60Coγ辐射对木槿种子发芽及幼苗生长的影响

以60Coγ为辐射源,采用不同剂量率（50～500 Gy/h）辐照木槿休眠种子,对辐照后种子进行播种观察。结果表明：辐照剂量低于200 Gy时促进种子发芽,低于100 Gy时能提高幼苗成活率;辐照剂量大于200 Gy时抑制发芽,并导致真叶和侧根难以形成,直至幼苗死亡。剂量率对辐照效果有一定的影响。得出以提高苗木成活率为目的进行辐照时的剂量以50～100 Gy为宜,以促进变异为目的进行辐照时剂量以100～200 Gy为宜。

Effects of 60Co γ- Rays Irradiation on Germination and Seedling Growth of Hibiscus syriacus

The seeds of Hibiscus syriacus were irradiated by 60Coγ-rays at dose rate of 50～500 Gy/h for 0.5 and 1h, the seed germination rate and the seedling characters were surveyed. The results indicated that the seed germination was promoted when the absorbed dose was below 200Gy, and the seedling survival rate was increased when the dose was below 100 Gy. The germination was inhibited, leaves and secondary roots were difficult to form, and the seedlings blasting occurred when dose was over 200 Gy. The dose rate affects the irradiation results. Absorbed doses of 50～100 Gy were suggested for increasing seedling growth rate and 100～200Gy were recommend for mutagenesis.