2种雀稗属牧草种子休眠机理及其破除方法研究

Seed Dormancy Mechanism and Breaking Technique of Two Paspalum Species

以2种雀稗属牧草种子为材料,从种子的吸水性、浸提液活性的生物测定和GA3、ETH、IAA等外源激素浸泡处理等角度,研究2种雀稗属牧草种子休眠机理及破除方法。结果表明:1)2种雀稗属牧草种子生活力均达到92.2%以上,但发芽率较低。宽叶雀稗和巴哈雀稗的发芽率分别仅为59.3%和10.0%,都具有明显的休眠现象。2)2种雀稗属牧草种子的种皮均不限制种子吸水,但巴哈雀稗种子种皮对种子萌发有机械障碍。3)2种雀稗属牧草种子浸提液对白菜种子及自身萌发具有明显的抑制作用,说明2种雀稗属牧草种子内源抑制物含量较高。可知,宽叶雀稗种子休眠属于生理休眠,巴哈雀稗种子休眠属于综合休眠。4)GA_3、IAA、ETH、H_2SO_4及复合处理对宽叶雀稗种子萌发均有不同程度的抑制作用。GA_3、H_2SO_4及复合处理对巴哈雀稗种子萌发有促进作用。H_2SO_4处理5min巴哈雀稗种子效果最佳,可提高发芽率35.3%。

The seed dormancy mechanism and methods of breaking dormancy of two species of Paspal- urn were investigated by measuring seeds water absorption, bioassay of extracts and treatment of exterior hormones including GA3 ,ETH, IAA and so on.The results showed that： 1） The seed viability of two Paspalurn species was above 92%, but the germination rate was low. The germination rate of Paspalum wettsteinii was 59.3% ,and the germination rate of Paspalum notatum was only 10.0%.All of them had obvious dormancy. 2） The seed coat of two species of Paspalum did not restrict the water absorption of seed,but the seed coat of P.notatum had mechanical barrier to seed germination. 3） The seed extract of P.notatum had obvious inhibitory effect on the seeds and self-germination of Chinese cabbage,which indicated that the contents of endogenous inhibitors were higher in two species of Paspalum. It will be seen from this that, seed dormancy of P.notatum belongs to physiological dormancy,and seed dormancy of Paspalum notatum belongs to comprehensive dormancy. 4） GA3, IAA,ETH,H2SO4 and compound treatments had different inhibition effects on seed germination of P.wettsteinii.GA3, H2SO4 and compound treatments had a positive effect on seed germination of P.nota- turn.5 min H2SO4 had the best effect on seed germination,and the germination rate increased by 35.3%.