Abstract

CASTRO, H.G et al. Genetic divergence study by morphologic traits among mentrasto (Ageratum conyzoides L.) accessions collected in the state of Tocantins in different period. Rev. bras. plantas med. [online]. 2011, vol.13, n.1, pp. 24-29. ISSN 1516-0572.  http://dx.doi.org/10.1590/S1516-05722011000100004.

This study aimed to analyze the genetic divergence among nine mentrasto (Ageratum conyzoides) accessions by multivariate methods using morphologic traits for four harvesting periods. The nine accessions of mentrasto were obtained from plants that occur naturally in five climatic regions of the state of Tocantins. At each harvesting period, the following traits were evaluated: fresh biomass of the aerial part, dry biomass, leaf area, number of leaves, flowering and height. The grouping analysis (Tocher's method) identified two groups, in the first and fourth harvest periods, three groups in the second harvest period and four groups in the third harvest period. Variation was observed for the group constitutions among the different harvesting periods. The genetic divergence among mentrasto accessions, evaluated by morphologic traits, was influenced by developmental stage of specie. The existence of genetic variability among accessions from different regions supports the systematic collection of A. conyzoides germplasm in the state of Tocantins.

Keywords : plant genetic resources; genetic divergence; Ageratum conyzoides; multivariate methods.