^(60)Co-γ射线辐照处理对杉木种子萌发及幼苗生长的影响

Effects of ^(60)Co-γ Radiation on Seed Germination and Seedling Growth of Cunninghamia lanceolata

为了探讨^(60)Co-γ辐射剂量对杉木种子萌发及幼苗生长的影响,本研究以杉木第3代种子园收集的种子为供试材料,研究了不同剂量的γ射线辐照处理对杉木种子发芽率、发芽时间、出苗率以及诱变苗早期生长的影响。结果表明:20 Gy辐照明显促进发芽,随着剂量的增加发芽率逐渐降低,80 Gy是致死剂量;辐照剂量20~60 Gy之间时,随着剂量的增加发芽时间会逐渐延长,出苗率会逐渐降低;γ射线辐照处理获得的诱变苗株高、地径和分枝数同样受剂量效应的影响,随着辐照剂量的增加,表现在植株矮化,地径变细,分枝数先升高后降低,尤其是40 Gy的辐照剂量能够显著促进分枝。根据辐照剂量与发芽率、出苗率可以初步确定,γ射线辐射杉木种子的半致死剂量在40~60 Gy之间。

In order to investigate the effects of different doses of60Co-γ radiation on seed germination andseedling growth of Cunninghamia lanceolata, the seeds collected from the third generation Cunninghamia lanceolata seed orchard were taken as materials to test the effects of different doses of gamma irradiationtreatments on the seed germination rate, germination time, seedling emergence rate and the mutagenic seedlinggrowth of Cunninghamia lanceolata. The results showed that： 20 Gy radiation obviously accelerated thegermination but the germination rate gradually decreased with the increase of the dose put into application and80 Gy was a lethal dose; with the dose increase, the germination time gradually extended while the seedlingemergence rate gradually decreased when the irradiation dose was between 20 Gy and 60 Gy. Different gammairradiation doses also had an effect on the height, ground diameter and branch number of the mutated plants,with the increase of irradiation dose, the plants tended to be dwarfed and the ground diameter decreased, whilethe number of branches first increased and then decreased; in particular, the 40 Gy irradiation dose couldsignificantly accelerate branching. It can be preliminarily ascertained that, according to the irradiation doses,the germination rate and the seedling emergence rate, the half lethal dose of gamma-ray radiation on Cunninghamia lanceolata seeds is between 40 Gy and 60 Gy.