Quantitative trait loci (QTL) of stem strength and related traits in a doubled-haploid population of wheat (Triticum aestivum L.)
Quantitative trait loci (QTL) of stem strength and related traits in a doubled-haploid population of wheat (Triticum aestivum L.)
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DOI：
10.1007/s10681-005-4713-2
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发表时间：
2005-01-01
期刊：
影响因子：
1.9
通讯作者：
Jia, JZ
中科院分区：
文献类型：
--
作者：
Hai, L;Guo, HH;Jia, JZ
在自然田间条件下，抗倒伏性的评分是困难的。小麦茎秆强度是衡量小麦抗倒伏性的一个指标。然而，这是一个由两个性状组成的复杂性状，即茎的机械弹性和刚度。因此，它与茎的形态解剖特征密切相关。研究小麦茎基部节间强度及相关性状的遗传，对小麦抗倒伏性的遗传改良具有重要意义。在这项研究中，一个双单倍体（DH）群体来自花药培养的杂交CA 9613/1-11488。在乳熟期测定茎强度和相关的基部节间性状。利用189个SSR标记构建了DH群体的分子图谱，并在此基础上对各性状进行了QTL分析。结果表明：（1）在3A和3B染色体上检测到2个控制茎强的QTL（QSs-3 A和QSs-3 B），表型方差分别为10.6%和16.6%; 2)在1A和2D染色体上检测到2个与髓径相关的QTL（QPd-1A和QPd-2D），共解释约30%的表型变异。3)茎粗和秆壁厚分别在3B和2D染色体上检测到1个QTL，其中QSd-3B可解释茎粗表型方差的8.7%，而QCwt-2D可解释秆壁厚表型方差的9.6%。此外，在检测到的QTL中，有两个QTL具有多效性效应。相关性状通常与同一QTL的多效性或不同QTL的连锁有关。但在某些情况下并非如此。QTL定位结果表明，选择茎粗/髓径比大、茎粗宽的品种，可以提高茎秆强度。这可以通过使用与QSd-3B和QCwt-2D连锁的标记来促进。将茎强、茎粗和秆壁厚作为抗倒性的选择指标，结合分子标记辅助选择（MAS），可以提高该群体的抗倒性。
Scoring for lodging resistance is difficult under natural field conditions. The stem strength of wheat has been used as an index of lodging resistance. However, this is a complex trait comprised of two characters, i.e. stem mechanical elasticity and rigidity. Therefore it is closely associated with stem morphological and anatomical features. A study of the genetics of stem strength and related traits of basal stem internodes is very important for genetic improvement of lodging resistance in wheat. In this study, a doubled-haploid (DH) population derived from anther culture of the cross CA9613/1-11488 was used. Stem strength and related basal internode traits were measured at the milk stage. A molecular map of the DH population was constructed using 189 SSR markers, and quantitative trait loci (QTL) for each trait were analyzed based on this molecular linkage map. A total of six QTL for stem strength, culm wall thickness, pith diameter and stem diameter were identified: 1) Two QTL (QSs-3 A and QSs-3 B) for stem strength were detected on chromosomes 3A and 3B, exhibiting 10.6 and 16.6% phenotypic variance, respectively. 2) Two QTL (QPd-1A and QPd-2D) associated with pith diameter were detected on chromosomes 1A and 2D, respectively, jointly explaining about 30% of phenotypic variance. 3) As far as stem diameter and culm wall thickness were concerned, one QTL was detected on chromosomes 3B and 2D, respectively; QSd-3B explained 8.7% of the phenotypic variance of stem diameter, whereas QCwt-2D explained 9.6% of the phenotypic variance of culm wall thickness. In addition, among the QTLs detected, two with pleiotropic effects were observed. Correlated traits are usually associated with the pleiotropic effects of the same QTL(s) or linkage of different QTLs. But this was not true in some cases. The results of QTL mapping showed that stem strength can be improved by breeding for wider stems with a higher stem diameter/pith diameter ratio. This can be facilitated by using the markers linked to QSd-3B and QCwt-2D. Combining stem strength, stem diameter and culm wall thickness may be used as a selection index for lodging resistance with marker-assisted selection (MAS) to improve lodging resistance in this population.