湖南长沙一季晚稻旱稻孢囊线虫发生动态及危害损失

目的 为了解旱稻孢囊线虫的田间发生动态,明确旱稻孢囊线虫的防治指标。方法 2016–2018年对长沙地区一季晚稻的旱稻孢囊线虫发生规律进行了定期定点调查,采用田间小区接种的方法测定了其不同群体密度下一季晚稻的损失,建立了旱稻孢囊线虫群体密度与产量损失的回归方程。结果 旱稻孢囊线虫发生动态调查结果表明,孢囊高峰期主要出现在水稻分蘖期末、孕穗期和黄熟期,推测旱稻孢囊线虫在长沙地区一季晚稻每年发生3代。小区接种试验测产结果表明,旱稻孢囊线虫对水稻株高、有效穗数、实粒重、结实率等农艺性状产生不利影响;每1mL土壤接种卵量≥4个,旱稻孢囊线虫危害较为严重,被害株实粒重损失在19.4%以上,应采取相应的防治措施。结论 我们分析了旱稻孢囊线虫发生世代数的影响因素和防治指标。研究结果可为指导长沙地区旱稻孢囊线虫防治提供理论依据。

Population Dynamics and Yield Loss Evaluation of Heterodera elachista in Single-cropping Late Rice in Changsha,China

【Objective】 It is very important to clarify population dynamics and the economic threshold of Heterodera elachista 【Methods】Soil and root samples were periodically collected in a single-cropping late rice field in Changsha, Hunan Province from 2016 to 2018. Effects of population density of H. elachista on agronomic traits and yield loss of rice were determined by artificial inoculation. 【Result】The population density of cysts mainly showed three obvious peaks, occurring at the late tillering stage, booting stage and yellow maturity stage, respectively. It was deduced that H. elachista had three generations in single-cropping late rice in Changsha. The plot test indicated that H. elachista had adverse effects on agronomic traits of rice such as plant height, effective panicle number, solid grain weight and seed setting rate. When the inoculation amount of H. elachista was ≥4 eggs/mL, the damages of H. elachista were relatively serious and the weight loss of the damaged plant was more than 19.4%, so that corresponding control measures should be recommended. 【Conclusion】We analyzed the influential factors behind generation number and control index. It will lay a solid basis for H. elachista control in Changsha.