Ppd-B1 and Ppd-D1 and their effects in southern Australian wheat
Ppd-B1 and Ppd-D1 and their effects in southern Australian wheat
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DOI：
10.1071/cp13086
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发表时间：
2013-01-01
影响因子：
1.9
通讯作者：
Martin, P. J.
中科院分区：
文献类型：
--
作者：
Cane, Karen;Eagles, H. A.;Martin, P. J.
光周期和春化基因对小麦适应多变的环境非常重要。此前，我们利用诊断标记以及来自澳大利亚南部的一个大型非平衡数据集，估算了Vrn - A1、Vrn - B1和Vrn - D1的常见等位基因以及Ppd - D1的两种等位基因类型对抽穗天数的影响。这些基因对该性状的基因型方差的贡献率约为45%。现在我们将这些分析扩展到Ppd - D1的其他等位基因以及与拷贝数相关的Ppd - B1的四个等位基因。在我们的群体中出现了Ppd - B1拷贝数的变异，存在1到4个连锁拷贝。此外，在极少数情况下，Ppd - B1基因缺失（无效等位基因）。我们标记为Ppd - B1b的单拷贝等位基因和标记为Ppd - B1a的三拷贝等位基因在一个世纪的小麦育种过程中出现，并且仍然常见。由于有几个不同的祖先，单拷贝等位基因可能不是同质的。我们标记为Ppd - B1d的双拷贝等位基因通常是从WW15（又名Anza）引入的，而标记为Ppd - B1c的四拷贝等位基因来自中国春小麦。在成对比较中，Ppd - B1a和Ppd - B1c减少了抽穗天数，而Ppd - B1d增加了抽穗天数。在现代澳大利亚种质中，具有启动子缺失的Ppd - D1a、外显子7缺失的Ppd - D1d以及完整等位基因Ppd - D1b较为常见。在我们的田间条件下，Ppd - D1a和Ppd - D1d在抽穗天数上的差异取决于春化基因的等位基因，这证实了我们之前关于这类基因之间存在大量上位性相互作用的报告。Ppd - D1b等位基因赋予了一种光周期反应，这可能有助于从不同播种日期培育出更接近最佳抽穗日期的品种。纳入Ppd - B1基因型以及对Ppd - D1更精确的解析，使归因于这些春化和光周期基因的基因型方差比例增加到约53%。
Photoperiod and vernalisation genes are important for the adaptation of wheat to variable environments. Previously, using diagnostic markers and a large, unbalanced dataset from southern Australia, we estimated the effects on days to heading of frequent alleles of Vrn-A1, Vrn-B1, and Vrn-D1, and also two allelic classes of Ppd-D1. These genes accounted for similar to 45% of the genotypic variance for that trait. We now extend these analyses to further alleles of Ppd-D1, and four alleles of Ppd-B1 associated with copy number.Variation in copy number of Ppd-B1 occurred in our population, with one to four linked copies present. Additionally, in rare instances, the Ppd-B1gene was absent (a null allele). The one-copy allele, which we labelled Ppd-B1b, and the three-copy allele, which we labelled Ppd-B1a, occurred through a century of wheat breeding, and are still frequent. With several distinct progenitors, the one-copy allele might not be homogenous. The two-copy allele, which we labelled Ppd-B1d, was generally introduced from WW15 (syn. Anza), and the four-copy allele, which we labelled Ppd-B1c, came from Chinese Spring. In paired comparisons, Ppd-B1a and Ppd-B1c reduced days to heading, but Ppd-B1d increased days to heading.Ppd-D1a, with a promoter deletion, Ppd-D1d, with a deletion in Exon 7, and Ppd-D1b, the intact allele, were frequent in modern Australian germplasm. Differences between Ppd-D1a and Ppd-D1d for days to heading under our field conditions depended on alleles of the vernalisation genes, confirming our previous report of large epistatic interactions between these classes of genes. The Ppd-D1b allele conferred a photoperiod response that might be useful for developing cultivars with closer to optimal heading dates from variable sowing dates. Inclusion of Ppd-B1 genotypes, and more precise resolution of Ppd-D1, increased the proportion of the genotypic variance attributed to these vernalisation and photoperiod genes to similar to 53%.