Melhoramento de feijoeiro-comum com grãos pretos para resistência a murcha-de-fusário

• Autor(a) principal: Pereira, Débora Gonçalves
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/7163
• topic: Fusarium oxysporum; Phaseolus vulgaris; Fusarium oxysporum; Phaseolus vulgaris; GENETICA::GENETICA VEGETAL

The fusarium wilt, caused by the fungus Fusarium oxysporium f sp phaseoli, is considered one of the most important diseases affecting the common bean crop, especially in areas of intense and successive crops in the winter crop. There is little information about the variability of the pathogen and few common bean cultivars used in Brazil are resistant. The objectives of this study were to identify lines of common bean, previously characterized as resistant to fusarium wilt under controlled conditions, which combine resistance to fusarium wilt in the field and other favorable characters; obtain and select segregating populations of common bean with black beans resistant to fusarium wilt, with high grain yield and commercial grain size; select promising black bean lines with resistance to fusarium wilt, high grain yieldy and mass of 100 grains; estimate correlations and genetic and phenotypic parameters for these three characters. In the evaluation of the elite lines previously obtained as resistant to fusarium wilt, the tests were conducted in a randomized block design with three replications and plots consisting of four rows of four meters. Six lines were used, one carioca and five black beans, along with five cultivars in 28 experiments, between the years 2009 to 2011, in wet, winter and rainy growing seasons, at Paraná, Distrito Federal and Goiás States. In these trials were carried out evaluations for grain yield, plant architecture, lodging tolerance, reaction to fusarium wilt and reaction to anthracnose. Variance and mean grouping test analyzes were performed for the data obtained from five traits and analysis of adaptability and stability was realized for grain yield, using the method Nunes. For obtaining and selecting segregating populations under field conditions, the segregating populations were obtained from crosses in complete diallel scheme. Crosses were realized with eight lines with black granis and with different levels of resistance to fusarium wilt. The trials were composed by 28 populations obtained and two cultivars, one resistant and one susceptible to fusarium wilt. The populations obtained were evaluated in a randomized block design with three replications, in F2, F3 and F4, in winter/2012, winter/2013 and winter/2014, respectively. The three trials were conducted in Santo Antônio de Goiás in field infested by Fusarium oxysporum f. sp. phaseoli under irrigation by central pivot. The reaction to fusarium wilt, grain yield and weight of 100 grains were evaluated. Analyses were performed for individual and joint variance and for reaction to fusarium wilt was also carried out diallel analysis according Griffing (1956). Means were grouped using the Scott knot test. From the data obtained, two segregating populations were selected. 58 lines from each population were obtained, totalizing 116 lines which were evaluated with five controls. The evaluation of the lines was carried out in the winter/2015 in triple lattice design 11x11 with plots of two lines of 3 meters, also in Santo Antônio de Goiás - GO, in naturally infested area. There is variability in reaction to fusarium wilt, grain yield, plant architecture, lodging tolerance and reaction to anthracnose, among the lines evaluated. The genotype x environment interaction is important for the five characters evaluated. The five lines of black beans (CNFP 15867, CNFP 15870, CNFP 15869, CNFP 15868 and CNFP 15871) were resistant to fusarium wilt. Already CNFC 15872 line, with carioca grain, showed moderately susceptible. The CNFP 15867 and CNFP 15870 lines showed potential for use in breeding. BRS Esplendor cultivars and BRS Notavel are also good choices for planting in areas with fusarium wilt, with good agronomic performance. Regarding the evaluation of segregating populations was detected genetic variability for the three characters. The diallel analysis for reaction to wilt fusarium showed difference between the general combining ability (CGC) of parents and between the specific combination capacity (CEC) of the populations. The resistance to fusarium wilt was explained by additive and non-additive effects. The CNFP 15867 line showed positive estimate of CGC, been indicated for new crosses. Considering together, the mean of population for all traits and diallel analysis for reaction to fusarium wilt, populations BRS Esplendor x BRS Expedito and BRS Expedito x CNFP 15867 were selected. Considering the lines obtained from these two populations, the estimates of heritability, genetic variance and gain expected selection were high for the three traits, indicating good chance of successful selection. Considering the simultaneous selection, it was possible to obtain gains for the three traits, especially for reaction to fusarium wilt (31%). Eight lines have been identified that meet resistance to fusarium wilt, high grain yield and good grain size. There was a significant genetic correlation between fusarium wilt and grain yield, so lines resistant to fusarium wilt present high grain yield.