The use of isozymes and RAPD markers in the quantification of the genetic diversity in natural populations of Esenbeckia leiocarpa Engl.

Author(s)

Milene da Silva Castellen

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2001-01-26
• Advisor: Paulo Yoshio Kageyama

Abstract

The objective of this work was to quantify the genetic variability distribution in natural populations of Esenbeckia leiocarpa, through RAPD markers and isozymes. With these objective two subpopulations were selected in four forestry fragments in the São Paulo State and analyzed using RAPD markers. Besides this, the quantification of the genetic variability through isozymes was done in populations of two forestry fragments, in order to compare the obtained parameters through two types of markers: isozymes and RAPD. The results obtained, show a concordance with earlier works with the same specie (Seoane, 1998) through isozymes in two forestry fragments: lbicatu and Caetetus; indicating that the larger part of the genetic variation is found within the populations. This data comes to be added to a series of works with tropical tree species that affirm that the larger part of the genetic variation occurs within the populations. The specie has presented high levels of heterozygosity in all populations, estimated through both techniques. The high intrapopulation genetic variability and the values found through the analysis of variance of the gene frequencies showed that the endogamy values are low, demonstrating signs of the absence of population structuring. This results allied to the adherence to the suitability to the HW equilibrium, demonstrated that the specie does not find itself under the Walhund effect. ln relation to the comparison done among the parameters obtained through both of the methodologies, the results demonstrated that there is a concordance among the parameters obtained through both methodologies except in the heterozygosity values, where factors such as the dominance of the RAPD marker and the assumption of the HW equilibrium, may have affected the estimates. (AU)