禾谷孢囊线虫初始密度对其繁殖及小麦生长和产量的影响

为明确土壤中禾谷孢囊线虫(Heterodera avenae)初始密度(Pi)与小麦生长和产量的关系,在2011-2013年的两个冬小麦生育周期里,通过网室盆栽试验,分析了土壤禾谷孢囊线虫初始密度对其繁殖及小麦生长和产量的影响。结果表明,禾谷孢囊线虫的繁殖系数(Rf)随Pi的增加而减少,当Pi为0.5个卵·mL-1土时,Rf达到8.7;当Pi为64个卵·mL-1土时,Rf仅为2.8。小麦株高、茎叶干重、根干重及产量均与Pi呈显著负相关。当Pi≥8个卵·mL-1土时,小麦植株生长受到抑制,产量显著下降,因此田间禾谷孢囊线虫的初始密度高于该值时,应当采取有效措施进行防治。

Effects of Initial Population Density of Heterodera avenae on Nematode Reproduction and Wheat Growth and Yield

Cyst nematode Heterodera avenae is an important parasitic nematode on cereal crops.Clarifying the relationship between its initial population density (P_i) and wheat growth is critical to designing the integrated strategies for its control.During two growth seasons of winter wheat in year 2011-2013,the effects of initial population density of H.avenae on nematode reproduction and growth of wheat were evaluated in pot experiments under nature condition.The results showed that the reproduction factor (R_f) of H.avenae was decreased with the increasing density of H.avenae.The reproduction factor was 8.7 when P_i was 0.5 egg·mL^-1 soil,while R_f was 2.8 when P_i was 64 eggs·mL^-1soil.The plant height,aerial shoot dry weight,root dry weight and grain yield were also decreased,which showed a negative relationship P_i.The wheat growth and grain yield decreased significantly when P_i was higher than 8 eggs·mL^-1soil.Therefore,control measures should be carried out in wheat field when nematode density is higher than this economic limit value.