Response to selective pressure in early generation progenies of upland cotton (Gossypium hirsutum L.)

Summary Combining high fiber strength with high yield in upland cotton (Gossipium hirsutum L.) was been difficult. The cross combination, 69–120 × 6M-10, was chosen for this study because of the divergence of parents for fiber strength, seeds per boll and crop maturity. Forty F₂ plants were selected in 1974 solely on the basis of visual yield and 20 plants were randomly chosen to serve as a bulk check. The F₃ progenies, the bulk check, the parents and a commercial check were tested in 1975. From these results, five groups were established, consisting of four (10%) progenies each to represent high seed/boll, low seeds/boll, high fiber strength, low fiber strength and high yield in the 1976 test of F₄ progenies. This experiment was conducted to (a) compare the contributions of yield components to lint yield among groups of early generation progenies (F₃ and F₄) and (b) determine the phenotypic correlations between yield and quality attributes. The yield components, bolls/m², seeds/boll, fibers/seed, mean fiber length and micronaire, were included as well as fiber strength.No significant lint yield differences were found among the five groups. Progenies within groups did, however, differ in lint yield. The low and high seeds boll groups gave similar yield and fiber quality results. The low and high fiber strength groups gave similar yield but longer fiber was obtained with the high strength group.Stepwise regression analyses estimates show that the number of bolls produced per unit area, although the major contributor to lint yield for all groups, contributed only 66.9% of the total variation in the progeny group selected for high yield, with fibers/seed, mean fiber length, micronaire and seeds/boll accounting for 13.2%, 8.1%, 6.0%, and 5.8%, respectively. Correlations between the various yield components and fiber strength were low and mainly insignificant, indicating that minor alterations might be made in later generations without serious consequences.Potential gains from second-stage selective pressure upon yield-per-boll components following initial selection for lint yield are discussed.     

不同温度下外施6-BA和ABA对棉花(Gossypium hirsutum L.)产量和纤维品质的影响

以棉纤维比强度高的科棉1号、比强度中等的美棉33B 2个品种为材料,于2006-2007年在江苏南京设置大田分期播种试验,使棉铃发育处于不同温度条件,于棉株7～9果枝第1、2果节棉铃开花时喷施6-苄基腺嘌呤(6BA)和脱落酸(ABA),研究不同的铃期日均最低气温条件下6-BA和ABA对棉花产量和纤维品质的影响。结果表明:由晚播造成的低温降低了棉花产量及纤维品质。外施6-BA、ABA对棉株中部果枝铃铃重和纤维品质影响最大。正常播期下,外施6-BA可增加中部果枝棉铃铃重,外施ABA降低铃重,但二者对其纤维品质影响较小;迟播时,外施6-BA可提高中部果枝棉铃铃重,ABA处理的作用则相反,二者均可提高纤维长度和比强度、优化麦克隆值。不同的温度条件下,外施6-BA均提高了单株铃数、单株平均铃重和皮棉产量,外施ABA则降低了棉花单株铃数和产量。外施6-BA和ABA对高强纤维品种产量和纤维品质的影响较中强纤维品种更为明显。低温下,在棉铃发育初期喷施6-BA对改善棉纤维品质的效果最好。     

Association analysis of yield and fibre quality characters in interspecific population of cotton (Gossypium spp.)

Seed cotton yield and fibre quality are controlled by polygenes and highly influenced by the environment. Hence, selection merely based on yield is not effective. In order to enhance the yield potential of the cotton varieties, an understanding of the relationship among different characters is of more importance. Knowledge on the direct contribution of different characters to yield would be highly important for formulating a selection programme. Correlation and path coefficient analysis were carried out using 62 progenies of an interspecific backcross population (Gossypium hirsutum L. var. KC 3 x Gossypium barbadense L. var. Suvin) x KC 3. Genotypic correlation studies revealed that number of bolls per plant, boll weight, number of sympodia per plant, number of seeds per boll, seed index, lint index, days to first flowering, and plant height have a significant positive association with seed cotton yield per plant. Path coefficient analysis showed that number of bolls per plant contributed maximum direct effect to seed cotton yield per plant followed by boll weight and lint index. The highest positive indirect effect on seed cotton yield per plant was also observed through number of bolls per plant. This indicated that seed cotton yield per plant was highly influenced by number of bolls per plant directly and indirectly. Thus, a greater emphasis should be given to number of bolls per plant, boll weight, and lint index for increasing seed cotton yield per plant.     

