玉米×四倍体多年生玉米杂种F_2非整倍体研究

Study on Introgression of Z. perennis Genome into Maize

【目的】四倍体多年生玉米(Z.perennis,2n=40)是玉米(Z.mayL,2n=20)的一个野生近缘材料,具有耐寒、耐旱、高抗多种病害等优良特性。本研究目的是探讨如何将四倍体多年生玉米优良遗传物质导入到玉米中,合成含有四倍体多年生玉米遗传物质的玉米遗传种质,拓展、创新玉米种质遗传基础。【方法】本研究用遮光调节开花时期、人工辅助杂交等措施,从四倍体多年生玉米与二倍体种(2n=20)种间杂交F1(2n=30)获得杂种F2,对F2进行形态学、细胞学观察,及SSR比较研究,并利用非整倍体F2为桥梁转育四倍体多年生玉米优良遗传物质导入到玉米中。【结果】各F2植株形态特征变化较大,获得的10株F2植株中,有6株野生亲本型植株,2株中间型植株,2株玉米型植株;它们的体细胞数目分别为24、25、26条,其中25条的频率较高;SSR标记鉴定结果表明,在10株F2中大多还保留有玉米第1,7,8,9,10染色体,而第2,3,4,5,6染色体易于在F2中消除。【结论】利用玉米野生近缘材料远缘杂交后代具有光敏反应的特点,可以获得玉米与四倍体多年生玉米杂种F2非整倍体材料,这些F2非整倍体是四倍体多年生玉米遗传物质转移到玉米育种中的桥梁材料。

[Objective] Zea perennis is a wild relative of maize with 2n=40. It contains a number of novel genes and traits, such as resistance to economically important diseases and pests. Perennial teosinte is a potential new gene source for maize improvement. The aim of this study is how to transfer desirable good traits from Z. perennis into maize. [ Method ] The F1 of maize×Z. perennis has genomic affinities, but few F2 individuals of maize×Z. perennis could be obtained by some special treatments, and the F2 can be used as one kind of bridge to be transferred desirable good traits from Z. perennis to maize. [Result] In this study, morphologic, cytological and SSR observation on F2 were conducted. Results showed that 10 F2 plants have different plant types such as wild parent-like, intermediate type, and maize-like. These F2 cells had 24, 25 and 26 chromosome number, which were aneuploids. Due to maize×Z. perennis （2n=30） plant with the most （requent configuration of 5Ⅲ＋5Ⅱ＋5Ⅰ, which produced the chromosome elimination for aneuploids. The SSR assay further confirmed that maize chromosome 2, 3, 4, 5, 6 were easy to be eliminated than maize chromosome 1,7, 8, 9, 10. [ Conclusion ] Few F2 individuals of maize×Z. perennis could be obtained by some special treatments, the F2 generation was aneuploid, and those F2 generation could be used as a bridge to transfer desirable good traits from Z. perennis to maize.