Contemporary gene flow, intrapopulation spatial genetic structure and hierarchical mating system within and between fruits in a small isolated population of Genipa americana L. using microsatellite markers.
Studies of the mating system, genetic isolation of populations and the distance and the dispersal patterns of pollen and seeds are fundamentals for to understand the effects of forest fragmentation on population genetic of tree species. These studies permit to detect the effects of reproductive isolation, loss of genetic diversity and increase in the population inbreeding, as well as to define strategies for in situ conservation, germoplasm sampling for ex situ conservation and seed collect for environmental restoration. Within this contest, the aims of this project are to study by microsatellite markers the genetic diversity, the mating system, the degree of genetic isolation, distance and patterns of pollen and seed dispersal, the spatial distribution of genotypes and the effective size of a small population of Genipa americana located in a fragment of 7.2 ha. The fragment is located in Mata da Figueira, in the Experimental Station of Mogi-Guaçu, of the Forestry Institute of São Paulo. For this, all 169 adult trees existing in population will be mapped, will have the diameter at breast height (DBH) measures, leaf tissue sampled for genetic analysis and sex determination (male and female). To study the dispersal of pollen and seeds, and isolation of the population by analysis of kinship, intended to map, measure the height and samples leaves from 300 seedlings of regeneration. Open pollinated seeds will also be collected of ten trees, 50 seeds per tree in two reproductive events (2011 e 2012), being ten seeds per fruit (five fruits per tree). Seeds from the reproductive event of 2011 was already collected. To detect the effects of fragmentation on generations of descendants, the genetic diversity, inbreeding and effective size will be compared between adults, seedlings and seeds. The spatial genetic structure also will be compared between adults and seedlings in order to verify if is causing increase in kinship in the population. These results will allow understand the contemporary process of reproduction after genetic isolation by forest fragmentation and its impacts on the effective size of the generations descendants of populations of G. americana, and, thus, will serve to outline strategies for the conservation and seed collection for the environmental recovery of the population.
News published in Agência FAPESP Newsletter about the scholarship: