粳型杂交稻榆杂29穗颈稻瘟与肥力、密度和基本苗的相关性

Correlation between the panicle rice blast disease of Yuza 29 dian-type hybrid rice and the fertilization, planting density as well as basic seedlings

合理栽培是防治稻瘟病的重要措施。本研究以单产创世界纪录的高原杂交粳稻榆杂29为对象,进行了3因素(肥力、密度和基本苗数)5水平栽培试验,共12个处理,36个小区。分析了榆杂29穗颈稻瘟发病程度与肥力水平、栽插密度和基本苗数的关系。结果显示个别处理(处理水平12),重复(8,16,36)间穗颈稻瘟病情指数DSI(disease severity index)(3.8,16.7,4.9)相差2-3倍,揭示存在穗颈稻瘟发病中心。统计分析表明榆杂29穗颈稻瘟病情指数(Y)与所试验的肥力水平相关性不显著;与栽插密度(X1)和基本苗数(X2)显著正相关,回归方程Y=1.023357+0.514596 X1 X2。

Rice blast (Magnaporthe grisea) is a destructive disease of rice production worldwide. One of the major methods to control it is to exploit cultivation management, which has already been extended by Chinese plant pathologists in recent years. Here we report an experiment demonstrated that the correlation between the panicle blast disease severity index (DSI) of Yuza 29, a Dian-type japonica hybrid rice ever with a yield record 16.7t/hm2 in Yunnan Plateau, and the Nitrogen fertilization, planting density and the seedlings per hill. Five levels for each factor and 12 treatments inclusion of 36 plots in all were evaluated in field trials. Results implicated that there were several disease initial centers of panicle blast as big variance of DSI (such as DSI 3.8 in plot 8 against DSI 16.7 in plot 16) could be observed among repeats of a treatment (such as treatment 12) though most of the repeats were coincident in terms of DSI in a treatment. Results also showed that the miniclimate of the rice field has an effect on the incidence of panicle blast disease of Yuza 29. The Yuza 29 DSI (Y) was significantly and positively correlated to the planting density (X1) and seedlings per hill (X2) , the regression equation is Y = 1.023357 + 0.514596X1X2 but no noticeable correlation to the Nitrogen fertilization, which could be helpful for its cultivation management.