| Abstrakt: |
Pollen morphology and the reproductive biology of Calophyllum brasiliense were investigated in Parque Estadual das Fontes do Ipiranga, São Paulo, Brazil. The study encompassed pollen analyses using light, scanning, and transmission electron microscopy. Additionally, we collected data on reproductive biology, main visitors/pollinators, fruit set, and seed germination. The species exhibits individuals with perfect flowers (hermaphrodites) as well as male individuals with staminate and perfect flowers. Flowering occurs in October and November, and flowers have diurnal anthesis and pollen as a floral resource. Pollen grains are monads of medium size, isopolar, oblate-spheroidal to prolate-spheroidal, 3-(4)-zonocolporate, with exine fossulate-perforate with supratectal microechini. Hermaphrodite individuals have the highest proportion of malformed pollen due to their reduced grain size. The pollen grains from the hermaphrodite individuals displayed a low viability (0.06%), while those from male individuals had higher viability (66.38% and 55.78% for perfect and staminate flowers, respectively). The stigma was receptive throughout the anthesis period. Cross-pollination between perfect flowers of male and hermaphrodite individuals resulted in 8.80% success in fruit set, but led to the development of one abnormal seedling. Cross-pollination between staminate flowers and perfect flowers of hermaphrodite individuals showed a 7.70% success rate and the control group showed an 8.00% success rate, both groups leading to the development of normal seedlings. This tree species shows relatively low reproductive success and relies on pollinators (mainly Apis mellifera, Paratrigona subnuda, Tetragonisca angustula, and Halictidae sp. 1) for the setting of fruits and seeds. [ABSTRACT FROM AUTHOR] |
