Genetic diversity based on morphological data in Panicum maximum hybrids

Abstract

-The objective of this experiment was to evaluate the genetic divergence between hybrids obtained from 10 sexual genitors of the Panicum maximum breeding program at Embrapa Beef Cattle. For this, the following morphological descriptors were used: plant height, growth habit, leaf aspect, leaf waxiness, hair density on the sheath (DePB) and blade (DePL), degree of hardiness of the hairs on the leaf sheath (DuPB) and blade (DuPL) and length of hairs on the sheath and blade. The characteristics growth habit and waxiness were not included in the analysis for being invariant. The phenotypic correlations were low and, therefore, not used to eliminate variables. By the principal component analysis, an 84.3% accumulation of the variation was observed until the fourth component. The last four principal components presented an estimate lower than 0.7 and allowed the identification of the variables DePB, DuPB and DuPL as the least important for diversity studies. The morphological characters used were not efficient to distinguish the progenies, but allowed the formation of morphological groups that converged with the graphic analysis of the principal components. An apparent error rate of 17.04% was observed in the classification of the individuals in the groups and 55.5% in the classification of the individuals in the progenies. The individuals in the P. maximum half-sib progenies are genetically divergent, but may not be grouped with only the descriptors used in this experiment. The pubescence characteristics were the least important in the discrimination of the genotypes.

Genetic diversity of a Paspalum notatum Flügge germplasm collection

“…Studies of morphological variation in plants are a useful tool in genetic improvement programs and enable access to the genetic variability within a germplasm bank (Azevedo et al 2011;Martuscello et al, 2012). In plant breeding programs, knowledge of variability and genetic diversity within a species is essential for the rational use of genetic resources (Govindaraj et al, 2015).…”

Ataque e Caracterização de Danos de Brevicoryne brassicae (L.) (Hemiptera: Aphididae) em Brachiaria decumbens Stapf e Panicum maximum Jacq.

“…Brasil apresenta cerca de 172 milhões de hectares de pastagens, que correspondem a quase 22% de seu território (Martuscello et al 2012). Aproximadamente 90% dos nutrientes consumidos pelos ruminantes são originados a partir de plantas forrageiras (euclides et al 2010).…”

Understanding the extent of phenotypic variability in accessions of Paspalum urvillei Steud. from the USDA NPGS

“…For example, Tuhina-Khatunm et al (2015) show the importance of determining genetic variation based on morphological traits. Recent articles published by Martuscello et al (2012), Pereira et al (2012), Rocha et al (2017) and Kaur et al (2018) showed the importance of genetic variability and detected high variability in forage species based on zootechnical traits. In this way, some biometric strategies, including data processing using principal component analysis, principal coordinate analysis, and group structure approaches, stand out as useful options for understanding trait relationships in a population.…”