γ射线对小麦幼胚愈伤组织诱变效应的研究

STUDY ON MUTAGENESIS OF IMMATURE EMBRYO CALLUS TREATED WITH Y RAYS IN WHEAT

用^(60)Coγ射线辐照小麦幼胚愈伤组织,可使愈伤组织分化成苗率达50％左右,适宜剂量为1～1.5krad。利用温室加代,在工年时间内可获得γR_0、γR_1两代种子,γR_0代长势弱,出现植株矮化、穗变小及不育株的变异,但基本不遗传,仅有少数穗形、壳色、芒性、籽粒等变异可遗传。γR_1代株高、穗形、壳色、芒性及籽粒性状都有较大变异,总变异率48％～65％,而未经辐照处理的对照,γR_1代的总变异率为32％～38％。γR_1代是选育优良单株的主要世代。γR_1代的变异性状在γR_2代中有80％趋于稳定,γR_2是选育优良无性系的较好世代。同工酶分析表明,各优良无性系与亲本相比都有其特征酯酶带。

The mutagenic effect of γ radiation on somaclonal variation of immature embryo callus from wheat was investigated.The results showed that 1~1.5 krad was an appropriate exposure dose range which led to a plantlet regeneration rate of irradiated of 50%.Two generations (γR0 and γR1) of the plantlet could be harvested within 1 year with greenhouse culture.Plant grew weakly and variation,such as dwarf plant,small ear and sterile plant,appeared in γR0 generation.There was a high frequency which might reach 65% and a wide variation range in γR1 generation,while the frequency of its control (callus not treated with γ rays) was 32%-38% in R1 generation.The variated characters included plant-height,ear-shape,shell-color,awnedness and grain.It proved that γR,is a favourable generation for selection of good individual plant.80% and more of variated characters tended to be stable in γR2 generation in the next year,and γR2 could be regarded as a better generation for selection of stable lines.High-yield strain '880114' and the mutants with specific characters,such as early ripeness,dwarfness,macrograin and macrospike,were selected from γR2 generation.Analysis of esterase isozyme indicated that the strains and the mutants all possess characteristic bands.