Pollen mixture, a recombination alternative in common bean breeding

Abstract

Recombination can be a limiting factor in recurrent selection programs, especially in species such ascommon bean where artificial hybridization reduces seed setting. Therefore, the development of new techniquesto improve recombination efficiency is important. Experiments were conducted in two sowing periods, July(autumn-winter season) and February (dry growing season), using the ESAL 686 and Small White cultivars asthe female parents and the Carioca, Ouro Negro and ESAL 686 or Small White cultivars as male parents,depending on the female parent. Five technicians with different hybridization experience and two hybridizationmethods (with and without emasculation) were tested. A mixture of pollen from the three male parents was usedin the pollinations, which were made in greenhouse. The resulting F1 seeds were sown in the field and the maleparent identified by morphological markers. The greatest pollination success (68%) occurred in the autumn-winter season without emasculation. It was also observed that the technicians differed in efficiency, but nomethod x technician interaction was detected. The pollen mixture was efficient to improve recombination.