水稻叶色突变对虫害发生影响的研究初报

为明确叶色标记水稻在生产中可能引起的虫害发生变化,本试验在使用和不使用农药防治的情况下,以常规品种嘉禾218为对照,对龙特甫B及其2个叶色突变系黄玉B、翠玉B田间虫害情况进行了调查.龙特甫B为正常绿叶籼稻品种,黄玉B、翠玉B全生育期分别表现黄色和翠绿色,在苗期、分蘖期和抽穗期,黄玉B较龙特甫B的叶绿素含量分别下降58.O%,48.4%和40.8%,翠玉B则分别下降39.5%,36.0%和29.5%.结果表明,秧田期2个叶色突变体上的稻蓟马虫量显著高于其亲本龙特甫B;本田期灰飞虱和褐飞虱的虫口数在不同材料间或差异不显著,或存在显著差异,但没有一定的规律性.但是,2个突变体受稻纵卷叶螟的危害显著轻于龙特甫B,表现为盛发期突变体受稻纵卷叶螟危害产生的虫苞数显著少于龙特甫B,而龙特甫B与嘉禾218之间没有显著差异;相反,2个突变体植株上白背飞虱的虫量显著大于龙特甫B,龙特甫B也显著大于嘉禾218.根据植株的农艺性状和叶绿素含量,以及虫害发生动态变化,笔者推测,造成叶色标记水稻稻纵卷叶螟危害变轻的原因可能与植株叶绿素含量下降,影响幼虫生长发育有关,但引起白背飞虱虫口增加的原因尚需进一步研究.本试验为首次对叶色标记水稻虫害发生情况进行研究,所得结果不但对完善叶色标记水稻生产体系具有指导意义,同时对研究害虫与水稻叶色之间的关系也具有理论价值.

A PRELIMINARY STUDY ON THE EFFECT OF LEAF COLOR MUTANTS ON INSECT PEST OCCURRENCE IN RICE

To reveal any potential change of insect pest infestation in which rice plants with marked leaf color are cultivated in paddy fields and the occurrence of several insect pests were investigated in plots of Longtefu B and its two leaf color mutant lines Huangyu B and Cuiyu B,with and without pesticide control and conventional variety Jiahe 218 is used as a control. Longtefu B is normal green leave indica variety,Huangyu B and Cuiyu B have yellow and vivid green leaves respectively.The total chlorophyll(Chl)content of Huangyu B was reduced by 58.0%,48.4%and 40.8%in leaves at seedling,tillering and heading stage,respectively,compared with 1.ongtefu B,while that of Cuiyu B was reduced by 39.5%,36.0%and 29.5%, respectively.Field observations indicated that the number of larvae were either not significantly different or significantly but not consistently different between Longtefu B and its two mutants for small brown planthopper(Laodelphax striatellus)and brown plant hopper(Nilaparvatat talugens).However,the damage caused by rice leaffolders(Chaphalocrocis medina)was less severe in the two mutant lines than in Longtefu B with less folded leaves were observed in the two mutant lines than in longtefu B during the peak occurrence time,while there was no difference between Longtefu B and Jiahe 218.On the opposite,more larvae of white back plant hopper were observed in the two mutant lines than Longtefu B(with 177.3%and 228.7% increase,respectively),and Longtefu B had been infected with more larvae than Jiahe 218.Based OR agronomic performance, Chl content,and the dynamics of pest occurrence,it is assumed that the reduction of Chl content migIlt be the causative factor of reduced damage by leaf folders,while it is yet unclear why the white back hopper surged in the two mutant lines,which needs further studies.This is the first study to the authors'knowledge on the occurrence of insect pests in rice with colored leaves,hence the results can be of guidance for improving the special rice production system,and it is also of importance for understanding the relationship between leaf color and insect pest occurrence.