供钼水平对4株柱花草根瘤菌生长的影响

摘要

为研究不同钼水平对柱花草根瘤菌生长的影响,将4株柱花草根瘤菌接种于不同钼浓度的YMA固体和液体培养基上,通过对根瘤菌生长定性和定量分析,确定不同钼处理对根瘤菌的影响.结果表明:缺钼处理对4株根瘤菌的生长均无显著影响;在钼处理下,4个菌株对钼的耐受能力存在差异,菌株PN13-3的耐钼能力最强,可以耐受的钼浓度为3000 mg/L,LZ3-2和YM11-1次之,RJS9-2最差,可以耐受的钼浓度为1500 mg/L;高浓度钼处理使菌株PN13-3、YM11-1(≥2000 mg/L)和LZ3-2(≥2500 mg/L)的对数生长期延长,稳定生长期缩短,使菌株RJS9-2(≥500 mg/L)迟缓期延长,对数生长期缩短.%The effects of different molybden um ( Mo) levels on the growth of four rhizobial strains isolated from Stylosanthes were investigated using the solid yeast mannitol agar (YMA) and liquid YMA medium. The growth of rhizobial strains was evaluated by qualitative and quantitative analysis under different Mo treatments. The results showed that no significant difference was observed among the four tested rhizobial strains without Mo addition. Rhizobial strains exhibited variations in Mo tolerance. The rhizobial strain PN13-3 showed higher Mo tolerance than the other three strains, as reflected by better growth performance under 3000 mg/L Mo treatment, whereas the growth of RJS9-2 was significantly inhibited by 1500 mg/L Mo treatment. Furthermore, PN13-3 and YM11-1 with Mo supply above 2000 mg/L, and LZ3-2 at a Mo concentration greater than 2500 mg/L exhibited increased the logarithmic growth phase and decreased the stationary phase, while 500 mg/L Mo treatment increased the lag phase and decreased the logarithmic growth phase of RJS9-2.