Microsporogênese e viabilidade polínica de pitangueira (Eugenia uniflora L.) em fragmentos de Floresta Ombrófila Mista

Abstract

The Eugenia uniflora a member of Myrtaceae family presents a strong economic interest, this can lead to exploitation of the species without adequate planning. Thus become essential of studies of ecological and genetic aspects of the species. Forest fragmentation by reducing the number of individuals in a population favors the loss of genetic variability. Guarapuava, in the Brazil, is a predominantly agricultural county, is very evident the process of forest fragmentation within its topography. Considering the absence of a review on the species and that forest fragmentation can lead to a withering and this may have genetic effects on meiosis, this work aimed a specie review, analysis of microsporogenesis in four Brazilian cherry populations, coming from forest fragments, and to correlate genetic data with reproductive isolation. With the lifting of the available literature was possible to identify a lack of basic studies focused on the ecology and genetic characterization of the species in contrast to the volume of works found on the economical use. The chromosomes in metaphase I showed a precocious chromosomes, anaphase I with chromosome bridges, the metaphase II showed chromosomal plates with irregular orientation to telophase and tetrad showed pentads for all populations and triads for the isolated population. The microsporogenesis was stable for three fragments, presenting the percentage of abnormalities for the meitoc phases, less than 4%. These fragments are connected by riparian vegetation. One fragment showed 13% to 21% of abnormalities in the early stages of microsporogenesis, this fragment is isolated from others and surrounded by farmland. Pollen viability was above 93% for fragments connected and up to 73% for the isolated fragment. The data show that forest fragmentation has influence in meiosis, because the population of the isolated fragment showed a higher percentage of abnormalities and a lower index of pollen viability in relation to populations in fragments connected riparian vegetation.