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采用室内筛选与田间防效相结合的方法,对哈茨木霉抑制黄瓜尖孢镰刀菌的拮抗机制进行了研究。对峙培养结果显示,木霉菌和病原菌间均形成了较明显的抑菌圈,对病原菌的抑菌率达66.7%~85.8%,其中菌株TG、TM对枯萎病菌抑制作用较强。木霉菌可有效提高根系对病原菌的抗性,黄瓜植株接种枯萎病菌后,根系细胞大量死亡,而先接种木霉菌再接种病原菌后则减小了对根系的伤害。田间防效试验结果表明,TG和TM孢子悬浮液浓度在108个/mL时防效最好,分别为54.9%和49.4%。接种木霉菌植株根系抗性基因的表达量均高于对照植株,呈双峰趋势。在第6天时抗性基因表达量最高,WRKY6、MYB、PR-1、PAL、GST和GLU的表达量分别为对照的5.15、5.22、6.07、6.00、3.16、和16.15倍。表明木霉菌通过激活与胁迫相关的基因表达提高了对病原菌的抗性。
The antagonistic mechanism of inhibition of Fusarium oxysporum by Trichoderma harzianum was studied by a combination of indoor screening and field control. The confrontation culture results showed that Trichoderma and pathogenic bacteria formed obvious inhibition zone, and the inhibitory rate to pathogenic bacteria was 66.7% ~ 85.8%. The strains TG and TM showed strong inhibitory effect on Fusarium oxysporum f. Trichoderma can effectively improve the root resistance to pathogenic bacteria, cucumber plants inoculated with Fusarium wilt, the root cells died in large numbers, but the first inoculation of Trichoderma re-inoculated with the pathogen to reduce the damage to the roots. The results of field control experiments showed that the control effect of TG and TM spore suspensions was the best at 108 / mL, 54.9% and 49.4% respectively. The expression level of root resistance genes of Trichoderma inoculation plants were higher than that of the control plants, showing a bimodal trend. The expression level of WRKY6, MYB, PR-1, PAL, GST and GLU were the highest at the 6th day, which were 5.15, 5.22, 6.07, 6.00, 3.16 and 16.15 times of the control, respectively. This indicated that Trichoderma increased the resistance to pathogenic bacteria by activating gene expression related to stress.