中文摘要：

为挖掘核桃内生菌的生物防治潜能。对核桃的内生菌和病原菌进行了分离，并通过平板对峙和发酵液抑菌试验，对其体外互作进行了研究。结果发现3株核桃内生细菌XHE7、XHE8和XHEl2对2种病原真菌HK2（Colletotrichium sp．）和HDl（Alternaria sp．）有拮抗作用，抑制率高达82％。其发酵液对HK2的抑制作用高达100％。对其中2株拮抗作用明显的细菌进行了生理生化和16SrDNA分子鉴定，初步确定XHE8和XHEl2皆为芽孢杆菌（Bacillus sp．）。

英文摘要：

In order to exploring the biocontrol talent of walnut endophytic bacteria, several endophytes and tWO pathogens in walnut were isolated, and the in vitro interactions between endophyte and pathogens were studied by using plate-confrontation and zymotic fluid inhibition assay.The results showed that three endophyt- ic strains XHE7 ,XHE8 and XHEI2 represented significant antagonism to both HK2（ CoUetotrichium sp. ） and HD1 （Alternaria sp. ）, and the highest inhibition rate reached 82.01%.Their zymotic fluid could suppress HK2 growth rate as high as 100%. Combined physiological and biochemical characters with 16S rDNA sequencing results,both strains XHE8 and XHE12 were identified as Bacillus sp..