Biologia floral e reprodutiva de espécies nativas de cactáceas

Abstract

Caatinga has great ecological, social and economic importance for our country, due to its high genetic variability and great diversity of cacti. The objective of this work was to study the reproductive biology of Pilosocereus pachycladus, Cereus jamacaru (DC) and Xiquexique gounellei. The field experiments were conducted in a natural population in the municipality of Bananeiras - PB. The laboratory tests were conducted at the Biology Laboratory of the Center for Human, Social and Agrarian Sciences, Campus III of the Federal University of Paraíba. This work was systematized in two chapters with the following approach: Chapter I - Floral biology of native cacti: Facheiro Pilosocereus pachycladus subsp. pernambucensis, Mandacaru (Cereus jamacaru (DC) and Xique xique (Xiquexique gounellei) in a natural population in the municipality of Bananeiras - PB; Chapter II - Pollen viability of Facheiro, Mandacaru and Xique xique. From October 2018 to April 2019, Facheiro presented the flowering and fruiting phenophas throughout the study period. Mandacaru presented flowering and fruiting peaks, with low flower buds and flowers being observed. Such phenomenon may be related to the rainy season, in which the plant can respond with emission of flowers in the period of greatest water availability. The xique-xique showed seasonal flowering, with fruit production from January to May 2019. The flowering of P. pachycladus, is continuous with peak of flowering in October and November of 2018. The species of pachycladus Subsp, C. jamacaru and X. gounellei, have hermaphrodite flowers. P. pachycladus presented the largest ovary diameter among the studied species. The pollen viability for Facheiro, Mandacaru and Xique xique was 93.86%, 99.44% and 99.54% respectively, the pollen / ovule ratio was 847/1, 455/1 and 1533/1. The flowers showed high pollen viability, the reproductive system of the species points to facultative xenogamics.