不同生境下陇东苜蓿种子产量和休眠特性的研究

Seed yield and dormancy characteristics of Longdong alfalfa in different habitats

对甘肃陇东(环县)、陇中(定西)、河西(张掖和酒泉)3地区种植的陇东苜蓿种子生产性能和休眠特性的研究结果表明,种子产量最高的是张掖和酒泉地区,平均产量942kg/hm2,其次是环县,产量最低的是定西,平均301kg/hm2。种子产量与其构成因素的相关性在不同生境下的表现基本一致,相关性强弱依次为:生殖枝数/m2>荚果数/生殖枝>粒数/荚>千粒重。种子的生活力、发芽率和硬实率在地区间的变化趋于一致;在生活力均衡的情况下,定西新收获种子的硬实率显著高于其他地区,发芽率显著低于其他地区。种子在自然条件下贮藏1年,与贮前相比生活力无显著变化,硬实率显著下降,发芽率显著提高;张掖和酒泉种子的硬实下降率为45%～49%,种子最终发芽率达到63%～76%,不经破除硬实即可作为播种用种子,种用价值高于其他地区。

Field studies were conducted in three regions of the Gansu province; including, Huanxian, Longdong; Dingxi, Longzhong; and Zhangye and Jiuquan, Hexi, to analyze the seed yield and dormancy characteristics of Longdong alfalfa (Medicago sativa cv Longdong). The average seed yield in Zhangye and Jiuquan was the highest with a mean of 942 kg/hm^2, followed by Huanxian, and the lowest seed yield was at Dingxi with mean yield of 301 kg/hm^2. The correlation coefficients between seed yield and its components were similar in different habitats. The major seed yield components in order of decreasing importance were reproductive shoots/m^2, pods/reproductive shoot, seeds/pod, and thousand seed weight. Seed viability, hard seed percentage, and germination percentage showed similar variation between the three regions. In the situation where seed viability was similar among regions, the hard seed percentage of newly harvested seeds in Dingxi was markedly higher than in other regions, and germination percentage markedly lower. Comparing seeds that had been stored under natural conditions for one year with those that had not been stored, seed viability showed no significant difference, hard seed percentage showed a significant drop with storage, and germination percentage showed a significant increase. Reduction in hard seed percentage in Zhangye and Jiuquan was the greatest at 45%～49%, and germination percentage increased to 63%～76%. The hard seeds that did not break open could be used for sowing, and their practical seed value was greater than that of seeds of other regions.