Identification of genetic loci affecting amylose content and agronomic traits on chromosome 4A of wheat
Identification of genetic loci affecting amylose content and agronomic traits on chromosome 4A of wheat
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DOI：
10.1007/s001220051158
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发表时间：
1999-05-01
影响因子：
5.4
通讯作者：
Sawada, S
中科院分区：
文献类型：
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作者：
Araki, E;Miura, H;Sawada, S
小麦4A染色体携带Wx-B1基因，该基因编码与胚乳中直链淀粉合成有关的颗粒结合淀粉合成酶。为了明确该位点的多效性效应和独立QTL对农艺性状的影响，利用中国春与中国春杂交后代（Kanto 107 4A）获得的98个单染色体重组代换系进行了4A染色体的遗传分析。直链淀粉含量的遗传变异主要由Wx-B1位点的等位基因差异引起。在短臂上的6.2-cM Xbcd 1738/Xcdo 1387区间定位了一个额外的次要效应QTL，其中来自Kanto 107的等位基因导致直链淀粉含量增加。两个季节的田间试验揭示了Wx-B1的多效性效应，或者说是一个紧密连锁的QTL对穗发芽时间的影响。检测到一个与Wx-B1连锁的株高QTL。对于植物产量及其组成部分，没有证据表明Wx-B1或邻近地区存在显着的主效应。利用RFLP标记在短臂上定位到一个产量QTL，与控制穗粒数和穗粒重的QTL一致。在这些农艺性状的QTL上，来自Kanto 107的等位基因有助于提早出苗、降低株高和提高产量。
Chromosome 4A of wheat carries the Wx-B1 gene encoding the granule-bound starch synthase involved in amylose synthesis in the endosperm. To determine the pleiotropic effects of this locus and effects of independent QTLs on agronomic traits, genetical analysis of chromosome 4A was conducted using 98 single-chromosome recombinant substitution lines derived from a cross of Chinese Spring and Chinese Spring (Kanto107 4A) with a low amylose content due to the null Wx-Blb allele. For amylose content, most of the genetic variation was explained by the allelic difference at the Wx-B1 locus. An additional QTL of minor effect was mapped in the 6.2-cM Xbcd1738/Xcdo1387 interval on the short arm, where the allele from Kanto107 led to an increase in amylose content. Field trials over two seasons revealed a pleiotropic effect of Wx-B1, or else the effect of a closely linked QTL, on ear emergence time. A QTL linked to Wx-B1 was detected for plant height. For plant yield and its components, there was no evidence for significant main effects associated with Wx-B1 or adjacent regions. One plant-yield QTL was identified by RFLP markers on the short arm and this was identical to QTLs controlling spikelet number/ear and grain weight/ear. At these QTLs for agronomic traits, alleles from Kanto107 contributed to an earlier emergence time, a height reduction and an yield increase.