Conservação ex situ e biologia reprodutiva da espinheira santa (Maytenus ilicifolia, Celastraceae)

Abstract

Espinheira-santa (Maytenus ilicifolia) is a medicinal plant native in Brazil. It is used in the treatment of gastritis and gastric ulcers. To conserve the genetic variability of this species, 129 accessions from 15 municipalities of Rio Grande do Sul State, Brazil, are conserved in the Active Germplasm Bank of Espinheira-Santa by Embrapa Clima Temperado in partnership with the Instituto Federal Sul-rio-grandense. This thesis had the objective to contribute to the advancement of knowledge related to the reproductive biology of M. ilicifolia. Evaluations were made of floral biology, reproductive phenology, reproductive system, pollinators and seed dispersers. The phenophases of flower bud, floral anthesis, ripe and immature fruit were evaluated monthly. Floral visitors were observed in the period of flowering and were classified in pollinators or nectar scavengers. The birds consuming fruit were registered at the time of ripening, and those that swallowed the whole diasporas (aril and seeds) were considered dispersors of seeds. The flowers have diurnal anthesis, are morphologically hermaphrodites, they are similar in size, shape and coloration, but exhibit behavior of functionally female flowers (producing fruit), or functionally male flowers (producing pollen), rarely hermaphrodites. Both floral morphotypes produce ovules and pollen, and the stigma is receptive. The ovary of the functionally male flowers does not produce fruit. Pollen is fertile in both floral morphotypes. However, pollen was not present in 37% of the anthers in functionally female flowers, and only four grains were recorded on the other flowers.The functionally male and female flowers occur on different plants, characterizing this species as functionally dioecious. Only functionally female flowers pollinated with pollen from other flowers set fruit bycross-pollination and geitonogamy, characterizing autoincompatibility in espinheira-santa. The reproductive period occurred from June, with the emission of flower buds, until February, with the maturation of the fruit. The pollinators are the flies, mainly Lucilia eximia and Limnophora sp., and wasps, especially Brachygastra melifica, Polistes canadensis and a species of Tiphiidae family. Eight species of birds consumed diaspores, acting as dispersors, standing out the Tangara sayaca, Elaenia sp. and the Pipraeidea bonariensis. M. ilicifolia is an allogamous species, showing floral morphology compatible with entomophilous and generalist pollination. The reproductive phenophases are correlated with temperature and length of the day, and the beginning of bloom depends on the latitude. This thesis contributes to the advancement of knowledge of the reproductive biology of espinheira-santa, featuring relevant information to the conservation and use of this important genetic resource.