Abstract:

Viola philippica is a typical dimorphic cleistogamous species with the chasmogamous- cleistogamous mixed breeding system. No visible morphological difference were found between chasmogamous and cleistogamous flower development before 4 rounds floral organs primordium formation. The development stage of significant difference appeared at the stage of the sporogenous cell after floral organs primordium occurred. During late developmental stage of flower buds，5 petals and 5 stamens were all continue growing，and each anther had 4 locules in chasmogamous flower. But only 2 stamens continued development，other stamens and all petals still stayed the primordium state，and each anther had 2 locules in cleistogamous flower. The content of soluble sugars and starch in the floral buds was on the up trend with the development of flower in chasmogamous and cleistogamous plants from the second stage to the fifth stage. The content of either soluble sugars or starch in chasmogamous flowers was all higher than the cleistogamous flowers in corresponding development stage. But the content of soluble sugars and starch in the leaf of chasmogamous plants were less than the leaves of cleistogamous plants. The results showed that the investment of energy in chasmogamous flowers was higher than the cleistogamous flowers. We suspected there were some correlation between the content of soluble sugars and starch and the dimorphic flower development.

Key words: Viola philippica, flower development, chasmogamous flower, cleistogamous flower, sugar, starch