转基因抗丝黑穗病玉米的遗传、表达及选育研究

本研究以几丁质酶基因导入玉米自交系海92-1所获得的转基因植株的种子作为试验材料,对其To代种子进行了潮霉素抗性筛选试验,结果表明T1代的分离比分别为3:1和15:1(表1).这证实大多数转基因植株中几丁质酶基因是以单拷贝、单位点整合到植株的基因组中,个别转基因植株中是以单拷贝、多位点整合到转基因植株的基因组中的.农艺性状调查分析,转基因株系的株高和穗位高都高于对照植株,单株结穗数基本不变,而转基因植株的穗长值和穗粒数值均比对照植株大,穗长增加4～7 cm,穗粒数增加1%～7%.对T1,T2,T3代株系的PCR检测结果说明目的基因在转基因植株中可稳定遗传.田间抗病鉴定结果显示,转基因株系的发病率比当代对照株系明显减少2～4级,选育得到的纯合系06006和06012的发病率为0,表现出高抗病性.

Studies on Inheritance, Expression and Selection Breeding of Resistance to Head Smut in Transgenic Maize

In this study, the transgenic seeds used as experiment material were obtained from head smut-resistant transgenic maize lines that transformed by pollen- mediated approach on inbred line Hai 92-1. Partly T0 seeds were subjected to hygromycin- screening, the results appeared that the segregation ratio of majority of T1 transgenic lines for hygromycin-resistant and susceptible was 3:1, minority of T1 lines were 15:1. Further analysis suggested that single copy of the chitinase gene was integrated into the genome of most T0 transgenic plants, and a few of transgenic plants contained more than one copy of the gene. Investigation results of transgenic plants on agronomic characters showed: firstly the plants height of transgenic lines were higher than that of control plants; secondly the era number per transgenic plant was as much as that of control; and next the ear length and Kernels / ear of transgenic lines were increase much than that of control plants, the degree of increase were 4~7 cm and 1%~7%, respectively. The PCR analysis for T1, T2, and T3 progenies indicated that chitinase gene can stablely inherited. Investigation results of disease incidence of transgenic lines included: the disease incidence of transgenic lines was 2~4 degree lower than CK lines. The disease incidence of lines 06006 and 06012 obtained from T3 generation transgeneic line by selection breeding.