麦穗形态学与抗吸浆虫的关系研究

文章系统观测了85个品种材料的小穗高度、宽度、密度,抽穗期麦芒与穗轴的夹角,抽穗期小穗与穗轴的夹角,第1对麦芒长,第2对麦芒长,护颖芒的长度,扬花盛期内外颖的开张角度和持续的时间,内外颖的长度差,内颖缘膜的宽度等。利用重量法测定了各品种的灌浆速度及扬花10天后千粒重与成熟期千粒重之比。结合生育期运用通径分析、主成分分析、多元回归等方法,找出了对抗性表现有显著作用的8个因子,以每穗虫量为依变量建立了估测品种抗虫程度的多元回归方程;从小麦吸浆虫的为害习性出发,提出了小麦对吸浆虫的抗性机制是多层次、综合性的论点,比较合理地解释了小麦品种对吸浆虫所表现的各种抗性类型。

STUDIES ON THE RELATIONSHIP BETWEEN THE MORPHOLOGY OF WHEAT EAR AND THE RESISTANCE TO WHEAT MIDGE

The present report deals with the relation of the morphologicalcharacters of wheat car and the resistance of wheat to wheat midgeSitodiplosis mosellana Gehin.Seventeen morphological factors of 85wheat varieties and lines representing the main features of ear andglumewere investigated in wheat field and laboratory.Path-,principalcomponent,and multi-regression analyses were used to determine thepossible factors contributed to wheat midge resistance;and an eight-factorial regression equation for evaluating the wheat midge resistancelevel of wheat variety with these morphological characters was devel-oped.The results showed that the midge resistance of wheat was multi-stratiform and synthetical,i.e.there were a series of preventive orsuppressive actions of wheat occurred in the ovipositing,hatching,invading or feeding processes,constituting the miscellaneous resist-ance to this insect pest.The nonpreference effcets,including the moreadvanced or postponed earing time than the occurrence peak of adults,the included angle between awn and axle of ear,and the shorterduration between heading to folwering,etc.,significantly reducedthe oviposition behavior of wheat midge;the mechanical effects,apeculiar kind of resistance to wheat midge,including the good fitnessof outside and inner glumes,the dense and strong margin hair ofinner glume,the larger width of spikelet and the included angle be-tween spikelet and axle of ear,prevented the hatching of eggs andinvading of larvae;the tolerance effects,including the longer milkystage and slower increase of kernel weight,reduced the yield loss ofwheat under the damage of S.mosellana.