Genetic control of soybean earliness and yield through the Hayman methodology

The understanding of the genetic control involved in characters of agronomic interest is of extreme importance to breeders aiming at planning procedures for breeding programs. Thus, the objective of this work was to study genetic aspects related to earliness and grain yield found in the initial generations of soybean, twice each year. The study evaluated six soybean parentes (MSOY6101, RSF6563IPRO, TMG123RR, SYN9078RR, TMG801 and MSOY9144RR) and their 15 F1´s in a greenhouse, during winter and summer. A second experiment conducted at Prof. Diogo Alves de Melo experimental field, located on the UFV campus, in Vicosa-MG, during the 2014/2015 agricultural year assessed parents and their segregating populations (F2). In all experiments, information were collected from individual plants. Results showed that both additive and dominance effects were important for the genetic control of soybean earliness and grain yield. Number of days to flowering and maturation and grain yield for the F1 and F2 generations, in winter and summer, is determined by dominant alleles. In regards to the studied characters, there was partial dominance mainly for the F1 generation and overdominance for the F2 generation. Parents MSOY6101 and RSF6563IPRO showed greater concentration of favorable alleles for flowering and maturation time reduction, and parents TMG123RR and SYN9078RR for grain yield. Parents TMG801 and MSOY9144RR gave the best contribution to cycle retardation for the F2 generation.