^(60)Co-γ射线辐照高粱的生物学效应及适宜诱变剂量的研究

Study of Biological Effect and Appropriate Dosage of ^(60)Co-γ Ray in Sorghum Bicolor(L.) Moench

以60Co-γ射线辐照高粱材料,研究M1代种子萌发过程中植株形态及生理指标的影响,并对不同供试材料的适宜诱变剂量进行预测。用300、600、900、1200Gy剂量的60Co-γ射线辐照高粱654、ICSV111/1022和BTx623的干种子,调查了种子的发芽势、发芽率、发芽第12天幼苗生长量、活力指数以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性。结果表明:低剂量辐射(≤300Gy)对高粱种子的发芽势及发芽率有促进作用,剂量>300Gy时,逐渐转化为抑制作用;幼苗生长量、活力指数随着辐射剂量的增大而减小,与辐射剂量间存在显著的负相关关系;SOD、CAT、POD活性则与辐射剂量间存在显著的正相关关系,即随着辐射剂量的增大而增强。研究认为:M1代种子的发芽率、幼苗生长量、活力指数、SOD、CAT、POD活性的变化均可反映高粱材料的辐射诱变效应;不同材料耐受辐照的能力有所差异,ICSV111/1022>654>BTx623。3个高粱材料的适宜辐射诱变剂量差异很大,变幅在300~700Gy之间。

The dry seeds of three sorghum （Sorghum bicolor（L.） Moench） varieties, 654, ICSV111/1022 and BTx623, were irradiated by 60Co-γrays with 4 dosage levels. The morphologic and physiologic variations at germination and seedling stage were investigated and the appropriate dosage levels of 60Co-γray for different sorghum genotypes were estimated.The seed germination energy and germination rate were firstly promoted when the dosage level was lower than 300Gy,and eventually inhibited when the dosage level was increased. The seedling growth and vigor index were declined gradually with increasing dosage. The activities of protective enzymes SOD, CAT and POD were elevated gradually with increasing dosage. Significant negative correlation existed among seedling growth, vigor index and dosage, while the activity of protective enzymes had significant positive relationships with dosage. The results suggested that the interference effect could be evaluated by the parameters of germination rate, seedling growth, vigor index, SOD, CAT and POD activity in M1 plants. The irradiation endurance of 3 varieties was ICSV111/1022〉654〉BTx623. The suitable irradiation dosage for irradiation breeding of 3 sorghum varieties was determined within the range of 300~700Gy.