Identification of QTLs for salt tolerance at germination and seedling stage of Sorghum bicolor L. Moench

Upland cotton (Gossypium hirsutum L.) hybrids display commercially useful levels of heterosis for lint yield. Cotton lint yield is primarily a multiplicative product of boll number and lint per boll, both of which can be further dissected into sub-components. Relationships among the yield components are complex where they further interact with the environment. To identify different yield components of hybrid cotton lint yield and their relationship with environment, three cotton varieties, DP51, STV474 and LA887 and, their respective hybrids were evaluated for lint yield components across five environments. Heterosis was observed for lint yield as well as yield components. The relationship between heterosis and mean environmental yield was negative for two hybrid combinations, whereas one hybrid showed increased heterosis from low to high yielding environments. Boll number was the major yield component contributing to lint yield. However, yield components contributing to the change in heterosis from low to high yielding environments were different for the three hybrids. The change in lint yield heterosis across environments was correlated with lint per boll and lint per seed for DP51 × STV474 and LA887 × DP51. Whereas, bolls number and boll retention were the main yield components contributing to higher lint yield heterosis of STV474 × LA887 in low yielding environments. Results also reveal effects of parental entries on lint yield as well as relationship of heterosis and environment.     

留营养枝棉花群体干物质积累分配规律研究

研究结果表明,留营养枝对棉花叶和生殖器官的干物质积累分配无显著影响,但影响主茎的生长,使主茎干物质积累量减少;早打主茎顶心促进营养枝的生长,群体总干物质积累量增加。从产量构成因素分析,留营养枝棉花主茎果枝结铃数量减少,平均单铃重略有降低,但由于叶枝结铃可以弥补主茎结铃损失,群体总结铃数加有增加,皮棉产量与对照无显著差异;留营养枝早打主茎顶心,营养枝结铃数量增加,单铃重降低,但衣分提高,对群体铃数及皮棉产量无显著影响。     

建国以来我国长江流域棉区棉花品种的遗传改良Ⅰ.产量及产量组分性状的改良

本文是我国长江流域棉区棉花品种遗传改良研究的系列报道之一, 目的在于探讨建国以来我国长江棉区棉花品种在产量和产量组分性状(株铃数、铃重和衣分)上遗传改良的成效. 对不同历史时期11个代表性品种两年7点的试验资料和30多年区域试验历史资料的研究表明, 建国以来, 我国长江棉区棉花品种的产量性状改良成效显著, 品种的产     

The relative contributions of yield components to lint yield of upland cotton,Gossypium hirsutum L.

Summary Stepwise regression analyses provided an estimate of the net effect of yield components on lint yield of Upland cotton. Data from strain tests in the Pee Dee, South Carolina, cotton breeding program for crop years 1968 and 1969 were used in these analyses. Lint yield/m² was the dependent variable. Independent variables were: bolls/m², lint/seed, and seeds/boll.Correlation analyses indicated the relationships among yield components. Partial correlation coefficients were utilized to show the order of variable addition in the regression equations. We found that bolls/m² assumes the major role in determining yield. The lint/seed component assmes the secondary role in the development of lint yield. Seeds/boll made a relatively larger total contribution only after lint/seed had made its contribution.These data indicate that selection pressure should be placed on prolificacy (bolls/m²) and seeds/boll, concommitantly with selection to maintain or increase lint/seed. Although the lint/seed component makes a relatively smaller total contribution to lint yield, it is necessary to maintain or increase this component to secure the increased contributions of seeds/boll.Cooperative investigations of the Plant Science Research Division, Agricultural Research Service, US Department of Agriculture and the Tennessee and South Carolina Agricultural Experiment Stations. South Carolina Technical Contribution No 954.     

