化感稻新品系抑制稗草能力的田间表现

Inhibitory effect of new allelopathic rice strains on barnyard grass in the filed

为了比较22个化感稻新品系和美国强化感稻PI312777抑制稗草的能力,采用田间小区试验,对水稻封行前抑草率、竞争抑草率、灌浆期抑草率、伴生稗草平均株高和稗草单株干物重进行调查分析。结果显示:化感稻的抑草作用受环境条件影响,其中化感作用表现相对稳定,竞争作用随环境变化较大;化感稻的抑草作用主要表现在抑制稗草萌发和资源竞争力弱的稗草死亡,封行前抑草率是影响其抑草效果的主要因素。基于灌浆期抑草率,初步筛选到12份抑草特性强且田间表现相对稳定的化感稻新品系3、4、6、7、12、14、15、16、17、19、21、22,其中化感稻新品系15、16在2011年晚季和2012年早季均表现出较强的抑草特性,化感稻新品系6、15、19在2011晚季的抑草特性优于美国强化感稻PI312777,这些强化感稻新品系的筛选将有助于化感稻商业品种的选育及生产应用。

Inhibitory effect of 22 new allelopathic rice strains on barnyard grass 〔Echinochloa crusgalli（L.） Beauv 〕 was compared with PI312777, a strong allelopathic rice of the United States as control, by using field plot experiment. The inhibition rate before sealing line, inhibition rate of competition and inhibition rate of filling stage of allelopathic rices, and the average plant height and the dry weight per plant of associated barnyard grass were investigated in this paper. The results showed that the inhibitory effect of allelopathic rice on barnyard grass was influenced by environmental conditions, and the allelopathy effect was relatively stable, while the competition effect varied greatly with the environment. The allelopathic rices mainly inhibited weed germination and made weak resource competitive weed to death. The inhibitory rate before sealing line was the main factor affecting the total inhibitory effect of allelopathic rices on barnyard grass. Based on the inhibitory rate of filling stage, we preliminarily screened 12 new allelopathic rice strains with strong and relatively stable inhibitory effect on barnyard grass in the field, they were allelopathic rice strains 3, 4, 6, 7, 12, 14, 15, 16, 17, 19, 21 and 22, in which strains 15 and 16 showed strong inhibitory effect on barnyard grass in late season of 2011 and early season of 2012 and strains 6, 15, and 19 showed stronger inhibitory effect on barnyard grass than PI312777 in late season of 2011. The screening of these new allelopathic rice strains will help the breeding and production application of commercial allelopathic rice.