【摘要】 对B501在草莓根际的定植范围、群体数量的动态变化及对其他根际微生物种群与数量的影响进行了研究。结果表明,B501主要定殖于草莓根际与根表,B501的群体数量随草莓的生长呈动态变化。在根际,B501的数量水平以盛花期最高,在根表,数量水平呈渐增趋势,B501对草莓根际与根系可培养丝状真菌群体数量,对根系细菌总量的影响不显著;对根际细菌总量、根际与根系芽孢杆菌的数量有明显促进作用,连续两年的田间防效分别达到了93.9％和96.8％。更多还原

【Abstract】 Bacillus subtilis strain B501, isolated from strawberry rhizosphere, is an effective biocontrol agent for strawberry wilt. Colonization and population dynamics of Bacillus subtilis B501 in the rhizosphere and roots of strawberry were studied; the effects of B501 on other microbes were tested as well. The results indicated that the colonization zone of B501 is in the rhizosphere and rhizoplane. The population sizes of B501 were maintained above 10 cfu/g dry soil weight (DSW) in ectorhizosphere, 10 cfu/g fresh root weight (FRW) in rhizosphere and rhizoplane during the whole growing period (about 8 months) of strawberry. The period of highest population sizes of B501 was at flouring stage in rhizosphere and was at fruitful stage in rhizoplane. The populations of strain B501 at both stages were 9.26× 107 cfu/g DSW and 7.66 × 105 cfu/g FRW respectively. Compared with blank and methyl bromide treatment, the effects of B501 were not obvious on culturable filamentous fungi in rhizosphere and roots as well as bacteria in roots. The results also showed that B501 strain could promote the proliferation of bacteria in rhizosphere and bacillus in rhizosphere and roots. The promotional effect of B501 strain on actinomycetes was the same as methyl bromide treatment, which was much higher than blank. The field control efficiency for strawberry wilt was 93.9% in 1999 and 96.8% in 2000.更多还原