Reproductive biology of Spondias bahiensis P.Carvalho, Van den Berg & M.Machado (Anacardiaceae) in Recôncavo da Bahia

Abstract

Spondias bahiensis, commonly called umbu-cajá, is native to Brazilian semiarid areas and is an important economic plant in the country’s Northeast region. The study of its reproductive biology is essential to understand phenomena related to seed and fruit formation and the environment in which the plants are embedded. Here we describe the reproductive biology of Spondias bahiensis under conditions of Recôncavo da Bahia. Pollen grain viability was assessed through histochemical tests and in vitro germination. Stigma receptivity was determined using a hydrogen peroxide and α-naphthyl acetate solution. The reproductive systems were examined in the field and classified as autogamous and self-incompatible. We observed floral visitors for 150 hours. The average time between flowering and fruit harvest was approximately 180 days. The species blooms from September to December and fruits from October to December. Spondias bahiensis presents hermaphrodite and staminate flowers. Anthesis is diurnal, starting at 4 a.m. We noted high percentages of pollen grain viability. Stigmatic receptivity occurs concurrently with anthesis and lasts for over 24 hours after floral opening. The main floral visitors are bees. The species is self-incompatible and preferentially allogamous, with a tendency to be self-sterile and dependent on pollinators. The knowledge acquired from this study enables formulating strategies for conservation of the species and developing genetic improvement programs, besides helping to consolidate productivity and fruit quality, thus expanding the market, increasing the value of the products and enabling the establishment of organized commercial plantations.