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).     

不同抗虫棉基因型的生长发育和产量表现

以33B为对照,选择山东育成的5个常规、2个杂交Bt抗虫棉品种连续进行了4年的比较观察。结果表明,供试Bt常规抗虫棉大致可分为早发和晚发两种类型,前者除具有33B结铃性强、抗早衰等优点外,单株总生物产量、铃重和衣分也有所提高,4年平均皮棉产量比对照33B提高5%～6%,但仍具有前期生长慢、生育期偏长的特点;后者前期生育快,早熟性好,铃重和衣分显著提高,4年平均皮棉比对照33B增产5%～7%,但结铃数下降,易早衰。两个Bt杂交抗虫棉品种较好地协调了产量构成三因素之间的关系,4年平均皮棉产量比对照33B增产18%～19%。     

转基因抗虫棉产量性状的遗传效应及其杂种优势分析

采用加性-显性与环境互作的遗传模型,分析了9个亲本和36个F1的皮棉产量、单株铃数、铃重和衣分的两年资料,估算了转基因抗虫棉各项遗传方差和成对性状间各项遗传效应的相关性.结果表明,转基因抗虫棉的产量性状受加性和显性效应共同控制,皮棉产量、铃重和衣分都以基因的显性效应为主,而单株铃数是以加性效应为主,单株铃数和衣分还具有基因与环境互作效应.遗传相关分析表明,转基因抗虫棉的皮棉产量与单株铃数的基因型和表现型相关系数都比较大而且比较接近;皮棉产量与单株铃数、铃重和衣分的加性相关系数都达到极显著水平,而且皮棉产量与单株铃数、衣分的数值比较大.利用亲本和F1的资料预测了F2基因型值和杂种优势,结果表明,转基因抗虫棉F2的皮棉产量、单株铃数、铃重和衣分的群体平均优势分别为4.0%、5.1%、-1.3%和3.2%,群体超亲优势分别为-7.3%、-6.0%、-4.2%和-0.5%.     

棉花苗期耐低钾能力筛选指标研究及其与产量、品质的关系

以长江流域下游棉区的12个棉花主栽品种为研究材料,在人工气候室水培和田间种植条件下进行棉花苗期耐低钾能力筛选指标研究。结果表明,低钾会放大棉花苗期关于钾素吸收利用和光合碳同化等生理特性上的品种间差异幅度。土壤严重缺钾时会显著降低棉花铃数、铃重及衣分,其中铃数响应土壤缺钾最为敏感,而在铃重组成中纤维质量对土壤缺钾的响应幅度大于棉子质量。通过对比基于棉花苗期不同生理指标和最终产量与品质指标的筛选结果,发现综合考虑棉花苗期叶片SuSy活性、SPAD值和单株叶片生物量3项指标的低钾胁迫系数对棉花最终产量与品质的耐低钾能力具有较好的预测效果。通过试验筛选出低钾敏感型棉花品种泗杂3号和耐低钾型棉花品种泗棉3号,二者可作为进一步研究低钾环境下棉花产量、品质形成机理的理想试验材料。     

短季棉霜前皮棉产量及其相关性状的关联度分析

对短季棉霜前皮棉产量及其相关性状的关联度分析,可知霜前花率和衣分对霜前皮棉产量的影响较大,单株铃数和单株果枝数次之,铃重、果枝始生节位、株高、子指和生育期等对霜前皮棉产量的影响较小.选育过程中要分清主次,抓主要性状的改良,改进霜前花率和衣分并与其它性状相协调,提高霜前皮棉产量.     

