Repeatability, genetic variability and importance of forage traits in ecotypes of Brunswickgrass (Paspalum nicorae Parodi) via BLUP

Abstract

This study estimated the repeatability of forage traits in 84 Paspalum nicorae ecotypes using six statistical methods and quantified the minimum number of harvests needed for effective selection. Multivariate analyses based on best linear unbiased prediction (BLUP) values were also performed to assess genetic variability, identify key traits and select superior parental genotypes. The randomized complete block experiment, with four replicates, evaluated 12 traits: number of tillers (NT), fresh matter (FM), leaf dry matter (LDM), stem dry matter (SDM), inflorescence dry matter (IDM), total dry matter (TDM), leaf-to-stem ratio (LSR), harvest index (HI), cold tolerance (CT), forage persistence (FP), growth habit (GH) and plant height (PH) over 3 years. Repeatability varied across methods, with the principal component methods based on correlation matrices yielding the highest accuracy. Repeatability was low for LDM, SDM, LSR and PH; moderate for FM, IDM, HI, CT and FP; and high for NT, TDM and GH. Early selection for NT, LDM and TDM traits is feasible with two to 10 harvests. Multivariate clustering identified ecotypes N3.17 and N3.10 as promising parents. The TDM, PH, LSR and CT traits were most discriminative for agronomic characterization.