Unraveling phenotypic diversity in Cynodon spp. germplasm for forage accumulation and nutritive value in the transition zone

Abstract

AbstractCharacterizing phenotypic variation in germplasm collections is crucial for plant breeding. Cynodon spp. accessions maintained at the USDA National Plant Germplasm System (NPGS), and the core forage collection were screened in a replicated trial under two nitrogen rates (0 and 150 kg ha−1 per harvest) in Ardmore, OK. The goals for this study were to: (a) estimate genetic parameters for forage accumulation (FA) and nutritive value (NV), (b) estimate genotype × harvest (rgh) and genotype × environment (rge) interaction for all traits, (c) quantify FA and NV for commercial cultivars and selected accessions. The experiment was setup as a row‐column design with two replicates and augmented representation of controls: Tifton 85, Wrangler, Midland, and Cheyenne. The trial was harvested five times (twice in 2016 and three times in 2017) and data were analyzed using linear mixed models. Genetic parameters revealed the presence of significant phenotypic variation for FA and NV. Low genotype × harvest and genotype × environment interactions indicated genotypic stability and potential for selecting improved accessions for FA and NV. Several plant introductions (PIs) were identified for their improved FA and NV. The application of N increased FA and CP concentration in all harvests but did not significantly impact phenotypic variation in other NV traits. Phenotypic data will be deposited in the Germplasm Resource Information Network (GRIN)‐Global database.