感抗油菜近等基因系混播对根肿病发病率的影响

Effect of mixed-sowing of near-isogenic lines on the clubroot disease controlling efficiency in rapeseed

近年来,根肿病的迅速蔓延已对我国油菜生产造成严重威胁。课题组前期多年多点大田试验发现,感病、抗病品种混播可显著降低感病油菜品种根肿病发病率。为进一步探究感病、抗病品种播种间距对根肿病的防控效果,本试验采用穴盘栽培,设置感、抗根肿病油菜近等基因系不同播种间距(0、2、4、6 cm),出苗后7 d接种根肿菌,接种42 d后调查幼苗发病率、病情指数,并测定根系主要成分。结果表明:(1)与单播相比,感病、抗病品种同播时,抗病品种苗期发病率无明显变化,而感病品种苗期发病率显著下降,其发病率与感病、抗病品种播种间距密切相关,二者距离为0 cm时的发病率及病情指数均显著(P<0.05)低于其他处理;(2)与单播相比,感病、抗病品种同播时,抗病品种和感病品种根中可溶性糖及可溶性蛋白质含量均显著降低,酸不溶木质素含量在感病品种中显著增加,而在抗病品种中呈现先增加后降低的趋势;(3)发病率和病情指数均与根系可溶性糖和可溶性蛋白质含量显著正相关(P<0.01),发病率与可溶性糖和可溶性蛋白质含量的相关系数分别为0.797、0.403,病情指数与可溶性糖和可溶性蛋白质含量的相关系数分别为0.822、0.509。综上,油菜感、抗品种混播可以显著降低感病品种的根肿病发病率,且混播间距在0 cm时效果最好。该技术可以作为油菜根肿病防控的技术措施,在根肿病发病区域油菜生产上有着较好的应用前景。

The clubroot disease caused by Plasmodiophora brassicae has become a serious threat to rapeseed production in these recent years.In the previous multi-plot and multi-season field experiments,we found that planting of susceptible and resistant cultivars(near-isogenic lines)at different proportions could significantly suppress the incidence of the clubroot disease.In order to explore the preventive and control effect of mix-sowing of susceptible and resistant cultivars on clubroot disease,and identify the factors affecting mixed sowing.Pot experiments with different distance(0,2,4,and 6 cm)between the seeds of the resistant and susceptible cultivars were set by artificial inoculation at the 7 days after germination in this study.The disease incidence,disease index and the root biochemical components of rapeseed were measured after forty-two days.The results were as below:(1)the incidence of the resistant cultivar showed no significant change,while the disease incidence and disease index of the susceptible rapeseed cultivars decreased in the mixed-sowing treatment.Further,the disease incidence was significantly influenced by sowing distance of the two cultivars,which was significantly(P<0.05)lower than those of the other treatments when mixed-sowed at 0 cm.(2)compared to the single planting,the content of soluble sugar and soluble protein in roots of the mixed-sowing treatment were significantly(P<0.05)decreased for the two cultivars,and the content of acid-insoluble lignin was significantly increased in susceptible cultivar whereas decreased after increasing in resistant cultivar.(3)the results of correlation analysis showed that the content of soluble sugar and soluble protein were positively correlated with the disease incidence and disease index.The correlation coefficients between disease incidence and soluble sugar and soluble protein content were 0.797 and 0.403,respectively,meanwhile,the correlation coefficients between disease index and soluble sugar and soluble protein content were 0.822 and 0.509,respectively.In conclusion,the findings provided a new idea for prevention of clubroot disease in the field production in rapeseed.