化感杂交稻田间抑制稗草能力及其杂种优势表现

Inhibitory Effect on Barnyard Grass in Field and Its Heterosis Expression of Allelopathic Hybrid Rice

以4个化感稻品系与7个不育系所配的28个化感杂交稻组合为材料,以美国强化感稻PI312777为对照,研究了化感杂交稻田间抑制稗草的能力及其杂种优势表现。结果显示,化感杂交稻田间抑制稗草的主要因素是化感作用和竞争作用,其中化感作用对其整体抑草效应的影响较大;2012年早季的抑草效果优于2011年晚季,即环境条件影响了化感杂交稻抑草作用的发挥,其中竞争作用受环境影响较大;相关性分析表明,化感杂交稻的抑草作用对存活稗草地上部分生长量的影响主要是竞争作用的结果。从稗草株高及单株干物重来看,化感稻0210所配组合的抑草能力表现出很强的超父本和竞争优势,且田间表现稳定。基于封行前抑草率和灌浆期抑草率,有14个组合在早、晚季均表现出优于相应父本以及美国强化感稻PI312777的抑草效果,显示化感杂交稻在抗草育种中具有良好的利用前景。

Using 28 allelopathic hybrid rice combinations derived from four allelopathic rice lines and seven male sterile lines as the materials and PI312777, a strong allelopathic rice from the United States, as control, the inhibitory effect on barnyard grass [ Echinochloa crusgalli （ L. ） Beauv ] in the field and its heterosis expression of allelopathic hybrid rice were studied. The results showed that the inhibitory effect of allelopathic hybrid rice on barnyard grass in the field included allelopathy effect and competition effect but the allelopathy effect was bigger. The inhibitory effect of allelopathic hybrid rice on barnyard grass in early season of 2012 was better than that in late season of 2011, which means the inhibitory effect of allelopathic hybrid rice on barnyard grass was influenced by environmental conditions. The competition effect was varied more greatly with the environment. Through the correlation analysis, the competition effect was found to be the main factor affecting the above ground growth of barnyard grass. In regard to plant height and plant dry weight of barnyard grass, the hybrids of allelopathic rice 0210 showed strong heterosis over its male parent and strong standard heterosis in the field for both seasons of 2011 and 2012. Based on weeds suppression rate before crop closure and weeds suppression rate at grain filling stage, 14 allelopathic hybrid rice combinations showed stronger inhibitory effect on barnyard grass than the corresponding male parent and PI312777 in two seasons, indicating a promising prospect for the use of allelopathic hybrid rice in weeds-resistant breeding.