紫花苜蓿低温萌发特征及指标筛选

Effects of low temperature on seed germination characteristics of alfalfa (Medicago sativa)

低温抑制高寒地区晚秋和早春播种苜蓿快速整齐萌发,影响苜蓿人工草地的成功建植.为了探索苜蓿种子的低温萌发特性,为田间播种提供依据,选择国内外6个紫花苜蓿品种进行标准发芽温度(20℃)和低温(4℃)萌发试验,测定相应的发芽指标.结果表明:低温萌发苜蓿品种间存在着显著差异,且品种间各发芽指标低温响应不同.中科1号耐低温发芽率最高,中科2号低温下根长生长最快.主成分分析结果表明,主成分1可解释5个发芽指标64.18%的变异,根据主成分1,各品种低温萌发得分中苜1号、中科2号、中科1号、WL363、草原3号、敖汉依次降低.该结果为早春和晚秋低温条件下苜蓿播种提供了依据.

Suppression of seed germination of alfalfa(Medicago sativa)by low temperature in early spring and late autumn of alpine regions often limits seedling establishment.To study seed germination characteristics of alfalfa under low-temperature incubation conditions,6 varieties(Zhongke No.1,Zhongke No.2,Aohan,Zhongmu No.1,Caoyuan No.3,WL363)were incubated under standard temperature(20℃)and low temperature(4℃),and the germination indexes were determined.The results showed significant differences in seed germination indexes among the alfalfa varieties.Compared to standard temperature incubation,exposure to low temperature had no significant effects on germination percentage of Zhongke No.1.Root elongation of Zhongke No.2 was the least inhibited among the 6 alfalfa varieties by low-temperature incubation.The principle component analysis revealed that principle component 1 accounted for 64.18%variation of the 5 measured germination indexes.Based on the principle component 1,the score of 6 varieties was decreased as Zhongmu No.1,Zhongke No.2,Zhongke No.1,WL363,Caoyuan No.3 and Aohan.These results provide important guidance for sowing alfalfa in early spring and late autumn of alpine regions.