Abstract: To explore the major factors influencing seed germination ability and determine the best harvest time for the seeds of Melilotus dentatus,the changes of its seed structure,yield and quality were observed and determined in different mature stages in this experiment. The results indicated that the thickness of palisade cell layer and osteosclerid cell layer,hard seed percentage,yield,1 000-grain weight and viability of Melilotus dentatus seeds increased as seeds mature in the field,and their maximum values were found in full ripe stage,and the hard seed percentage was positively correlated with the thickness of palisade cell layer and osteosclerid cell layer of seed coat. The germination energy and germination percentage of Melilotus dentatus seeds increased at the beginning and then decreased as seeds mature,and their maximum values were found in the 5^th day after early yellow ripe stage. After scratch treatment,the germination energy and the germination percentage of Melilotus dentatus seeds in different mature stages increased greatly,among which the germination energy and the germination percentage of seeds collected in full ripe stage increased from 7.50% and 8.00% to 96.00% and 96.75%,respectively. In conclusion,the hardness of seed coat was the main factor influencing seed germination of Melilotus dentatus,and the degree of seed coat hardness may be caused by the thickness of palisade cell layer and osteosclerid cell layer. Full ripe stage was the optimal harvest time for seeds of Melilotus dentatus in alar city of Xinjiang,and the hard-seededness must be broken down when used as seed material.

Key words: Melilotus dentatus, Seed structure, Hardness, Seed yield, Germination ability

摘要： 为了探索影响细齿草木樨(Melilotus dentatus Pers.)种子发芽力的主要因素，确定适宜的种子收获时间，本试验对不同成熟阶段细齿草木樨的种子结构、产量和质量进行了观察和测定。结果表明:随着细齿草木樨种子成熟，其栅栏细胞层厚度、骨状石细胞层厚度、硬实率、产量、千粒重和生活力呈上升的变化趋势，于完熟期达到最大值，其中硬实率与种皮栅栏细胞层厚度和骨状石细胞层厚度呈正相关；细齿草木樨种子的发芽势和发芽率呈先升后降的变化趋势，于黄熟前期后第5 d达到最大值；划痕后，细齿草木樨种子的发芽势和发芽率大幅提高，在完熟期分别由7.50%和8.00%增至96.00%和96.75%。综上所述，种皮硬实是影响细齿草木樨种子萌发的主要因素，其硬实程度可能取决于栅栏细胞层厚度和骨状石细胞层厚度。细齿草木樨在新疆阿拉尔市最适宜的种子收获时间为完熟期，用作播种材料时，必须先破除硬实。

关键词: 细齿草木樨, 种子结构, 硬实, 种子产量, 发芽力