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Genetic diversity analysis in Bromus auleticus trinius

Bromus auleticus is a native forage grass extensively disseminated along the Temperate South American Continent occuring, however, with low frequency in the natural grassland. It shows a significant vegetative growth during Autumn-Winter months which are critical for cattle due to the low productivity of the native pastures, what turns it to be a potentialy interesting forage grass to be introduced in the field. Fourty six entries of B. auleticus from Uruguay are avaliable at the Germoplasm Bank of the Centro de Pesquisa de Pecuária dos Campos Sulbrasileiros - CPPSUL - EMBRAPA, in Bagé, RS. The aim of this work was to analyse the genetic diversity among more productive B. auleticus entries. The results of this analysis is useful for planning and establishment of a plant breeding program for this specie. Width and pilosity of both leaf faces were measured and open polinated plants obtained from one individual of each entry. The genetic diversity was analysed by phenotipic diversity index (H') for both morphological characteristics mentioned and the entries were compared using the Student t test. Higher phenotipic variability was observed for leaf width as expected from polygenic traits but the leaf pilosity showed to be the best genetic marker permitting to distinguish four access pairs. The traits used, however, were not considered appropriate to revel the genetic diversity reserve and not yet explored for genetic improvement.

variability; forage grass; morphological markers


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