Abstract:

The effects of Monopotassium Phosphate, Fulvic Acid and Rare Earth Nitrate on the activity of alfalfa rhizobium were investigated using single factor and orthogonal experiment designs with Alfalfa rhizobium strain ACCC17631 and ACCC17676 as experimental materials in order to screen the optimum combination of medium. The results showed that Monopotassium Phosphate had significant influence on the activity of strain ACCC17631(P<0.01),the optimum concentration was 300 mg·L^-1, and no significant influence on the activity of strain ACCC17676. Fulvic Acid had highly significant influence on the activity of both test strains(P<0.01), the optimum concentration was 0.03% for strain ACCC17631 and 0.02% for strain ACCC17676. Rare Earth Nitrate could promote the growth of strain ACCC17631, the optimum concentration was 200 mg·L^-1, and had highly significant influence on the activity of strain ACCC17676(P<0.01), the optimum concentration was 400 mg·L^-1. The optimum combination of medium for ACCC17631 was 100 mg·L^-1of Monopotassium Phosphate, 0.03% of Fulvic Acid and 200 mg·L^-1 of Rare Earth Nitrates, for ACCC17676 was 300 mg·L^-1 of Monopotassium Phosphate, 0.02% of Fulvic Acid and 400 mg·L^-1 of Rare Earth Nitrates.

Key words: Alfalfa rhizobium, Fulvic acid, Rare earth nitrates, Monopotassium phosphate

摘要：

以紫花苜蓿(Medicago sativa)根瘤菌ACCC17631和ACCC17676为供试菌株,采用单因素试验和正交试验设计,研究了KH₂PO₄、黄腐酸、硝酸稀土对苜蓿根瘤菌活性的影响,以期得到最优培养基材料组合.结果表明:KH₂PO₄可极显著促进紫花苜蓿根瘤菌菌株ACCC17631的生长(P<0.01),最适添加浓度为300 mg·L^-1,对菌株ACCC17676的生长促进效果不显著;黄腐酸对2株菌的生长具有极显著促进作用(P<0.01),菌株ACCC17631的最适添加浓度为0.03%,菌株ACCC17676的最适添加浓度为0.02%;硝酸稀土可促进菌株ACCC17631生长,最适添加浓度为200 mg·L^-1;低浓度硝酸稀土对菌株ACCC17676具极显著生长促进作用(P<0.01),最适添加浓度为400 mg·L^-1.菌株ACCC17631最优材料组合为100 mg·L^-1 KH₂PO₄、0.03%黄腐酸与200 mg·L^-1硝酸稀土;菌株ACCC17676的最优材料组合为300 mg·L^-1 KH₂PO₄、0.02%黄腐酸与400 mg·L^-1硝酸稀土.

关键词: 苜蓿根瘤菌, 黄腐酸, 硝酸稀土, 磷酸二氢钾