An evaluation on genetic variability of palisade grass (Urochloa brizantha L.) mutants to subtropical climate condition

Abstract

Gustavo Maputa Deigo

The objective of this study was to evaluate the induction of genetic variability and plant development of palisade grass (Urochloa brizantha L.) M2 mutants in acclimatization to subtropical climate condition. The mutagenic agent methyl methanesulfonate (MMS), at a dosage of 0.5%, was used to induce mutation in 4,000 seeds of the cultivar Marandu. Thirty five plants survived after the induction of MMS mutagen agent. These plants were isolated transplanted in experimental area to advance the generation. Seeds produced by plants were sown in pots allocated in Biosystems Organized Development incubator and subjected to cold stress at 0°C in seedling stage. Surviving seedlings per family were transplanted to field conditions in Southern Brazil. The plant development was evaluated in the M2 generation during the agricultural years of 2012-2013 and 2013-2014. Genetic variability analyzes were carried out with 21 traits, based on the average Euclidean distance and the relative contribution proposed by Singh (1981). Chemical mutation induction with MMS generates genetic variability in palisade grass, enhancing the selection of superior genotypes in subtropical climate conditions. The chemical induction of mutations with the MMS mutagen provided genetic variability in the population of U. brizantha with formation of 18 divergent groups during the research.