转W16小麦抗旱新品系的创制及抗旱生理机制分析

摘要

[目的]培育抗旱转基因小麦新品系,解析转基因小麦抗旱生理机制,为转基因小麦抗旱性鉴定提供依据.[方法]以转W16基因3个高代转基因小麦品系为供试材料,在2008-2010年连续两年大田正常灌溉和干旱处理条件下,对转基因小麦品系进行田间抗旱性鉴定；同时对不同生育期植株体内的脯氨酸和可溶性糖含量及其旗叶的SPAD值进行测定分析,[结果]在干旱胁迫条件下,转基因品系比对照济麦19的单株粒重和千粒重极显著增加,其中单株粒重分别增加20.00％-23.08％、20.88％-24.71％和15.29％-25.27％;千粒重分别增加16.24％-19.85％、13.46％-16.95％和21.58％-24.46％.在正常灌溉条件下,单株粒重分别显著增加7.04％-11.11％、3.52％-8.73％和8.45％-12.70％;千粒重分别显著增加13.57％-14.97％、9.91％-11.67％和14.17％-14.65％.转基因小麦品系的单株粒重和千粒重的抗旱系数在1.15-1.45,抗旱性为强到极强.对转基因小麦的抗旱生理机制分析发现,在干旱胁迫下转基因小麦的根系总长度、根系表面积和根系总体积均显著增加；在灌浆后期转基因小麦品系脯氨酸和可溶性糖含量及旗叶的SPAD值均显著高于受体济麦19.[结论]W16的过表达改善了转基因小麦品系的根系结构、延长了旗叶功能时期,从而增强了转基因小麦对干旱胁迫的适应能力.%[Objective] The objective of this study is to study the breeding of new drought-resistant varieties and analyze their physiological mechanism, and to provide a theoretical basis for drought-resistant identification of transgenic wheat plants. [ Method] Three stable W16-transgenic lines were used as materials, and drought-resistant identification was done in the field which was compared under irrigation and drought condition from 2008 to 2010. In addition, the contents of proline, souble sugar, and the SPAD value of flag leaf under different growth periods investigated. [ Result ] Under drought stress conditions, the grain weight per plant and the 1000-grain weight of transgenic lines increased significantly by 1% compare with those of the control. The grain weight per plant of transgenic lines increased by 20.00%-23.08%, 20.88%-24.71% and 15.29%-25.27%, respectively, and the 1000-grain weight elevated by 16.24%-19.85%, 13.46%-16.95%, and 21.58%-24.46%, respectively. Under the normal irrigation conditions, the grain weight per plant of the transgenic lines increased significantly by 7.04%-ll.ll%, 3.52%-8.73%, and 8.45%-12.70%, respectively, and the 1000-grain weight elevated by 13.57%-14.97%, 9.91%-11.67% and 14.17%-14.65%, respectively, compared with the control. Drought resistant index (DRI) of the grain weight per plant and the 1000-grain weight of transgenic lines were strong, or even extremely strong (1.15 to 1.45). In addition, the total length, total surface area, and total volume of root system of transgenic lines were significantly increased under drought stress conditions. The contents of proline and soluble sugar, and SPAD value of flag leaf of transgenic lines were much higher than those of the receptor in the late filling stage. [Conclusion] Overexpression of the W16 improved root structure, prolonged functional period of flag leaf, and finally improved the adaptive ability to drought stress in transgenic wheat lines.