The Preliminary Research of Correlations between Stones Morphological Variation and Mean Seed Set of Davidia

Chinese dovetree (Davidia),which is listed as one of the National First-class state-protected species in China,is the relict of atertiary paleotropical kingdom and a rare species to China.It belongs to Nyssaceae.Low seed set is one of important factors threaten the survival of Davidia.The correlations between morphological variation and mean seed set of dovetree stones in Wolong population and Mianzhu population in 2006 were studied.There was a low negative correlation between length/diameter and mean seed set of Davidia stones collected from Wolong population,r=-0.457;while there was a weak negative correlation between length/diameter and mean seed set of Davidia stones collected from Wolong population,r=-0.188.Gini Coefficient analysis showed that the morphological variation of stones in Wolong population mainly came from the variation of interplants,which was perhaps caused by genetic factor.There were significant differences of mean seed set of stones among interplants,which were perhaps caused by pollen limitation.