CIMMYT新型人工合成小麦Pina和Pinb基因等位变异  

Allelic Variations of Puroindoline a and Puroindoline b Genes in New Type of Synthetic Hexaploid Wheats from CIMMYT

作　　者：李根英[1] 夏先春[2] 何中虎[2] 孙其信[1] 

机构地区：[1]中国农业大学农学与生物技术学院,北京100094 [2]中国农业科学院作物科学研究所国家小麦改良中心/国家农作物基因资源与基因改良重大科学工程,北京100081

出　　处：《作物学报》2007年第2期242-249,共8页Acta Agronomica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2002CB101300)

摘　　要：八倍体人工合成小麦由硬粒小麦（Triticum turgidum subsp．durum）与粗山羊草（Aegilops tauschii Coss．）杂交产生，是研究小麦进化过程中基因变异的重要材料。以国际玉米小麦改良中心（CIMMYT）提供的57份由野生二粒小麦（T．turgidum subsp．dicoccoides）与粗山羊草杂交产生的新型人工合成六倍体小麦为材料，用单籽粒特性测定仪和Pina、Pinb特异性PCR引物对其籽粒硬度变异以及控制籽粒硬度的主效基因Pina和Pinb的分布情况进行了研究。结果表明，这些材料的SKCS硬度值变异较大，从10．5到42．6，其中15-30的占78％。共有Pina-Dla、Pina-Dlc、Pinb-Dlh和Pinb-Dlj4种等位变异型，基因型为Pina-Dla／Pinb-Dlj的8个，占14％；基因型为Pina-Dlc／Pinb-Dlh的49个，占86％。方差分析表明，基因型Pina-Dla／Pinb-Dlj与Pina-Dlc／Pinb-Dlh对籽粒硬度的影响差异不显著，但父本粗山羊草和母本野牛二粒小麦以及二者间的互作对籽粒硬度有显著影响，说明除Pina和Pinb外，还有其他微效基因影响籽粒硬度的形成。Triticum dicoccoides and Aegilops tauschii are important germplasm resources of rich genetic variability for improvement of hexaploid wheat （ T. aestivum ）. This variability can be accessed by utilizing synthetic hexaploid wheat lines with genomes from Ae. tauschii and T. dicoccoides. Two methods can be employed to incorporate Triticum dicoccoides and Aegilops tauschii genes into a hexaploid wheat. One is the direct cross method of hybridization between Ae. tauschii and hexaploid wheat, another is an indirect method of synthetic hexaploids by crossing tetraploid wheat with Ae. tauschii. Genes from tetraploid wheat and Aegilops tauschii are then available via direct crossing of synthetic hexaploids to T. aestivum. The CIMMYT （International Maize and Wheat Improvement Center） has produced two types of synthetic hexaploids. One is the progeny of T. turgidum ssp. durum crossing with Ae. tauschii, another is the new type synthetic wheat which produced by crossing Triticum dicoccoides with Aegilops tauschil. Grain hardness is a major factor influencing the end-use quality. Genes for grain hardness in common wheat reside on Ha locus of chromosome 5DS. The wild-type alleles （Pina-Dla, Pinb-Dla） determine soft endosperm, while the hard phenotypes result from mutations in either Pina or Pinb. In order to understand the evolution of genes for grain hardness, studies have focused on the wild relatives of common wheat, particularly on Ae. tauschii, the supposed donor of the D genome in common wheat. Puroindoline a in Ae. tauschii contained 99.3 % amino acid sequence homology to the wheat cultivar ‘Penawawa＇ and 90.5% amino acid sequence homology in puroindoline b. Among 50 Ae. tauschii accessions, four alleles of puroindoline a and four alleles of puroindoline b were identified, encoding two and three different proteins, respectively. However, the effect that these sequence polymorphisms may have on kernel texture is unknown, as no test method of texture has been developed for Ae. tauschii. The incorporatio

关 键 词：野生二粒小麦 粗山羊草 人工合成小麦 Pina和Pinb 籽粒硬度 

分 类 号：S512.1[农业科学—作物学]