Genetic control of characters associated with bean golden mosaic geminivirus resistance in Phaseolus vulgaris L.

Abstract

Bean golden mosaic is the most important viral disease of the bean crop (Phaseolus vulgaris L.) in Latin America. The genetics of resistance to a Brazilian strain of bean golden mosaic virus (BGMV), was studied in a 4 x 4 diallel cross without reciprocals, among the parental genotypes DOR 303, EMGOPA 201 Ouro, Carnaval, and Redlands Greenleaf C. Seedlings of the four parents, six F1 hybrids, 12 backcrosses, and F2 generations for each combination were inoculated on the eighth day after sowing by exposure to a viruliferous whitefly (Bemisia tabaci Genn.) population for 24 h, in a glasshouse, prior to transplantation to field conditions. The full set of two parents, F1, F2 and respective backcrosses for each combination was considered to be a family. Data were recorded and analyzed for foliar yellowing, plant dwarfing, and pod malformation, using a randomized block design, with two replications. Weighted generation mean analysis was performed for each of the six families. An additive gene action model was significant for the three characteristics evaluated. On the other hand, non-additive gene action had greater absolute value in most cases. Resistance to foliar yellowing conferred by genes from DRO 303 was highly heritable and was expressed equally well in the different genetic backgrounds evaluated. Such resistance may be oligogenic. Broad- and narrow-sense heritabilities were relatively high for all response traits. The three traits studied were all positively correlated, indicating that they can be simultaneously selected for enhancement. The highest correlation coefficient was obtained for dwarfing x pod malformation.<br>O mosaico dourado é a principal doença virótica da cultura do feijoeiro (Phaseolus vulgaris L.) na América Latina. A genética da resistência ao vírus do mosaico dourado do feijoeiro (BGMV), isolado do Brasil, foi conduzida em um dialelo 4 x 4 sem os recíprocos, entre os parentais DOR 303, EMGOPA 201 Ouro, Carnaval e Redlands Greenleaf C. Plântulas com oito dias de idade, dos pais, híbridos F1, retrocruzamentos e geração F2, foram inoculadas através da exposição a uma população virulífera de moscas brancas (Bemisia tabaci Genn.) por 24 h, antes do transplantio para condição de campo. O grupo completo de dois parentais, F1, F2 e respectivos retrocruzamentos foi considerado uma família. Foram coletados e analisados os dados de amarelecimento foliar, nanismo e de deformação de vagens, usando o delineamento experimental de blocos ao acaso com três repetições. Análise ponderada de médias de gerações foi executada para cada uma das seis famílias. Foram detectados efeitos gênicos aditivos significantes controlando todos os caracteres avaliados. Por outro lado, na maioria dos casos, houve predominância da ação gênica não aditiva. A resistência ao amarelecimento foliar, conferida por genes de DOR 303, foi altamente herdável e se expressou igualmente bem nos diferentes 'backgrounds' genéticos avaliados. Ela pode ser oligogênica. Estimativas das herdabilidades no sentido amplo e restrito foram relativamen...

Inheritance of root traits and phosphorus uptake in common bean (Phaseolus vulgaris L.) under limited soil phosphorus supply

“…This indicates that the additive portion of the heritable variation predominates in the inheritance of root traits in common bean. Additionally, the presence of additive × additive effects, particularly in the second experiment, indicates the possibility of transgressive segregants in later selfed generations (Pessoni et al, 1997), and confirms a polygenic system of inheritance for root traits in common bean (Fawole et al, 1982b).…”

“…The phenotypic, genotypic and environmental correlations were calculated using the phenotypic, genotypic and environmental variances and covariances of the characters. The phenotypic covariances were estimated between pairs of characters in the F2, the environmental covariances between pairs of characters in the parental and F1 generations, and the genotypic covariance by the difference between phenotypic and environmental covariances; the phenotypic, genotypic and environmental variances of X and Y were calculated in a similar fashion (Pessoni et al, 1997). The efficiency of indirect selection was estimated by ρ = r G (h 2 Y / h 2 X ) 1/2 , where ρ is the indirect response on the alternate trait Y by the direct selection on a primary trait X, r G is the genotypic correlation between X and Y, and h 2 X and h 2 Y are the heritabilities of traits X and Y (Scully et al, 1991;Cruz & Regazzi, 1997).…”

Backcross assisted by microsatellite markers in common bean

“…Regarding the genetic control of the resistance to BGMV, there is no consensus within the scientific community, with information existing in the literature suggesting that the resistance to BGMV is under polygenic control (Pessoni et al, 1997), monogenic control and oligogenic control Melo et al, 2005).…”

Combining ability as a strategy for selecting common bean parents and populations resistant to white mold

“…These authors found that WM resistance showed quantitative inheritance mainly governed by genes with additive effect. Pessoni et al (1997) also used intergroup diallel crosses to study genetic control of common bean reaction to BGMV, in which each group was composed of four parents, without reciprocal crosses. These authors observed high heritability in a broad and restricted sense, concluding that inheritance of resistance to BGMV in the common bean populations is oligogenic.…”

“…Many methods are used in analysis of diallel crosses, such as methods proposed by Yates (1947), Hayman (1954), Griffing (1956), Kempthorne (1956), Kempthorne and Curnow (1961), Gardner and Eberhart (1966), Miranda Filho and Geraldi (1984), and Oliveira et al (1987). The application of diallel crosses and analysis of combining ability as an approach for parent selection and understanding genetic control has been used in common bean for important agronomic traits, such as resistance to WM (Fuller et al 1984), golden mosaic (Bean golden mosaic virus -BGMV) (Pessoni et al 1997), common bacterial blight [Xanthomonas axonopodis pv. phaseoli (Smith) and X. fuscans subs.…”