Estimation of repeatability and genotypic superiority of elephant grass half-sib families for energy purposes using mixed models

Abstract

The mixed-model methodology is an alternative to select genotypes for traits highly influenced by the environment. In addition, this method allows FOR estimating the repeatability coefficient and predicting the number of assessments needed for a selection process to increase reliability. This study aimed to determine the minimum number of evaluations necessary for a reliable selection process and to estimate the variance components used for predicting genetic gains between and within half-sib families of elephant grass (Cenchrus purpureus (Schumach.) Morrone) using the mixed-model methodology. Half-sib families were generated using genotypes from the Active Germplasm Bank of Elephant Grass. The experiment was performed in a randomized block design with nine half-sib families, three replicates, and eight plants per plot. We evaluated 216 genotypes (individual plants) of elephant grass. The deviance analysis was carried out, genetic parameters were estimated, gains between and within families were predicted, and repeatability coefficients were obtained using Selegen software. There was genetic variability for selection within the families evaluated. The reliability values found above 60 % for plant height and number of tillers and above 80 % for dry matter yield suggest that only two evaluations are required to select superior genotypes with outstanding reliability. Sixteen genotypes were identified and selected for their productive potential, which can be used as parents in elephant grass breeding programs for bioenergy production.

Adaptability and stability via mixed models in elephantgrass (Cenchrus purpureus (Schumach.) Morrone) varieties for energy purposes

“…Over the course of the last 15 years, the Universidade Estadual do Norte Fluminense (UENF) has been dedicated to conducting studies aimed at obtaining, evaluating, selecting, and indicating high-quality genotypes of elephant grass, with a focus on its application in the field of bioenergy. Throughout this period, the results obtained have been encouraging in terms of the enhancement of this cultivation, as evidenced in studies carried out by Silva et al (2020), Gravina et al (2020), Vidal et al (2022), as well as Vidal et al (2023a) and Santana et al (2023). Simultaneously, the Empresa Brasileira Pesquisa Agro Pecuária (EMBRAPA) has played a significant role in the field of elephant grass studies, concentrating on the characterization and evaluation of germplasm, with an emphasis on biomass quality.…”

“…These selected individuals can contribute to the advancement of elephant grass breeding, specifically targeting the development of superior cultivars for the north and northwest regions of the state of Rio de Janeiro. Atroch et al (2013), Ambrósio et al (2021, Ambrósio et al (2023) and Vidal et al (2022;2023a) emphasized that stability, adaptability, and yield (HMRPGV) should be the primary criteria for selecting the best genotypes/ varieties/progenies. Therefore, characterizing elephant grass genotypes based on their patterns of adaptability and stability after the selection process for dry matter yield capacity is crucial for selecting genotypes to continue the breeding program.…”