Changes in leaf morphology of grape seedlings during transition from the juvenile to adult phase

Abstract

The relationship between the formation of tendrils and leaf morphology was investigated in the seedlings of a wild grape, Ebizuru [Vitis ficifolia Bunge vat. lobata (Regel.) Nakai], 'Campbell Early' (V. labruscana Bailey) , and 'Kyoho' (V. labruscana Bailey). All grapes tested had a 144° spiral phyllotaxis before the formation of tendrils (juvenile phase), but alternate phyllotaxis after the formation of tendrils (transition phase). The morphology of the leaves represented by Galet's index did not differ before and after tendril formation. However, the number of serrations at the leaf margin increased at the higher nodal position before tendril formation. The node numbers bearing the first tendril were 26.8, 28.7, and 30 in the seedlings of Ebizuru, 'Campbell Early', and 'Kyoho', respectively. The number of serrations per leaf increased gradually after the formation of tendrils (adult phase) in the seedlings of 'Campbell Early' and 'Kyoho', but very slowly in Ebizuru. The serration grew deep and their angles became small with each succeeding nodal position. The depth of the sinus before and after tendril formation did not differ between seedlings of 'Campbell Early' and 'Kyoho', but it increased after the tendril formation in Ebizuru.