温度和湿度及水稻不同生育期对水稻干尖线虫垂直迁移的影响

Effects of Temperature,Humidity and Different Growth Stages of Rice on the Vertical Migration of Aphelenchoides besseyi

研究了不同温度和湿度对水稻干尖线虫垂直迁移的影响以及线虫在水稻不同生育期生长繁殖和垂直分布状况。结果表明,线虫迁移的最适温度为25～30℃。在温度适宜的条件下,相对湿度越高,线虫迁移率越高。温室接种实验表明水稻拔节期线虫主要分布在接种点周围及水稻上部,且虫量递减明显,20 d后线虫虫量仅为接种5 d时的50%。孕穗期线虫主要分布在水稻的幼穗中,并且大量繁殖,20 d后线虫虫量为接种5 d时虫量的3倍。

The vertical migration of Aphelenchoides besseyi under different temperature and humidity conditions and in different rice growth stages were investigated. It was found that the optimum temperature for development and reproduction of A. besseyi was 25 ℃ to 30℃. At the same temperature, the rate of vertical migration increased with the rising relative humidity. Artificial inoculation tests showed that at the rice elongation stage, nematodes mainly survived on the upper and middle parts of rice stem, and the number decreased by 50G at 20 days after inoculation compared with that at 5 days after inoculation. Whereas at the rice booting stage, nematodes gathered in young panicle and reproduced quickly, and twenty days after inoculation the number was 3 times as many as that at 5 days after inoculation.