Seleção de linhagens avançadas de amendoinzeiro (Arachis hypogaea L.) para as condições do semiárido brasileiro

Abstract

The cultivated peanut plant, one of the few tetraploid species in the genus Arachis, presents challenges for crossing with wild species, which are mostly diploid. However, the introgression of genes from wild species through breeding techniques has proven to be an effective strategy for expanding the genetic variability of the peanut crop. Several research institutions have been dedicated to crossing different peanut varieties, exploring the distinct characteristics that each species presents. Accurate estimation of genetic parameters is crucial as it allows understanding the extent of factors influencing the trait, as well as predicting the progress of selection in future generations. The peanut breeding team at Embrapa Cotton has focused on a population resulting from the cross between the wild peanut (A. batizocoi K9484 x A. duranensis SeSn 2848) 4x, named BatDur, which exhibits drought resistance characteristics, a recurring problem affecting many crops in the Brazilian semi-arid region, and the commercial cultivar BR1. This study selected advanced peanut lines based on the determination of genetic parameters, which have desirable agronomic characteristics adapted to the edaphoclimatic conditions of the semi-arid region. The experiment was conducted in the field at two distinct locations in Paraíba (Campina Grande and Alagoinha) from April to September 2023, using a randomized block design with nine treatments (one being BR1 and eight derived from the backcross between the BR1 cultivar and BatDur) and four replications. Seven agronomic traits were evaluated, such as: Main Stem Height (MSH); Number of Useful Pods (NUP); Weight of 100 Seeds (W100S); Harvest Index (HI); Pod Production (PODP); Seed Production (SEEDP) and Grain Yield (GY). The collected data were subjected to individual and combined analysis of variance, Scott-Knott mean clustering test, direct and indirect selection index, and the index proposed by Mulamba and Mock. The analysis revealed significant differences among genotypes for NUP, PODP, SEEDP, and HI, with the possibility of genetic gains. The lines RC 51 P4, RC 53 P4, and RC 78 P1 proved to be promising, with averages higher than BR1, indicating success in the selection process and meeting market demands. These lines are candidates for continuation in the peanut breeding program, as they present good productive characteristics under rainfed conditions, being promising for the semi-arid region.