陆海BC4F3和BC4F4代主要农艺性状的相关和通径分析

为了更有效地对棉花农艺性状进行选择,缩短选择育种的年限,通过采用相关、偏相关、通径以及回归分析的方法,研究了陆海高代回交自交后代BC4F3和BC4F4群体的6个农艺性状间的关系。结果表明：铃重、衣分、铃数、果枝数、株高与单株皮棉产量呈极显著正相关,其中铃数是决定单株皮棉产量最主要的因素,在BC4F3和BC4F4代对单株皮棉产量的直接通径系数分别为0.6650、0.6689,其次是铃重和衣分,两者的贡献大小相当;果枝数和株高可以通过铃数对单株皮棉产量起较大的正向促进作用;最优回归方程显示,铃重、衣分、铃数和株高对单株皮棉产量有显著的正向影响。本研究明确了棉花产量育种的主攻方向,为提高棉花选择育种效率和实现高产提供理论指导。     

建国以来我国黄淮棉区棉花品种的遗传改良Ⅰ. 产量及产量组分的改良

本文是我国黄淮棉区棉花品种遗传改良和系列研究之一, 目的在于探讨建国以来我国黄淮棉区棉花品种在产量和产量组分性状(株铃数、 铃重、 衣分)上的遗传改良成效。 对不同历史时期10个代表性品种2年5点的试验资料和30多年的区域试验资料的研究表明, 建国以来, 我国黄淮棉区棉花品种产量性状的遗传改良成效显著, 品种的产     

Genetic association of yield with its component traits in a recombinant inbred line population of cotton

Lint yield of upland cotton (Gossypium hirsutum L.) is determined by its component traits, boll number, boll weight, and lint percentage. Selecting high yielding lines is based on the ability to manipulate component traits. In this study, 188 recombinant inbred lines and two parental lines were grown in 1999 and 2000 at Mississippi State University. Lint yield and its three component traits were measured and analyzed by an extended conditional mixed linear model approach. Boll number unit-area^–1 made the largest contribution to genotypic and genotype × environment (G × E) variations for lint yield. Both boll number and lint percentage, and boll number and boll weight jointly accounted for more than 70% of the genotypic and G × E variations in lint yield. Ninety-nine percent of the genetic and phenotypic variation in lint yield could be explained by the three component traits, indicating that lint yield was mainly dependent on its three component traits. Small phenotypic variation in lint yield could be accounted for by effects of genotype, G × E interactions of boll number or boll number combined with other component trait(s) (Table 5). For boll number unit-area^–1 a wider distribution of genotypic contribution effects was detected than for lint percentage and boll weight in this study. Boll number and boll weight interacted to affect lint yield, indicating that balanced selection for boll weight and boll number is needed in high-yielding line development. Comparative results with other approaches were also discussed in this study.The U.S. Governments right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged     

干旱胁迫对彩色棉花农艺、品质性状及水分利用效率的影响

为了探索干旱胁迫对彩色棉花主要性状的影响及其水分利用机理,选用7个不同色彩的棉花品种(系),在常规灌溉、胁迫灌溉和生育期不灌溉3种环境条件下,调查其农艺性状、品质性状、水分利用效率(WUE)及产量。结果表明,干旱胁迫下不同色彩棉花品种的单株成铃数、单铃重、株高、花铃期叶片数、有效果枝数、收获指数、果节数、籽指、茎粗和果茎节间长度减少,衣分增加;灌水量减少一半,参试棉花品种的产量均降低,不灌溉处理的籽棉产量与常规灌溉间差异显著(P<0.05);籽棉产量的降低幅度品种间存在较大差异(P<0.05),棕色棉的减产幅度高于绿色棉。常规灌溉处理下,白色棉花水分利用效率高于棕色棉花和绿色棉花,而后二者差异不显著;干旱胁迫下,棕色棉花的水分利用效率高于绿色棉花。与水分利用效率相关的主要农艺性状、品质指标是：叶片数、单株成铃数、有效果枝数、果节数、株高、收获指数、单铃重、主茎节间长度、茎粗、籽指、衣分。     

Genetic association of cotton yield with its component traits in derived primitive accessions crossed by elite upland cultivars using the conditional ADAA genetic model

