低温层积对纳罗克非洲狗尾草种子活力及其幼苗生长的影响

The Effect of Cold Stratification on Seed Vigor and Seedling Growth of Setaria sphacelata cv. Narok

纳罗克非洲狗尾草(Setaria sphacelata cv.Narok)是热带、亚热带地区优良的牧草兼地被植物,但其种子休眠程度深,严重制约了该植物的推广利用。为破除种子休眠,对1年龄纳罗克非洲狗尾草生产的种子进行了低温层积处理,结果表明:低温层积15 d种子休眠已基本解除,层积30 d休眠已完全解除,此时种子的发芽率达到75%,是对照的2.08倍,已接近种子本身的生活力水平(78.3%),种子的发芽势、发芽指数、活力指数、幼苗高和胚根长则分别达到74%、23.15、0.0263、5.06 cm和1.20 cm,分别是对照的2.55、2.35、2.27、1.38和1.36倍,差异达到极显著水平(p<0.01)。

Setaria sphacelata cv. Narok is one of excellent tropical and subtropical grass forages. However the deep seeds dormancy restricts the popularization and utilization of this forage. Cold stratification was applied to break dormancy of？Narok seeds from one year old plants. The results？showed that 15-30 days of cold stratification could break Narok seed dormancy. 30days later, seeds dormancy has been completely removed, and the germination rate reached 75% closing to the seeds potential life force level （78.3%）., increased by 2.08 times compared with the control. The germination force, germination index, vigor index, seedling height and radical length were 74%, 23.15, 0.0263, 5.06 cm, 1.20cm respectively, and increased by 2.55 times, 2.35 times, 2.27 times, 1.38 times, and 1.36 times compared with the control respectively, and reached significant difference at 0.01 level.