产酶溶杆菌OH11代谢产物HSAF对梨树腐烂病的防治效果

Control Effect of HSAF from Lysobacter enzymogenes OH11 on Pear Valsa Canker

HSAF(heat stable antifungal factor)是产酶溶杆菌Lysobacter enzymogenes OH11中分离鉴定的一种小分子广谱抗真菌和卵菌物质,为进一步明确HSAF防治梨树腐烂病的潜力,分别采用生长速率测定法、显微镜观察法和刮治涂抹法测定了HSAF对梨树腐烂病菌的室内毒力以及对梨树腐烂病的田间防治效果。结果表明,HSAF对梨树腐烂病菌有较强的生长抑制作用,EC50值为0.5μg/m L;HSAF可导致梨树腐烂病菌菌丝体出现扭曲、近顶端处分枝和顶端肿胀等畸形现象;40μg/m L HSAF凝胶剂对梨树腐烂病的涂治愈合率可达81.3%,与2.12%腐植酸铜水剂的涂治愈合率(85.3%)无显著差异;对于分枝裂口或冻伤处、向阴、主杆或中心枝上的病疤,经40μg/m L HSAF凝胶剂涂抹后的愈合率高于2.12%腐植酸铜水剂。对于剪锯口处和向阳或分枝上的梨树腐烂病病疤,经2.12%腐植酸铜水剂涂抹后的愈合率高于40μg/m L HSAF凝胶剂;两种药剂对不同位置病疤的涂治效果不同,可作互补使用。本研究结果为梨树腐烂病的田间防治提供了一种新的生防制剂,同时也可望为其他果树腐烂病害的防治提供生防药剂资源。

Control effects of HSAF （heat stable antifungal factor） from Lysobacter enzymogenes OH11 on pear valsa canker （Valsa pyri） were evaluated by mycelial morphology observation and HSAF gel smeared on canker scars under indoor and field conditions. Results showed that HSAF had strong inhibition on mycelial growth of V. pyri with the ECs0 value of 0.5 μg/mL. HSAF also resulted in abnormal mycelial morphology, such as curling, branching spots near the tip of mycelia and tip swollen. There were no significant difference between 40 μg/mL HSAF gel and 2.12% copper humic acid water agent treatments, with healing rate of canker scars of 81.3% and 85.3%, respectively. Moreover, 40 μg/mL HSAF gel showed better control effect than that of 2.12% copper humic acid water agent when smeared on canker scars that caused by cold injury or cleft, or canker scars lied in shady side, trtmk or center main trunk. However, the control effect of 2.12% copper humic acid water agent was better than that of 40 ~tg/mL HSAF gel when smeared on the other kinds of canker scars. This study provides a novel biological agent for the control of pear valsa canker.