快中子辐照紫花苜蓿的生物学效应与RAPD分析

BIOLOGICAL EFFECTS AND RAPD ANALYSIS OF ALFALFA (medicago sativa L.) IRRADIATED BY FAST NEUTRONS

采用直线加速器产生3.60×1011、7.10×1011和3.54×1012/cm2 3种辐照注量的快中子处理肇东苜蓿干种子,对其进行种子发芽试验、幼苗生长和RAPD分子标记分析。研究表明,经3种注量快中子处理后,肇东苜蓿种子发芽势和发芽率显著高于对照;幼苗的苗高和根长小于对照,随着快中子处理注量的增加,幼苗苗高降低和根长减少的幅度越大;当快中子辐照注量达到3.54×1012/cm2时,幼苗根长相比对照降低了81.63%,没有生长出真叶,只有子叶。RAPD试验共使用36种引物,结果显示,辐照注量为3.60×1011、7.10×1011和3.54×1012/cm2的快中子处理紫花苜蓿M1代的RAPD多态性频率分别为7.25%、6.52%和5.80%,3.60×1011/cm2处理辐照注量的RAPD多态性频率最高。在本研究的辐照注量范围内,3.60×1011/cm2是利用快中子诱变紫花苜蓿的适宜辐照注量。

Dry seeds of alfalfa variety Zhaodong were irradiated by fast neutrons generated by linear accelerator with three fluences,3.60×1011,7.10×1011 and 3.54×1012/cm2 respectively.Seed germination,growth,and RAPD analysis on the mutation were reported in this study.The results showed that germination vigor and germination rate of irradiated seeds were higher than those of control,but seedling height and root length were reduced with the increase of fluences.When the dosages reached 3.54×1012/cm2,seedling root length decreased by 81.63% compared with the control,but the seedlings didn＇t grow any true leaves except for cotyledon.36 primers were used in RAPD analysis,and the results showed that the RAPD polymorphic loci rate was 7.25%,6.52% and 5.80% among the 3.60×1011/cm2,7.10×1011/cm2 and 3.54×1012/cm2 treated M1 plants.RAPD polymorphic loci rate in the 3.60×1011/cm2 treated plants was the highest among three treatment.It is concluded that 3.60×1011/cm2 could be on optimum fluences for alfafa mutation by fast neutrons.