Abstract
The objective of this study was to estimate genetic parameters for agronomic traits and nutritional value in intraspecific hybrids of B. decumbens. For this, a population of 1,415 hybrids was evaluated in field plots at Embrapa Beef Cattle in Campo Grande/MS/Brazil, with seven clippings in order to estimate field green weight (FGW); total dry matter (TDM); speed of regrowth (SR); tiller regrowth density (TRD); regrowth ability (REG); crude protein (CP); in vitro organic matter digestibility (IVD); neutral detergent fiber (NDF) and lignin (LIG). The statistical analyses were carried out using the mixed models methods. Genetic variability for all traits assessed was detected, and estimates of individual heritability were of medium to high magnitude, indicating the possibility of gains with selection. Significant genetic correlations were observed between FGW and TDM (0.99), TDM and SR (0.81), TDM and IVD (-0.71), TDM and LIG (0.71), and CP and IVD (0.70).
Key words:
Urochloa decumbens; signalgrass; recurrent selection; heritability
), genotype x clipping interaction variance (σ
), individual narrow sense heritability (h
), heritability based on progeny means (h
), accuracy (Acgem), repeatability coefficient of clipping means (rm
), genotypic correlation among clippings (rgmed), general mean (
) and range of B. decumbens progenies
2 test. + Evaluated in only one clipping in the dry season. # Ratio of the difference between the maximum and minimum predicted genotypic value (BLUP) in relation to the general mean, expressed as percentage: [(BLUP max - BLUP min)/(BLUP average)] x 100.