Selection of parents and segregating populations of carioca common bean resistant to Fusarium wilt

Fusarium wilt (Fusarium oxysporum f. sp. phaseoli) is one of the most common diseases in the common bean (Phaseolus vulgaris) crop, and the most viable alternative for its control is the use of resistant cultivars. However, the number of "carioca" cultivars, the most important commercial group in Brazil, which has a good level of resistance to this disease, is still low. To obtain populations with a higher degree of resistance, seven parents with different levels of resistance to Fusarium and which produce carioca grains were crossed in a complete diallel design. The 21 segregating populations obtained were evaluated in the years/generations 2012/F-3, 2013/F-4, and 2014/F-5 in experiments in Santo Antonio de Goias, GO, in the winter crop season (sowing in May), together with the check cultivars BRS Notavel (resistant) and BRS Cometa (susceptible) in an area naturally infested with Fusarium oxysporum f. sp. phaseoli, under a center pivot irrigation system. Reaction to Fusarium wilt, yield, and 100-seed weight were evaluated. Additive and non-additive effects contributed to control of reaction to Fusarium wilt, yield, and 100-seed weight. The statistically negative general combining ability ((g) over cap (i)) estimates for BRS Notavel (-0.51), CNFC 15872 (-0.20), IPR Juriti (-0.18), and BRSMG Talisma (-0.13) indicate that these parents are recommended for obtaining populations more resistant to Fusarium wilt. Among them, cultivar BRS Notavel also showed a statistically positive gi estimate for grain yield (87.90). Among the parents recommended for resistance to Fusarium wilt, cultivars IPR Juriti (0.99) and BRS Notavel (0.23) are those that most contributed to obtaining populations with larger-sized beans. Cultivar BRS Notavel is the most promising parent for participation in new crossing blocks, showing non-zero (g) over cap (i) estimates for all traits, favoring an increase in resistance to Fusarium wilt, yield, and 100-seed weight. Populations BRS Notavel / CNFC 15872, BRS Ametista / BRS Notavel, BRS Notavel / BRSMG Talisma, and BRS Ametista / BRSMG Talisma showed good mean values for reaction to Fusarium wilt, yield, and 100-seed weight and at least one parent with a good general combining ability estimate for resistance to Fusarium wilt. These four populations are promising for obtaining lines with superior performance for resistance to Fusarium wilt, yield, and larger-sized grains.