A major QTL controlling seed dormancy and pre-harvest sprouting/grain α-amylase in two-rowed barley (Hordeum vulgare L.)
A major QTL controlling seed dormancy and pre-harvest sprouting/grain α-amylase in two-rowed barley (Hordeum vulgare L.)
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DOI：
10.1071/ar02210
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发表时间：
2003-01-01
影响因子：
--
通讯作者：
Appelsa, R
中科院分区：
文献类型：
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作者：
Li, CD;Tarr, A;Appelsa, R
大麦种子休眠是由多个基因控制的，这些基因与环境有很强的相互作用。缺乏足够的休眠导致在潮湿的天气条件下收获前在田间发芽。另一方面，太多的休眠对麦芽房有不利影响。啤酒大麦的休眠期只有一个很窄的窗口。哈灵顿大麦是国际市场上的主要制麦品种，也是澳大利亚大麦育种中广泛使用的大麦品种。利用Chebec/哈灵顿杂交的双单倍体（DH）群体寻找与种子休眠和穗发芽相关的分子标记。利用α-淀粉酶活性检测大麦籽粒穗发芽，发现了一个控制穗发芽的主效数量性状位点（QTL），可解释70%以上的表型变异。该QTL位于第5 HL染色体上，两侧分别有限制性片段长度多态性（RFLP）标记CDO 506和简单重复序列（SSR）标记GMS 1。在斯特林/哈灵顿DH群体中进一步验证了与该QTL连锁的SSR标记（GMS 1）。2 H染色体上的一个次要QTL占表型变异的8%。2个控制种子休眠性的QTL位于2 H和5 HL染色体上。休眠性的主效QTL与穗发芽的主效QTL位于第5 HL染色体上，可解释61%的表型变异。由于该位点上的哈灵顿等位基因的存在不仅有利于收获前发芽，而且还增加了麦芽提取物、糖化力、α-淀粉酶和游离氨基酸氮，因此开发具有收获前发芽耐受性的高麦芽品质品种似乎是困难的。
Barley seed dormancy is controlled by multiple genes that have a strong interaction with the environment. Lack of adequate dormancy results in pre-harvest sprouting in the field under wet weather conditions. On the other hand, too much dormancy has a detrimental effect in the malting house. There is only a very 'narrow window' of dormancy for malting barley. Harrington barley, which has been a dominant malting variety in the international market and widely used in Australia barley breeding programs, is highly susceptible to pre-harvest sprouting. A doubled haploid (DH) population derived from a cross of Chebec/Harrington was used to search for molecular markers linked with seed dormancy and pre-harvest sprouting. One major quantitative trait locus (QTL) was identified to control pre-harvest sprouting measured by alpha-amylase activity in barley grains, and could explain > 70% of the phenotypic variation. This QTL was located on chromosome 5HL and flanked by restriction fragment length polymorphism ( RFLP) marker CDO506 and simple sequence repeat (SSR) marker GMS1. The SSR marker (GMS1) linked with this QTL was further validated in a Stirling/Harrington DH population. A minor QTL on chromosome 2H accounted for 8% of phenotypic variation. Two QTLs for seed dormancy were located on chromosomes 2H and 5HL. The major QTL for dormancy coincided with the QTL for pre-harvest sprouting at chromosome 5HL and explained 61% of phenotypic variation. Since the presence of the Harrington allele at this locus favoured not only pre-harvest sprouting, but also increased malting extract, diastatic power, alpha-amylase, and free amino acid nitrogen, development of high malting quality varieties with pre-harvest sprouting tolerance would appear to be difficult.