光萼女娄菜种子成熟时期对萌发特性的影响

Effect of ripening time on seed germination traits of Melandrium firmum (Sieb. et Zucc.) Rohrb.

为了解不同成熟时间对光萼女娄菜种子休眠和萌发特性的影响，测定了种子大小、吸水特性以及种子萌发对温度和光照的响应，以阐释种子成熟时间格局对植物在温带内陆环境中的适应策略．结果表明，种子大小随着种子成熟时间延后而逐渐增加；种皮具有透水性，08-03和09-30成熟的种子在吸水后48h开始萌发，其它时期成熟的种子在吸水60h后开始萌发．种子萌发率随种子成熟时间的延后而降低；种子最适萌发温度范围在10～30℃，完全黑暗条件抑制萌发．种子具有生理休眠特性，种皮划破处理可以显著提高种子萌发率，但是赤霉素处理对萌发没有促进作用．

The primary aims of this study were to investigate the effect of ripening time on seed mass, dormancy and germination traits of M. firmurn in order to elucidate adaptive strategies of this species in the temperate inland environment. Mature seeds that were collected in different times were incubated in different temperature regimes and light conditions. The results showed seed mass increased with the de- lay of ripening time. Seed coat was permeable to water seeds ripening on August 3rd and September 30th began to germinate within 48 h after the imhibition of water, while seeds ripening on other dates began to germinate within 60 h after the imbihition of water. Seed germination percentage decreased with the delay of ripening time. The optimal temperature range for germination was 10℃ to 30 ℃ in light but seed did not germinate in complete darkness. Seed germination was significantly increased by seed coat scarification but not by GA3 treatment, suggesting that seeds were physiologically dormant.