小麦叶内杀菌剂含量对条锈病组分的定量影响

QUANTITATIVE EFFECTS OF THE CONCENTRATIONS OF FUNGICIDES WITHIN WHEAT LEAVES ON DISEASE COMPONENTS OF YELLOW RUST

在田间,通过不同时期人工接种小麦条锈病菌(Puccinia striiformis West. f. sp. tritici Erikss)和施用杀菌剂三唑酮的组合,测定小麦叶内三唑酮及其代谢产物三唑醇含量对病害相对侵染几率(RIP)、潜育期(LP)、病斑扩展(LE)、产孢面积(SA)及传染期(IPe)等组分的定量影响。结果表明,施药后不同批次接种,在一定时间内,麦叶内药剂可降低病害相对侵染几率并延长其潜育期;接种后施药,在一个潜育期内,药剂可使病害潜育期提早。麦叶内药剂作用与品种慢锈性作用一致,即降低LE速率,缩小病斑面积和SA,缩短IPe。在试验基础上,动态量化麦叶内药剂含量对上述组分及其相对参数的影响。

Quantitative effects of the concentrations of fungicides triadimefon and triadi-menol within wheat leaves on relative infection probability (RIP), latent period (LP), lesion expansion (LE), sporulation area (SA) and infection period (IPe) of wheat yellow rust were measured by means of artificial inoculation of Puccinia striiformis West, f. sp. tritici Erikss and triadimefon application in the field during 1990-1992. The concentration of triadimefon and its metabolite triadimenol within wheat leaves at the moment of inoculation were also determined by gas chromatography technique. Results showed that fungicides within leaves reduced RIP and prolonged LP if triadimefon had been applied before inoculation. Fungicide within leaves could make the lesions appear ahead of time and shorten LP if inoculation was complete before triadimefon application during a latent period. No matter inoculation was before or after the application of triadimefon, the effects of fungicides within leaves on the disease components were the same as those of slow-rusting resistance of wheat cultivars, which prolong LP, reduce the rate of LE, lesion area and SA, and shorten IPe. The effects of triadimefon and triadimenol within leaves on the components and their relative coefficients were quantitat-ed.