7–24.0% for yield components and 3.9–10.9% for key fibre properties under a selection intensity of 10%. Favourable associations were found between key fibre properties, but an adverse association between lint percent and each of these fibre properties. Only five RILs were identified with desirable combinations. The results demonstrated the value of exploiting inter-specific variation to develop cotton germplasm and how breeding strategies can be improved.     

棉花杂交种F1、F2纤维品质性状比较研究

2001-2003年,通过田间试验、定位取样、分株收花、分别检测了杂交棉农杂62F1、F2的主要纤维品质指标。结果分析表明,F1、F2的纤维品质性状均为分离世代,F1、F2纤维长度、比强度、整齐度、麦克隆值、伸长率等品质指标群体平均数趋于一致,群体内个体纤维指标变异均呈正态分布,但峰值和偏斜度差异明显,F1群体中品质较优的个体显著多于F2。F2纤维的整体品质比F1差。     

光子陆地棉种质资源主要性状的遗传评价

以102份光子陆地棉材料为母本,分别与遗传标准系TM-1杂交,获得102个F₁群体。采用随机区组设计,设置3个重复,对光子陆地棉材料主要性状进行遗传评价。结果表明,调查的11个性状表型差异均较大,材料间产量性状(株高、果枝数、铃数、铃重、衣分和子指)差异大于纤维品质性状(纤维长度、纤维强度、马克隆值、整齐度和伸长率),特别是衣分、铃数等性状差异更明显; 除果枝数、马克隆值、伸长率以外,光子亲本群体其他性状的平均值都小于F₁群体。而亲本群体所有性状的变异系数均大于F₁,不同光子材料的杂种优势有很大差别,中亲优势和超亲优势也有很大的差别,有些种质某些性状的中亲、超亲优势为负值,其后代性状表现劣势; 纤维品质性状的中亲、超亲优势与毛子程度均呈负相关,而产量性状的中亲、超亲优势与毛子程度均呈正相关,说明可利用光子材料杂种优势改良纤维品质,而其后代产量性状的杂种优势利用受到限制; SSR分子标记遗传相似系数与各个性状的中亲、超亲优势的相关都不显著,说明在光子材料的育种中,杂种优势是不能通过亲本之间的遗传背景相似程度来预测的。