Reaction of common bean lines derived from recurrent selection for white mold resistance and aggressiveness of Sclerotinia sclerotirum isolates

Abstract

ABSTRACT:The objectives of this study were to verify the resistance of common bean lines derived from recurrent selection for white mold resistance and to identify those more stable to different isolates; to compare the aggressiveness of different Sclerotinia sclerotiorum isolates; and to verify isolates x lines interaction. Fifteen common bean lines were evaluated, twelve derived from recurrent selection for white mold resistance, one non-adapted source of resistance (Cornell 605), one moderately resistant and adapted (VC-16) and one susceptible to white mold (Corujinha). Ten isolates were used to inoculate the common bean lines through the straw test. A total of ten experiments were performed, one for each isolate. The randomized complete block design with three replications was used in each experiment. Each plot had five plants inoculated in two main branches, therefore the plot data was the average of the ten evaluations through a scale of nine grades. Diallel analysis were used to estimate the general reaction capacity (lines) and general aggressiveness capacity (isolates) to measure the resistance to white mold and the aggressiveness of the isolates, respectively. The GGE biplot analysis was used to group the common bean lines based on their resistance alleles and identify those more instable to the isolates. The resistance of the lines P4 and P10 was similar to Cornell 605, and they had stable reaction to different isolates and "Carioca" grain type. The lines of the advanced cycles of recurrent selection accumulated more favorable alleles than those of the first cycles, confirming the efficiency of the recurrent selection to increase white mold resistance in common bean. In addition, it was identified more aggressive isolates, UFLA 109 and UFLA 116, and a small magnitude of isolates x lines interaction, indicating a predominance of the horizontal resistance of the lines.

Research Article Diallel analysis for soybean resistance to the fungal pathogen <i>Sclerotinia</i> <i>sclerotiorum</i>

“…Thus, a need exists to develop cultivars with more stable resistance to this pathogen. The occurrence of both types of resistance has been reported for S. sclerotiorum on Phaseolus vulgaris (Silva et al, 2014;Leite et al, 2017). In those studies, SIC was significant, indicating the possible participation of vertical resistance in controlling the character.…”

“…Melo et al (1999) developed an efficient method that is able to provide information regarding the host's vertical and horizontal resistance and the aggressiveness of the pathogen isolates. This method has been used in several studies (Silva et al, 2014;Pereira et al, 2015;Valdo et al, 2016;Leite et al, 2017) but has not been investigated in the S. sclerotiorum-Glycine max pathosystem.…”

Combining abilities of soybean progenies and bradyrhizobium strains for biological nitrogen fixation

“…The strains SEMIA 587 and INPA 03-11B exhibited higher positive values of g j for most traits. The efficacy of diallel analysis has been proven in several studies related to disease resistance in plants (Leite et al, 2017;Valdo et al, 2016;Pereira et al, 2015;Silva et al, 2014). However, it has not yet been used to evaluate the relationship between soybean progenies and Bradyrhizobium strains.…”

Genetic parameters in intra-gene and inter-gene pool crosses of common bean (Phaseolus vulgaris L.) for root distribution

“…Recurrent selection cycles, together with the selection of the parents, seek to increase the frequencies of desirable alleles for quantitative traits, which results in phenotypic classes with superior performance for the speci c trait. Genetic gains have already been obtained for bean culture through recurrent selection for agronomic traits and resistance to diseases (Amaro et al 2007;Leite et al 2017).…”