转基因耐盐玉米自交系的农艺性状及杂种优势表现的分析

Agronomic Traits and Combining Ability Analysis of Salt Enduring Transgenic Maize

【目的】利用转基因技术创造玉米新种质已成为玉米新技术育种的重要组成部分。为了有效地从玉米转基因植株及其后代中选育出优良自交系及杂交种,深入研究转基因玉米的农艺性状及杂种优势表现是十分重要的。【方法】以转betA(来自大肠杆菌的胆碱脱氢酶基因)的玉米优良自交系DH4866纯合系为材料,进行农艺性状和杂种优势表现分析。【结果】发现转基因纯合系植株及其杂交种具有明显提高的耐盐性,在含盐量较高的土地中转基因植株杂交组合的产量大幅度高于受体自交系配制的杂交组合。在不同含盐量的土地中,来自不同独立转化体的转基因植株多数保持受体自交系的基本特征,但部分农艺性状和特殊配合力出现差异,甚至达到差异极显著程度。来自同一转化体的不同转基因株系的植株,农艺性状和特殊配合力的差异一般较小,但单株产量等性状可表现显著差异。在反映经济性状的各参数中,变异幅度大的是单株产量及小区产量,这种差异在T2代和T4代转基因植株配制的杂交种中都存在,由独立转化体的遗传基础差异产生。【结论】在以玉米自交系为受体的转基因育种中,加强早期时代的定向检测和配合力测定,能够较快地获得转基因玉米优良杂交种。

【Objective】Agronomic traits and combining ability study of transgenic plants is important for obtaining an elite inbred lines and hybrids efficiently from maize transgenic plants or progenies. 【Method】Transgenic homogenous lines were obtained by introduction of betA gene encoding choline dehydrogenase from E. coli into maize elite inbred line DH4866. 【Result】 The transgenic homogenous lines and hybrids coming from the lines showed significantly improved salt-tolerance. In saline soil the yields of transgenic hybrids were much higher than those of the recipient inbred line DH4866. In soils containing various concentrations of NaCl, though most of the transgenic plants from different transgenic events maintained basic characters of the recipient inbred line, but a part of them showed variance in some agronomic traits and special combining ability and few showed significant differences. The differences of agronomic traits and special combining ability between plants coming from different lines of single transgenic event were generally not significant, but some traits, including the yield per plant, showed significant difference. Out of the economic traits, the per plant yield and per plot yield showed more obvious variances and this variance maintained in hybrids from T2 to T4 generation, suggesting the variance derived from the genetic variance of the transgenic events. 【Conclusion】 It is essential to perform directional selection and combining ability detection during early generations of transgenic lines in order to obtain elite transgenic hybrid earlier.