镧的植物防病效果及其生物学效应

Control Effect of Lanthanum Against Plant Disease

通过灭菌土接种Rhizoctonia solani以及混合接菌Rhizoctonia solani和Fusarium solani进行盆栽试验,分别研究了镧浸种处理对高羊茅及板蓝根出苗、生长发育的影响。结果表明,镧浸种能明显地减少病原菌的侵染,对由其所造成的种腐、芽腐及根腐等有显著的防治效果,提高了板蓝根和高羊茅种子的出苗率。同时,镧浸种在适当的浓度范围内,还能显著地促进植物的生长发育,生物量明显增加。利用盆栽水稻试验研究了稀土镧对水稻纹枯菌(Rhizoctonia solani)的毒力,测定结果表明,镧喷施于水稻植株上对水稻纹枯病有明显的防治效果,且在活体条件下,喷施镧后1和7 d对水稻纹枯菌(Rhizoctonia solani)的有效中浓度分别为128.7和128.1 mg.L-1,均明显低于离体条件下的有效中浓度(171.9 mg.L-1)。

Effect of La on emergence, growth and development of Isatis indigotica Fort. and Festuca arundinacea seedlings was researched by pot experiments of inoculating Rhizoctonia solani and the mixture of Rhizoctonia solani and Fusarium solani in disinfected soil after the seeds were soaked in the solution with different concentrations of La^3＋ . The results indicate that infection rate is decreased and there are significant disease controlling effects on seed rot, bud rot and root rot caused by pathogenic fungi when the seeds are soaked by La^3＋ . Thus, the rates of emergence of Isatis indigotica Fort. and turfgrass Festuca arundinacea are increased. When La^3＋ concentration is in a proper range, the growth and development of plant seedlings are promoted. Spraying La in rice plants shows a significant controlling effect on Rhizoctonia solani. Furthermore, the EC50 of La^3＋ performed at 1 and 7 d after spraying La in rice plants are 128.7 and 128.1 mg·L^-1 respectively. The ECho of La^3＋ performs in vivo （in rice plant） is lower than that in vitro （171.9 mg·L^-1）.