Delineation of interspecific epistasis on fiber quality traits in Gossypium hirsutum by ADAA analysis of intermated G. barbadense chromosome substitution lines
Delineation of interspecific epistasis on fiber quality traits in Gossypium hirsutum by ADAA analysis of intermated G. barbadense chromosome substitution lines
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DOI：
10.1007/s00122-011-1536-5
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发表时间：
2011-05-01
影响因子：
5.4
通讯作者：
Stelly, D. M.
中科院分区：
文献类型：
--
作者：
Saha, S.;Wu, J.;Stelly, D. M.
遗传多样性是任何作物改良计划的基础，但栽培最多的高地棉花[Gossypium hirsutum L.，2n = 52，基因组式2（AD）（1）]由于其进化起源和驯化历史，其基因库非常狭窄。该品种（G. hirsutum L.）具有优良的产量、农艺性状和纤维特性，而其它栽培的52染色体种，G.巴巴多斯湖[2n= 52，基因组式2（AD）（2）]，被广泛认为具有相反的属性。它具有非常好的纤维品质，但通常产量较低，农艺性状不理想。育种者一直渴望联合收割机G.棉和但成功有限。F-1杂种很容易产生，并且很大程度上是可育的，因此有限的成功可能是由于与种间渐渗的常规方法相关的神秘的生物学和技术挑战。我们已经开发了一种互补的替代方法渗入的基础上，染色体置换线，随后越来越复杂的染色体衍生的家庭的遗传分析，以描述的遗传和育种价值的染色体置换线。在这里，我们分析了纤维品质性状的后代家庭从部分双列杂交方案之间选择的染色体代换系（CS-B系）。结果提供了一个更详细和精确的QTL解剖纤维性状，并有机会检查两个替代染色体与一个替代染色体之间的等位基因互作效应。该方法基于准等基因染色体置换的成对组合来创建新种质。两条染色体相互作用的相对遗传简单性与复杂的或基于RIL的群体显著不同，在复杂的或基于RIL的群体中，大量的基因座在所有26条染色体对中分离。数据进行了分析，根据ADAA遗传模型，揭示了显着的加性，显性和加性上位性效应与CS-B系的染色体或染色体臂取代的所有纤维品质性状。在所有亲本和杂交种中，代换染色体供体亲本3-79的纤维具有最高的上半平均长度（UHM）、整齐度比、强度、伸长率和最低的马克隆值。CS-B16和CS-B25对各纤维性状的加性效应均达极显著水平。在假定CS-B系遗传背景一致的情况下，对双杂合杂交组合（CS-B × CS-B）与单杂合组合（CS-B × TM-1）的比较分析表明，染色体上基因间的上位效应对大多数纤维品质性状起主要作用。结果表明，CS-B16 × CS-B22 Lo、CS-B16 × CS-B25和CS-B16 × TM-1的纤维伸长显性效应均显著大于亲本，CS-B16 × CS-B17的纤维比强度显著高于亲本。与大多数代换染色体和染色体臂相关的纤维品质性状也存在多重拮抗遗传效应。本研究的结果突出了上位性在纤维品质性状中的重要性，并检测到了3-79染色体上一些影响纤维品质的隐性有益等位基因的新效应，这些效应在3-79亲本系中未检测到。
Genetic diversity is the foundation of any crop improvement program, but the most cultivated Upland cotton [Gossypium hirsutum L., 2n = 52, genomic formula 2(AD)(1)] has a very narrow gene pool resulting from its evolutionary origin and domestication history. Cultivars of this cotton species (G. hirsutum L.) are prized for their combination of exceptional yield, other agronomic traits, and good fiber properties, whereas the other cultivated 52-chromosome species, G. barbadense L. [2n = 52, genomic formula 2(AD)(2)], is widely regarded as having the opposite attributes. It has exceptionally good fiber qualities, but generally lower yield and less desirable agronomic traits. Breeders have long aspired to combine the best attributes of G. hirsutum and G. barbadense, but have had limited success. F-1 hybrids are readily created and largely fertile, so the limited success may be due to cryptic biological and technical challenges associated with the conventional methods of interspecific introgression. We have developed a complementary alternative approach for introgression based on chromosome substitution line, followed by increasingly sophisticated genetic analyses of chromosome-derived families to describe the inheritance and breeding values of the chromosome substitution lines. Here, we analyze fiber quality traits of progeny families from a partial diallel crossing scheme among selected chromosome substitution lines (CS-B lines). The results provide a more detailed and precise QTL dissection of fiber traits, and an opportunity to examine allelic interaction effects between two substituted chromosomes versus one substituted chromosome. This approach creates new germplasm based on pair wise combinations of quasi-isogenic chromosome substitutions. The relative genetic simplicity of two-chromosome interactions departs significantly from complex or RIL-based populations, in which huge numbers of loci are segregating in all 26 chromosome pairs. Data were analyzed according to the ADAA genetic model, which revealed significant additive, dominance, and additive-by-additive epistasis effects on all of the fiber quality traits associated with the substituted chromosome or chromosome arm of CS-B lines. Fiber of line 3-79, the donor parent for the substituted chromosomes, had the highest Upper Half Mean length (UHM), uniformity ratio, strength, elongation, and lowest micronaire among all parents and hybrids. CS-B16 and CS-B25 had significant additive effects for all fiber traits. Assuming a uniform genetic background of the CS-B lines, the comparative analysis of the double-heterozygous hybrid combinations (CS-B x CS-B) versus their respective single heterozygous combinations (CS-B x TM-1) demonstrated that interspecific epistatic effects between the genes in the chromosomes played a major role in most of the fiber quality traits. Results showed that fiber of several hybrids including CS-B16 x CS-B22Lo, CS-B16 x CS-B25 and CS-B16 x TM-1 had significantly greater dominance effects for elongation and hybrid CS-B16 x CS-B17 had higher fiber strength than their parental lines. Multiple antagonistic genetic effects were also present for fiber quality traits associated with most of the substituted chromosomes and chromosome arms. Results from this study highlight the vital importance of epistasis in fiber quality traits and detected novel effects of some cryptic beneficial alleles affecting fiber quality on the 3-79 chromosomes, whose effects were not detected in the 3-79 parental lines.