Boll number, lint percentage, and boll weight are three component traits for lint yield of upland cotton, Gossypium hirsutum L. Selecting high yielding lines or hybrids depends on the ability to dissect the genetic relationship of lint yield with these component traits. In this study, 14 day-neutral lines with desirable fiber quality derived from primitive accessions were top crossed with five commercial cultivars. The F₂ populations and parents were grown in one location in 1998 and two locations in 1999 at Mississippi State, MS. The F₃ populations and parents were grown in two locations in 2000. Lint yield and three component traits were measured and analyzed by the ADAA genetic model with the mixed model based conditional approach. Results showed that boll number or boll number with lint percentage or boll weight contributed to the majority of the phenotypic variance and variance components for lint yield. Boll number was more important than the other two component traits in terms of various genetic effects. The results also showed that the combination of boll number and boll weight greatly increased the contribution to lint yield even though boll weight itself had no significant contribution to lint yield compared to boll number alone. The genetic contribution effects were also predicted due to single component traits or their combinations for parents and crosses. The results revealed that the balanced selection of boll weight and boll number should be considered to obtain high yielding hybrids or pure lines. Contribution of the USDA-ARS in cooperation with the Mississippi Agric. and Forestry Exp. Stn. Mention of trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by USDA, ARS and does not imply its approval to the exclusion of other products or vendors that may also be suitable.     

液体地膜对棉花成铃与产量的影响

研究了液体地膜对棉花成铃及产量的影响。结果表明：液体地膜覆盖使棉铃干物质积累加快,铃重有所提高;成铃时空分布合理,烂铃减少,优质铃增加,具有明显的增产效果。其中l12．5kg/hm^2处理最佳,增产皮棉15％。     

2005—2012年新疆南疆棉区棉花杂交种主要经济性状优势分析

研究杂交棉在高密度植棉模式下主要经济性状优势,为新疆南疆棉区棉花杂交种利用提供理论依据。利用2005—2012年南疆中早熟杂交棉和常规陆地棉区域试验品系和审定品种的皮棉产量、纤维品质性状的多年多点数据,进行整理和对比分析。在高密度膜下滴灌种植模式下,杂交棉参试组合经历了起步-快速发展-急速下降的过程。杂交棉参加区试组合在单株铃数、单铃重、衣分变幅较大。陆陆杂交棉组合平均皮棉产量略高于常规陆地棉,纤维长度、比强度等品质指标略低于常规陆地棉,但均不显著。陆陆杂交棉审定品种在单株结铃、单铃重方面显著高于常规陆地棉,但每公顷铃数较常规陆地棉低3.0万个,平均皮棉产量差异不显著。陆海杂交种在单株铃数、纤维品质、抗病性等总体优于陆陆杂交种和常规棉,但在单铃重、衣分、皮棉产量平均分别低于常规陆地棉27.0%、11.3%、7.0%。在目前高密度植棉模式下,参试杂交棉组合较常规陆地棉生产优势并不明显,继续开展高密度强优势杂交棉育种及种植模式研究非常必要。     

棉花产量结构模型的研究

经过1987和1988两年在河南安阳和江苏扬州二个点的田间试验研究,分别建立了棉花纤维产量构成因素公顷铃数、单铃重和衣分对产量影响的数学模型,以及播期、追施氮肥、密度、喷缩节安、去早蕾、留果枝数等栽培措施对产量构成各因素影响的数学模型。分析指出,产量构成因素的重要地位随地区不同而变化,主要栽培措施是依据一定地区和一定年份而言的。在安阳地区,铃重是影响产量最重要的因素,而去早蕾、密度和追施氮肥又是影响铃重的主要栽培措施,这三项措施的重要性顺序随着年份不同而不一样;在扬州地区,公顷铃数是贡献于产量的最重要因素,而密度又是影响公顷铃数的关键栽培措施,留果枝数和追施氮肥的地位则因年份不同而分别居第二、第三位。这为棉花生产因地因时制宜,抓主要矛盾提供了科学依据。