春小麦品种对麦秆蝇抗性机制的研究

本文系1957—1979年间,根据多次田间调查春小麦品种对麦秆蝇抗性机制研究的结果。麦秆蝇有趋向遮荫较差麦田的习性,卵散产,主要产在叶片正面近基部处。研究结果表明,春小麦品种对麦秆蝇的抗性,主要是由此虫产卵对不同品种的选择性决定的。影响产卵选择性的特性已证明有生育期、叶面茸毛性、叶片宽度及叶片与茎秆间交角。抽穗愈早、叶面茸毛密而长、叶片狭或叶片与茎秆间交角大,则着卵较少。统计分析这些差异都是显著的。此外,有一年的田间调查表明叶色深的品种着卵较少,叶色深浅与着卵量有显著的负相关。但这需要进一步验证。还有,品种生育期的长短与幼虫入茎成活率,已证明有显著的正相关,因此品种生育期也起一定的抗生作用。

STUDIES ON THE MECHANISM OF RESISTANCE OF SPRING WHEAT VARIETIES TO THE WHEAT STEM MAGGOT MEROMYZA SALTATRIX Linnaeus

Since 1957,several field tests were conducted in successive years in Western Inner Mongolia to analyse the mechanism of resistance of spring wheat varieties to the wheat stem maggot,Meromyza saltatrix Linnaeus.The flies prefer wheat fields with less shading and lay eggs singly chiefly on the lower part of the upper surface of wheat leaves.In general,varieties receiving more eggs developed higher percentages of injured stems.Repeated field survey showed that the amount of oviposition-varies obviously with wheat varieties,indicating that nonpreference is the chief cause of varietal resistance.Analysis of accumulated data verified that the density of eggs is related with the length of growing period,leaf pubescence,width of leaf,the angle between leaf and stem during ovipositional period and probably the leaf color.The earlier the appearance of heading stage,the higher the density and length of leaf hairs,the narrower the leaves or the wider the angle between leaf and stem,the lesser the number of eggs laid.Statistical analyses proved that all such differences are significant.Besides,a single year field survey of 56 varieties indicated that the darker the leaf color the lesser the amount of oviposition,and a negative correlation was recorded.However,this needs to be verified by further observations.In addition,analysis of the ratio between the percentage of injured stems and that of oviposited tillers of various varieties in different growth stages during oviposition period showed that the growth stage also affecting the percentage of larval survival.According to observations on labelled oviposited stems of the same variety but in different growth stages during oviposition period,bearing one egg each,it has been recorded a positive correlation between the growth stage and larval mortality.Thereforc,the growth stage of wheat varieties during ovi-position period is proven to exhibit also some antibiotic action.