Evolutionary and ecological estimation of fruit structure in monocotyledonous plants of the flora of Ukraine

Abstract

Background. Monocot plants in the flora of Ukraine embrace about 1000 species. The members of this group have various fruit types and ways of dissemination. In this review, the results of the evolutionary-morphological analysis of fruits in monocot plants of the flora of Ukraine and their structural adaptations to dispersal are presented. Gynoecium structure and morphogenetic fruit types in monocots. The features of the inner gynoecium structure and the relation between gynoecium and fruit structure were analyzed, and the main problems of fruit classification were detected. It was revealed that apocarpous fruits are often polymerous or oligomerous, composed of 3–6 one-seeded fruitlets. The species with inferior ovary often develop capsular fruits. One-seeded fruits represent the most reduced variant of the gynoecium structure and fruit wall anatomy, providing few structural traits for analysis. Ecological and functional features of fruits in monocots. The characteristics of dehiscent and indehiscent fruits, as well as adaptations to various ways of dispersal: myrmeco-, endozoo-, epizoo-, anemo-, hydro- and autochory are presented. Dehiscent fruits (follicle and capsule) reveal ventral, dorsal or double, dorsoventral dehiscence. One-seeded fruits and fruitlets are often adapted to hydrochory or anemochory. Trends of evolutionary changes of fruits in monocots. The most diverse fruits are found in low-species taxa of early monocots. Within the monocots, we can observe certain evolutionary trends: incomplete carpel fusion, the occurrence of superior one-seeded fruits and inferior many-seeded fruits. Each of these trends may be evoked by adaptations for pollination in gynoecium at the flowering stage. Conclusions. The present evolutionary morphological and ecological studies of fruits in monocot plants of the flora of Ukraine are impeded by controversial structural types of the gynoecium in some species and a scarcity of data on ways of dispersal of fruits and seeds. The precise carpological and carpoecological investigations of the monocots are desirable for many plants of the flora of Ukraine. Keywords: gynoecium, carpel, inferior ovary, fruit wall, adaptation, fruit dehiscence