Morphological and anatomical development in the Vitaceae.

摘要

A comparative developmental study of selected members of the Vitaceae, using three-dimensional and histological techniques is presented. The species examined were Vitis riparia, Parthenocissus inserta, and Ampelopsis brevipedunculata. This study is the first one in which the phenology, developmental morphology, and anatomy of the shoot have been followed in uncultivated plants in this family. It is the first comparative study of floral development in the family, and the first to integrate this with vegetative development. The study concentrated on: (1) the developmental pattern and interpretation of the shoot; (2) the pattern of floral development; and (3) lateral bud development. A new analysis of the shoot designates primordia initiated at the shoot apex as: Type 1, a leaf initiated at a lower tendril node; Type 2, a leaf initiated at an upper tendril node or a tendrilless node; Type 3, a lower uncommitted primordium; and Type 4, an upper uncommitted primordium. An "uncommitted" primordium is defined as a shoot homologue which arises opposite a leaf, and at a developmental stage at which it is morphologically impossible to predict its fate (tendril, inflorescence, or intermediate). The question of whether or not the vitaceous shoot is monopodial or sympodial is inappropriate. It is monopodial in an ontogenetic sense, and sympodial in an evolutionary sense, and should be interpreted from a complementary perspective. There is a familial tendency towards precocious development of axillary organs: (a) the main and lateral arm of the uncommitted primordium may originate almost simultaneously; (b) the inflorescence branch may originate before its subtending bract; and (c) the stamens and petals arise from their common petal/stamen primordium almost simultaneously. The ring primordium that subtends the sepals may develop prior to completion of sepal initiation. This tendency is greater in Vitis than in Ampelopsis. Two types of bud complexes were encountered: (1) those in which each bud originates in the axil of the prophyll of the previous bud; and (2) those in which a vertical series of axillary buds arises basipetally. In both types the first bud develops sylleptically and the others develop proleptically.