烟草抗CMV细胞突变系筛选系统的研究

A TECHNICAL SYSTEM FOR SCREENING OF TOBACCO SOMATIC CELL MUTANT RESISTANT TO CMV

在单倍体烟草6叶期接种CMV,接种前3d适当增施氮肥,接种后置28±2℃和自然光照条件下最适合CMV侵染和发病,发病后烟苗仅9或10位叶全部畸型褪绿,这是用绿岛法筛选抗CMV细胞突变系的临界选择压。用0.3％EMS(硫酸二乙酯)诱变烟苗心叶,接种CMV后置临界选择条件下从普通烟草良种Burley18的928个病株中选到每叶仅1～2个绿岛的畸型褪绿叶78片。截取绿岛进行组织培养得到146株无病试管苗,移栽盆钵后再接种CMV鉴定,选到抗CMV突变系R_2和R_8,其当代无性系在夏季网室条件下病情指数较亲本低40.1～45.3,并能通过有性过程传递。

The haploid tobacco seedlings were inoculated with CMV at six-leaf stage. Nitrogen fertiliser was applied to the seedlings 72h prior to inoculation. The inoculated seedlings were put in green house at 28±2℃ under natural lighting. This is the optimal condition for the infection and the disease of TMV. The 9th or 10th leaf of diseased tobacco seedlings was completely abnormal or chlorisis. This was considered the critical selection pressure for the screen of CMV-resistance mutants by the method of culturing dark green island. The heart leaves of tobacco seedlings were mutagenized with 0. 3% EMS. The seedlings were laid under critical selection pressure after inoculation. Seventy-eight abnormal or chlorisis leaves, which had only one to two green islands, were selected from 928 diseased seedlings of Burley 18. The green islands were sectioned and cultured on medium. 146 health test tube seedlings were obtained. The health seedlings were transplanted and inoculated with CMV. The resistance mutant lines R2 and R8 were selected. The disease indices of them were 40.1 - 45. 3 lower than that of the parent. The characteristics of the CMV resistance could be hereditary in the reproductive period.