玉簪花序水平上雌性适合度成分变化及种子数量与大小权衡关系研究

研究了碧峰峡自然保护区多年生草本植物玉簪花序水平上雌性适合度成分变化.玉簪每花胚珠数由基部向顶部逐渐降低.在自然条件下,每果结籽率由基部向顶部增加,每果种子数以中部最高,基部最低.每果单粒种子重量由基部向顶部降低,以基部最高.而每果种子总重不依赖于部位而变化.每果种子数与每果单粒种子均重存在权衡关系.

Intra-inflorescence Variation in Female Fitness Components and Seed Size-Number Trade-off in Hosta plantaginea (Liliaceae)

Intra-inflorescence variation in female fitness components in the perennial hermaphrodite herb Hosta plantaginea(Liliaceae)was examined in Yaan Natural Conservation Park.Ovule number per flower declined from the basal to the distal positions within the inflorescences.Under natural conditions,seed-setting per fruit increased from the basal to the distal positions,seed number per fruit was the highest at the middle positions and the lowest at the basal positions.Mean seed weight per fruit was maximum at the basal positions and declined from the basal to the distal positions,whereas total seed weight per fruit was independent of the relative floral position.A weak but significant negative relation was present between seed number per fruit and mean seed weight per fruit,indicating a trade-off.