出芽短梗霉菌菌株PA-2的除草活性及对作物的安全性

从青海省平安县发病杨树叶片上分离得到菌株 PA-2，其发酵滤液对多种阔叶杂草表现出较好的除草活性。对该菌株的培养特征和16S rDNA基因序列分析后，确定其为短梗霉属出芽短梗霉菌Aureobasidium pullulans。盆栽试验表明，其发酵滤液对供试阔叶杂草猪殃殃、藜、冬葵、酸模叶蓼及禾本科野燕麦的鲜重防效分别达到87.25%、78.46%、82.25%、62.11%、80.27%。作物安全性试验结果表明，其发酵滤液对小麦、蚕豆、青稞很安全，对油菜、豌豆有轻微影响。综上所述，菌株 PA-2具有作为微生物除草剂的开发潜力。

Herbicidal Activity of Aureobasidium pullulans PA-2 on Weeds and Its Safety on Crops

Strain PA-2 was isolated from diseased poplar leaves in Ping’an, Qinghai Province, the metabolites of the strain showed high herbicidal activity to target weeds. According to its culture characters and 16S rDNA sequence analysis, the strain was identified as Aureobasidium pullulans. The objectives were to determine mortality and fresh weight reductions of various weeds and to evaluate the host range of the fungus as influenced by the fermentation filtrate. The fresh weight reductions of A. pullulans to Galium aparine L. var. tenerum (Gren. et Godr.) Reichb., Chenopodium album L., Malva crispa L., Polygonum lapathifolium L., Avena fatua L. for weeds seedlings in the pot tests were 87.25%, 78.46%, 82.25%, 62.11%, 80.27%respectively. Responses of inoculated weeds to A. pullulans ranged from light symptoms to 100%mortality. G. aparine L. var. tenerum (Gren. et Godr.) Reichb. and M. crispa L. exhibited significant reductions in fresh weight. No significant fresh weight reductions were observed for Triticum aestivum L., Vicia faba L., Hordeum vulgare L. plants compared to the control plants. Brassica napus L. and Pisum sativum L. exhibited light spots on A. pullulans inoculated leaves with no significant reductions in fresh weight. These results indicated that A. pullulans could be a potential microbial herbicide for control of target weeds in crops.