Key Laboratory of Crop Germplasm and Biotechnology, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
New Phytol. 2010 Feb;185(3):841-51. doi: 10.1111/j.1469-8137.2009.03099.x. Epub 2009 Dec 1.
Ppd-D1 is one of the most potent genes affecting the photoperiod response of wheat (Triticum aestivum). Only two alleles, insensitive Ppd-D1a and sensitive Ppd-D1b, were known previously, and these did not adequately explain the broad adaptation of wheat to photoperiod variation. In this study, five diagnostic molecular markers were employed to identify Ppd-D1 haplotypes in 492 wheat varieties from diverse geographic locations and 55 accessions of Aegilops tauschii, the D genome donor species of wheat. Six Ppd-D1 haplotypes, designated I-VI, were identified. Types II, V and VI were considered to be more ancient and types I, III and IV were considered to be derived from type II. The transcript abundances of the Ppd-D1 haplotypes showed continuous variation, being highest for haplotype I, lowest for haplotype III, and correlating negatively with varietal differences in heading time. These haplotypes also significantly affected other agronomic traits. The distribution frequency of Ppd-D1 haplotypes showed partial correlations with both latitudes and altitudes of wheat cultivation regions. The evolution, expression and distribution of Ppd-D1 haplotypes were consistent evidentially with each other. What was regarded as a pair of alleles in the past can now be considered a series of alleles leading to continuous variation.
Ppd-D1 是影响小麦光周期反应的最主要基因之一。先前只知道两个等位基因，不敏感的 Ppd-D1a 和敏感的 Ppd-D1b，但它们不能充分解释小麦对光周期变化的广泛适应。在这项研究中，使用了五个诊断分子标记来鉴定来自不同地理位置的 492 个小麦品种和小麦的 D 基因组供体物种节节麦的 55 个品系中的 Ppd-D1 单倍型。鉴定出了六个 Ppd-D1 单倍型，分别命名为 I-VI。类型 II、V 和 VI 被认为更古老，而类型 I、III 和 IV 则被认为是从类型 II 衍生而来的。Ppd-D1 单倍型的转录丰度表现出连续变化，以单倍型 I 最高，单倍型 III 最低，与抽穗时间的品种差异呈负相关。这些单倍型也显著影响其他农艺性状。Ppd-D1 单倍型的分布频率与小麦种植区的纬度和海拔高度呈部分相关。Ppd-D1 单倍型的进化、表达和分布彼此一致。过去被认为是一对等位基因的现在可以被认为是一系列导致连续变化的等位基因。
