Desempenho de linhagens homozigotas de soja e ampliação de variabilidade genética por meio de hibridação artificial

Abstract

The demand for shorter-cycle soybean cultivars with high production potential has grown in recent years among farmers, especially in agricultural models that adopt both a crop and a second crop. The aim of this study was to advance homozygous soybean lines obtained through artificial hybridization and promote their adaptation to the specific environment of southwestern Paraná, with traits of precocity and productivity. The studies were conducted at UTFPR, Dois Vizinhos Campus. In Studies 1.1 and 1.2, eight soybean genotypes, five homozygous lines, and three commercial cultivars were evaluated for their grain productivity in the 2021/22, 2022/23, and 2023/24 crop seasons and in locations with lower and higher fertility. The design was randomized blocks, with three replicates. The data were subjected to analysis of variance and compared by Scott Knott. Dendrograms were prepared based on grain yield to verify the formation of similar groups. Adaptability and productive stability analyses were performed using the Wricke and Annichiarico methods. In Study 2, artificial hybridization was performed between commercial soybean lines and cultivars to expand genetic variability for the advancement of new segregating generations. This study was carried out in a greenhouse in the 2022/23 and 2023/24 crop seasons, with subsequent advancement of lines in the field. Line 1 stood out regarding its average productivity in the three crop seasons conducted in the same location, presenting a high genotypic confidence index. Line 4, in the area of lower fertility, and Lines 1 and 2, in the area of higher fertility, stood out regarding their average productivity, with values similar to or even better than the control cultivars, in the 2023/24 crop season. The 2021/22 crop season and the area with the lowest fertility in the 2023/24 crop season were considered unfavorable environments for soybean cultivation, the first due to the long period of water deficit and the second due to soil chemistry. The percentage of consolidated hybridizations was considered low due to the unsuitable conditions of the greenhouse regarding thermal amplitude and relative humidity.