不同pH值土壤浸提液对苜蓿种子发芽和幼苗生长的影响

在10个不同pH值土壤浸提液处理下，研究了对不同紫花苜蓿（Medicago sativa L.）品种种子发芽和幼苗生长的影响。试验结果表明：在低pH值或高pH值浸提液处理下，各品种紫花苜蓿种子发芽受到显著抑制；pH值为6.17、8.76、9.20时，虽抑制苜蓿种子发芽，但能够促进已发芽苜蓿种子的生长；发芽率、幼根长度与幼苗高度的比适宜用作鉴定苜蓿耐酸碱性的指标；pH值在5.81～8.44时，各苜蓿品种的平均发芽率都在60%以上，能够正常生长；根据回归方程得，苜蓿生长的临界pH为5.06或9.17，极限pH为2.71或10.26；耐酸碱性强的苜蓿品种有中苜1号、公农2号和霍普兰德。

Effect of soil extracts with different pH values on the germination and seedling growth of alfalfa

The effect of soil extracts with different pH values on the germination and seedling growth of 18 alfalfa varieties was investigated .The germination was inhibited under low or high pH of soil extracts. but when pH values were 6.17、8.76、9.20, the seeds had germinated could be promoted growth to some extent. The germination rate and ratio of seedling height to root length were regarded as two suitable acid and alkali resistance indexes, but the fresh weight was not. The proportion of germination in the substrate with pH values from6.43 to 8.44 was higher than 60%,and the seedling could grow normally. The critical pH was 5.06 or 9.17,and limiting pH was 2.71 or 10.26 through regression equation. Based on measured values, the 18 alfalfa varieties could be divided into 4 groups by AVERAGE cluster analysis. The results showed that Zhongmu No.1,Gongnong No.2 and Hopeland were most acid and alkali resistance.