Abstract:

Four strains of actinomyces were used to investigate their abilities in overcoming continuous cropping obstacles and effects on strawberry growth through liquid culture and greenhouse experiments. It was shown that the degradation rates of para-hydroxybenzoic acid in liquid culture by the 4 strains of actinomyces were 97.6%～98.7% after 7 days. Similarly, the para-hydroxybenzoic acid in the strawberry planting soil could be degraded efficiently by these 4 actimonyces in greenhouse experiment. Comparing to the CK treatment, contents of para-hydroxybenzoic acid decreased significantly in the soil around the root when treated by 251, 252 and 40 actinomyces during the planting season was ending. The total weight of strawberry root and new root increased 28.5%～50.4% and 25.7%～802%, respectively, after 4 actinomyces were used, indicating that they could promote the root growth and plant tiller of strawberry. The actinomyces could also decrease mortality and disease rates with relative effects of 51.9%～56.3%. But no significant effects were found on the total weight of strawberry plant, its leaf areas and PPO activity of leaf blades.

Key words: actinomyces, strawberry, autotoxins, microbial degradation, allelopathy

摘要：

通过液体培养及温室连作草莓土壤修复试验,从自毒物质降解角度研究了4株放线菌对草莓连作障碍的修复作用及对草莓生长的影响。结果表明:在液体培养条件下,7 d后4株供试放线菌对对羟基苯甲酸的降解率达到97.6%～98.7%。同样,在温室连作条件下,4种供试放线菌制剂对草莓根区土壤中的对羟基苯甲酸有明显的降解作用。与对照相比,在草莓种植结束时,251、252、40号菌剂处理的草莓根区土壤中对羟基苯甲酸含量显著下降。供试放线菌接种处理后,草莓根系总重量及新根较对照分别增加28.5%～50.4%及25.7%～80.2%,表明其对草莓根系生长和新根形成有明显促进作用。菌剂还能有效降低草莓植株死亡率和发病率,相对防效达到51.9%～56.3%。但他们对连作温室草莓植株总重量、叶面积及叶片PPO活性影响不明显。

关键词: 放线菌;草莓;自毒物质;微生物降解;化感作用