Vegetative propagation as a successful reproductive strategy in woody dioecious species in tropical coastal vegetation, southeast Brazil

Abstract

Dioecious plant populations are composed of two distinct sexual morphs representing the female and male counterparts. Dioecy in restinga areas has been strongly associated with fleshy fruits, woodiness, generalist entomophily, and resource-poor environments. The ability of vegetative reproduction is another ecological trait commonly associated with dioecy, but not shown for the woody dioecious species in restingas. This study aimed to investigate whether the distribution of sexual morphs in populations is due to occurrence of vegetative propagation as a reproductive strategy among dioecious woody species on sandy coastal plains. We also intended to evaluate possible effects of sex ratio on sexual reproduction (female reproductive success). The study was conducted in the sandy coastal plains (restinga) of Marica, Rio de Janeiro State. We studied six woody dioecious species. During the reproductive period, all individuals of each species and your nearest neighbor were marked using GPS, along an area with approximately 5.1 ha. The sex of the individuals was recorded. This study provides evidence of the occurrence of vegetative propagation in the woody dioecious species studied and indicates that the ability to reproduce in this manner varies between sexual morphs, generating male-biased populations in most cases. Our data suggest that asexual reproduction by vegetative propagation of the male morphs can have an effect on sexual reproduction, as it increases the amount of staminate flowers, and therefore the supply of the pollen grains. Our results provide insights into vegetative reproduction as a strategy to increase male plant fitness and an alternative to populate environments under stress.