Variabilidade genética de caracteres forrageiros em Paspalum

Abstract

Resumo -O objetivo deste trabalho foi determinar a variabilidade genética e a expressão de caracteres de interesse forrageiro em espécies de Paspalum. Os experimentos foram conduzidos em diferentes locais e anos de cultivo, em delineamento de blocos ao acaso, com três repetições. Foram avaliados cinco acessos de P. nicorae e dois de P. guenoarum, além da cultivar Pensacola (P. notatum), utilizada como testemunha. Foram quantificados os seguintes caracteres: relação folha/colmo, índice de colheita e massa de matéria seca total, de folhas e de colmo. Tanto os efeitos principais (genótipos, anos e locais de cultivo) quanto a interação entre os fatores tiveram influência significativa sobre os caracteres avaliados. Os acessos avaliados apresentam variabilidade genética em caracteres de interesse forrageiro, bem como desempenho variável de acordo com o local e o ano de cultivo. A produção de matéria seca total e de folhas são os caracteres que mais contribuem para a detecção da variabilidade genética observada, independentemente do ano de avaliação.Termos para indexação: apomixia, espécie nativa, interação genótipo x ambiente, seleção. Genetic variability of forage traits in PaspalumAbstract -The objective of this work was to determine the genetic variability and the expression of traits of interest for forage production in species of Paspalum. The experiments were carried out in different locations and crop years in randomized block design with three replicates. Five accessions of P. nicorae and two of P. guenoarum were evaluated, besides the cultivar Pensacola (P. notatum), used as a control. The following traits were determined: leaf/stalk ratio; harvest index; and total, leaf, and stalk dray matter. Both main effects (genotype, years, and locations) and the interactions among factors had significant influence on the evaluated traits. The evaluated accessions showed genetic variability in traits of interest for forage production, and their performance varied according to the location and year of cultivation. Total and leaf dry matter production are the traits that most contribute to the detection of the observed genetic variability, regardless of the year of evaluation.

Genetic gain in apomictic species of the genus Paspalum

“…In these conditions, native species of the genus Paspalum have advantages over the exotic species because of the greater adaptation and great intra-and interspecific variability in forage-related traits (Pereira et al, 2012;Daurelio et al, 2014).…”

Management of consecutive cuts in the production and quality of wintergreen paspalum seeds

“…Several studies demonstrate the superiority of this group when compared with genotypes Notata and Livida group (Fachinetto et al, 2012). This is the case of the Paspalum guenoarum species, "Azulão" ecotype, that features high levels of total dry matter production (15995 kg/ha -1 ), dry matter from leaves (11218 kg/ha -1 ), high digestibility, and cold tolerance (Pereira et al, 2012). Although it demonstrated excellent results regarding the production and quality of the forage, its diffusion is limited by the scarce availability of seeds in the market and their low quality (Pinto, 1982).…”

Genetic variability of the components of seed yield in interspecific hybrids of Paspalum

“…Other studies have demonstrated the importance of analyzing perennial warmseason grasses over several years (Pereira et al, 2012).…”

“…Most Paspalum species reproduce by apomixis (Quarín and Normann, 1990), hampering genetic recombination and the protection of cultivars under current legal standards (Pereira et al, 2012). However, the use of hybrids, when one of the parent plants exhibits sexual reproduction, can generate variability and enable the selection of elite progeny, with immediate fixation of characteristics of interest due to apomixis (Acuña et al, 2009).…”