利用回交结合Wx基因分子标记培育部分糯性小麦(英文)

Improvement for Agronomic Traits of Partial Waxy Wheat by Combination of Backcrossing with a PCR-based DNA Marker

颗粒结合型淀粉合成酶Ⅰ(GBSSI,Waxy蛋白)是小麦胚乳中直链淀粉合成的关键酶。小麦基因组中存在3个Waxy基因(Wx-A1、Wx-B1、Wx-D1)。在白火麦中Wx-D1位点的突变(Wx-D1b)引起Wx-D蛋白的缺失,导致直链淀粉含量下降,其面粉表现出部分糯性。与目前生产上推广品种相比,白火麦的农艺性状较差,产量非常低。为了培育农艺性状优良的部分糯性小麦,我们将白火麦与具有优良农艺性状的小麦品种PH85-16、济南17和烟农15(轮回亲本)分别进行杂交,后代分别与相应的三个轮回亲本回交五代,在每代中均选择农艺性状与轮回亲本相近并含有Wx-D1b的后代。在第六代自交后选择具有Wx-D1b的纯合体,选出的单株连续自交三代。获得了六个农艺性状与轮回亲本相似的品系,它们均携带纯合的Wx-D1b位点。研究表明采用回交的方法并结合基于Wx基因序列的分子标记技术,是培育优良部分糯性小麦的一种非常有效的方法。本研究培育出的部分糯性小麦品系可以直接用于大田生产。

To improve agronomic traits of partial waxy wheat, crossing between Chinese Baihuomai and wheat cultivars PH85-16, Jinan 17, and Yannong 15 was performed. The progeny plants were further backcrossed to these cultivars as recurrent parents for five generations. To get homozygous plants with the null allele at the Wx-D1 locus, self-pollination was carried out in the BC5F1 generation. Through another three generations, 6 partial waxy wheat lines were obtained, which had similar agronomic performance as their recurrent parents and carried the null allele at the Wx-D1 locus. In each generation, the Wx-D1 locus was identified by a PCR-based DNA marker and the agronomic traits were examined in progeny plants. The results from this study indicate that the use of backcrossing with a PCR-based DNA marker was useful in waxy wheat breeding. These partial waxy wheat lines can be used in field production.