小麦抗麦茎蜂机制初步探讨

对青海、甘肃两地空心茎秆小麦抗麦茎蜂机制进行了初步研究。结果表明，断茎率与植株成熟时的株高、各节间长度、外径、干重呈正相关，与分蘖数，茎秆各节间实心负相关，抗虫小麦品系在麦茎蜂产卵期茎壁较厚，不利于麦茎蜂产卵；麦茎蜂幼虫取食时，茎秆内物质向其它部位运输，茎壁厚度下降至低于感虫品种，因而可能使幼虫所需营养物质的摄入量不足而使其生长发育受到影响。同时抗虫品系茎秆各部位养分较早向外运出，也可能对幼虫营养

Preliminary Study on Mechanism of Resistance to Wheat Stem Sawfly

The mechanism of resistance to the wheat stem sawfly(Cephus fumpennis Eversmann.)in hollow-stemmed wheat was studied based on the results offield experiments in Qinghai and Gansu province.Using cutrate of culm caused by the wheat stem sawfly as the criterion for resistance,the resistance to the wheat stem sawfly had significantly positive correlation with plant height,length of internodes,diameter of culm,dry weight of internodes respectively and had negative correlation significantly with number of tillers,so lidness ratio of culm when plant maturation.The dynamic growth of the culmindicated that the wheat resistant to the wheat stem sawfly had a thicker culm wall during the period offemale wheat stem sawfly laying eggs. But the culm wall became thiner than the susceptible cultivars while the larvae began to feed.In this case larvae were out offaviour with sufficient nutrient,and the growth and development was probably inhibited.Additionally,it was not good for larvae obtaining nutrient because the substance exported in the resistant was earlier than the susceptible.The mechanism of resistance to the wheat stem sawfly should be regarded as a result caused by synthetic factors during the period of plant growth and development.