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

Abstract

The objective of this study was to investigate the phenotypic variability in Paspalum urvillei Steud. related to twelve zootechnical traits to better understand the diversity of 41 accessions from the USDA GRIN platform from seven countries. First, we performed a structure inference based on the phenotypic data, identifying two structure groups, and the majority of Brazilian accessions belonged to the first group. Then, we performed principal component analysis and principal coordinate analysis, making Violin plots for each trait within each structure group. Next, we performed spatial clustering of the accessions and utilized an unweighted pair group method with arithmetic mean clustering. In brief, the Brazilian P. urvillei breeding programs may be successful by importing USDA germplasm resources from the second phenotypic structure group.Keywords: cluster analysis, germplasm bank, forage RESUMO -Entendendo a extensão da variabilidade fenotípica em acessos de Paspalum urvillei Steud. do banco de germoplasma do USDA NPGS. O objetivo deste estudo foi investigar a variabilidade fenotípica de Paspalum urvillei em relação a doze características zootécnicas, a fim de compreender melhor a diversidade de 41 acessos da plataforma USDA GRIN de sete países. Primeiro foi realizada uma inferência de estrutura baseada nos dados fenotípicos, identificando dois grupos estruturados, onde a maioria dos acessos brasileiros é inferida ao primeiro grupo. Em seguida, examinou-se a análise de componentes principais e análise de coordenadas principais, foram feitos gráficos de violino para cada característica dentro de cada grupo estruturado. Por fim, foi realizado o agrupamento espacial dos acessos e o método de médias não ponderadas de grupos pareados. Em suma, o programa brasileiro de melhoramento de P. urvillei pode alcançar sucesso importando acessos do USDA inferidos ao segundo grupo estruturado.Palavras-chave: análise de agrupamento, banco de germoplasma, forragem

Genetic Variation

“…Consequently, the evaluation of trait occurrences and differences in a population is a key to determining probably valuable crosses among accessions. Although most studies focus on genetic diversity with molecular markers, it is also useful for plant breeders to recognize the morphological diversity of traits of interest [57].…”

Understanding the Geographic Patterns of Closely-Related Species of Paspalum (Poaceae) Using Distribution Modelling and Seed Germination Traits

“…The sexual species of the Dilatata complex share several functional vegetative traits with the very widespread and better studied P. dilatatum . They are perennial warm-season C4 grasses with very high leaf frost tolerance [ 62 , 63 , 64 , 65 ] and minor differences in growth habits [ 12 , 66 ]. Except for P. dasypleurum , no major differences in development or vegetative persistence have been reported for these species in their reciprocal locations when transplanted.…”

Could the Dilatata group of Paspalum be bred as sexual species? A preliminary assessment

“…When first identified, a single line of P. flavescens was used for agronomic evaluations and its performance was inferior to that of the apomictic types (Venuto et al, 2003). More recent studies have evaluated extensive collections of these species, particularly P. urvillei (Ferreira et al, 2020;Sawasato et al, 2008) and P. flavescens (Sandro et al, 2019), showing that genetic variability and breeding potential of these species is far greater than initially perceived. Most agronomic characterizations of sexual tetraploids have focused on P. flavescens (Venuto et al, 2003) and P. plurinerve (Baréa et al, 2007;da Costa et al, 2003) probably because they have been considered the most promising and morphologically similar to the well-known and extensively evaluated apomicts.…”