【摘要】 本文研究了野生稻暗色有隔内生真菌稻镰状瓶霉与水稻的共生关系,通过根部接种DsRED荧光标记菌株,观察稻镰状瓶霉在水稻根系内的定殖,并对其抗白叶枯病特性进行调查,结果发现:经叶部接种白叶枯病菌后,对照组发病严重,病级集中在7级和9级,分别占比43.33%和34.67%,病情指数为79.26;相比之下,接种了稻镰状瓶霉的水稻植株发病较轻,叶片病斑面积小,并伴随零星黑色过敏性坏死斑出现,未发病植株占8%,72%的植株病级为1级,病情指数仅为15.26。稻镰状瓶霉对水稻白叶枯病的防治效果达到80.75%。稻镰状瓶霉的定殖能够引起叶片中超氧化物歧化酶、过氧化氢酶和过氧化物酶活性极显著提高,分别是对照组的5.26、12.08和10.53倍;诱导PR1a和PR1b显著上调表达8.71和3.37倍,AOS、OsSAUR2和EL5基因显著下调表达0.28、0.57和0.65倍。利用野生稻内生真菌防控水稻白叶枯病,在国内外尚属首次,可为水稻白叶枯病的生物防治提供新途径。更多还原

【Abstract】 The symbiosis of dark septate endophyte Falciphora oryzae isolated from Oryza granulata and rice was reestablished. The colonization pattern was monitored via inoculation of DsRED fluorescent protein-expressing F. oryzae on rice roots. To investigate the resistance induced by F. oryzae, the leaves of control and F. oryzae-colonized plants were inoculated with pathogenic Xanthomonas oryzae pv. oryzae(Xoo).The results showed that foliar infection of control plants with Xoo resulted in serious blight lesions. The disease ranged at rank 7 and 9 which accounted for 43.33% and 34.67%, respectively. The disease index was up to 79.26. Upon infestation with F. oryzae, leaves were protected from Xoo infection as evidenced by reductions in lesion size and severity, only with a few hypersensitive spots. It was clear that 8% of F. oryzaecolonized plants was not infected by Xoo. A large proportion of F. oryzae-infected plants ranged at rank 1,accounting for 72%, while its disease index was reduced to 15.26. The biocontrol efficiency of F. oryzae against Xoo was up to 80.75%. F. oryzae-inoculated roots showed 5.26-fold greater superoxide dismutase(SOD)activity in comparison with controls. Meanwhile, catalase(CAT) and peroxidase(POD) activities were elevated by 12.08-and 10.53-fold after infestation with F. oryzae, respectively. Due to the colonization of F. oryzae, the expressions of PR1 a and PR1 b were significantly up-regulated by 8.71-and 3.37-fold, while the expressions of AOS, OsSAUR2 and EL5 were significantly down-regulated by 0.28-, 0.57-and 0.65-fold, respectively. It was first reported to apply endophytic fungi isolated from wild rice against rice bacterial blight. It provided a novel measure for managing plant disease.更多还原