Método generalizado de análise de dialelos desbalanceados

Silva, Sílvia Agripina Gonçalves E; Morais, O. P. de; Rava, C. A.; Costa, J. G. C. da

doi:10.1590/s0100-204x2000001000011

Cited by 11 publications

(11 citation statements)

References 7 publications

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“…This indicates the existence of unidirectional dominance deviations (Silva et al 2000) and the negative manifestation of heterosis in the hybrid combinations, involving divergent ancestors (Table 3, main diagonal). Negative values of $ s ii were observed for the parents Bossier, Kent and Paraná, revealing positive heterosis in their hybrids, which in this case is disadvantageous, because it leads to increased disease symptoms.…”

Section: Resultsmentioning

confidence: 92%

Multivariate analysis of combining ability for soybean resistance to Cercospora sojina Hara

et al. 2004

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Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná and Uberaba), with different levels of resistance to Cercospora sojina, race 04, were crossed according to a diallel design, with no reciprocals, to determine the general and the specific combining abilities for the resistance. The evaluations of the reaction to the disease were performed 20 days after the inoculation of the fungus on the most infected leaflet of the plant, in the parents and in the F1 hybrids. To quantify the resistance, the following characteristics were evaluated: infection degree (ID); number of lesions per leaflet (NLL); lesion mean diameter (LMD); lesioned leaf area (LLA); percentage of lesioned leaf area (PLLA); number of lesions per square centimeter (NLC) and disease index (DI). The relative importance of each characteristic was evaluated by the canonical variables analysis and the LLA and NLL characteristics were eliminated from the multivariate function. With the remaining five characteristics, a multivariate index was created using the first canonical vector, which was submitted to the diallel analysis, according to Griffings fixed model, method 2. The most important characters to discriminate resistant from susceptible soybean plants to C. sojina were: ID, LMD, NLC, DI and PLLA. Cristalina, Davis and Uberaba cultivars are the best ones among those tested that can be recommended as parents in soybean breeding programs seeking resistance to Cercospora sojina. The additive, dominant and epistatic genetic effects were important for the expression of the resistance, although the additive genetic effect was the most important component.

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Section: Resultsmentioning

confidence: 92%

Multivariate analysis of combining ability for soybean resistance to Cercospora sojina Hara

et al. 2004

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“…The greater the absolute value of ii ŝ the greater is the effect of heterosis inherent to the cultivar, which has been manifested in all F 1 populations from this cross (Cruz & Regazzi, 2001 (Silva et al, 2000) and, consequently, of negative manifestation of heterosis in the hybrid combinations, involving divergent ancestors (Table 6). Negative values of ii ŝ were observed for Bossier, Kent and Paraná parents, revealing positive heterosis in their hybrids, which in this case is disadvantageous, because it leads to increased disease symptoms.…”

Section: Resultsmentioning

confidence: 98%

Diallel analysis for frogeye leaf spot resistance in soybean

Gravina

Sediyama

Filho

et al. 2003

Pesq. agropec. bras.

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-Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná and Uberaba), with different levels of resistance to Cercospora sojina, were crossed in a diallel design to determine the general (GCA) and specific (SCA) combining abilities relative to the inheritance of the resistance. Race 04 of the fungus was inoculated in the parents and in the 21 F 1 hybrids in a greenhouse in a completely randomized design, with 12 replications. The reactions to the disease were evaluated 20 days after the inoculation, always on the most infected leaflet. Both GCA and SCA were significant for all the evaluated characters, being inferred that, for the expression of the characters, the additive, dominant and, possibly, epistatic genic actions were important. The largest values of estimated SCA effect ) ŝ ( ij were observed in the hybrid combinations where at least one parent presented high GCA. Cristalina, Davis and Uberaba cultivars showed the largest estimates for GCA effect ( i ĝ ), and from the analysis of ii Ŝ , the contribution of these parents to heterosis of their hybrids will be towards the reduction of the disease symptoms. Therefore, these cultivars are indicated as parents in breeding programs that seek the development of soybean cultivars with resistance to frogeye leaf spot.Index terms: Glycine max, Cercospora sojina, combining ability, heterosis, genetic resistance, genetic parameters. Análise dialélica da resistência à mancha olho-de-rã em sojaResumo -Sete cultivares de soja (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná e Uberaba) com diferentes níveis de resistência à Cercospora sojina foram cruzadas de modo dialélico para avaliar as capacidades geral (CGC) e específica (CEC) de combinação quanto à herança da resistência. A raça 04 do fungo foi inoculada nos progenitores e nos híbridos F 1 , em casa de vegetação, num delineamento inteiramente casualizado, com 12 repetições. As avaliações da reação à doença foram feitas 20 dias após a inoculação, sempre no folíolo mais infectado. Ambas, CGC e CEC, foram significativas quanto a todos os caracteres avaliados, inferindo-se que, para a expressão dos caracteres, as ações gênicas aditivas, dominantes e, possivelmente, interações epistáticas foram importantes. Os maiores valores dos efeitos da CEC estimados ( ij ŝ ) foram observados nas combinações híbridas dos cruzamentos em que pelo menos um progenitor apresentou alta CGC. As cultivares Cristalina, Davis e Uberaba apresentaram as maiores estimativas do efeito de CGC ( i ĝ ) e, pela análise de ii Ŝ , a contribuição desses genitores para a heterose de seus híbridos será no sentido de redução dos sintomas da doença. Portanto, essas cultivares são indicadas como genitores em programas de melhoramento que visem à obtenção de cultivares de soja com resistência à mancha olho-de-rã.Termos para indexação: Glycine max, Cercospora sojina, capacidade combinatória, heterose, resistência genética, parâmetro genético.

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“…Rodrigues et al (1999) evaluated the inheritance of CBB resistance in the leaves and pods of snap and dry bean genotypes and only observed significant GCA effects for resistance in the leaves, while significant GCA and SCA effects were observed for Xap resistance in the pods. Silva et al (2000) evaluated the CBB responses of common bean genotypes in the leaves using an unbalanced diallel model and observed GCA values of high magnitude for Xap resistance. In most of the evaluated crosses, by means of the SCA effects, the partial dominance of the CBB susceptibility of bean plants was observed in the leaves.…”

Section: Resultsmentioning

confidence: 99%

<b>Combining ability for common bacterial blight resistance in snap and dry bean (<i>Phaseolus vulgaris</i> L.)

et al. 2014

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ABSTRACT. Common bacterial blight (CBB), which is caused by Xanthomonas axonopodis pv. phaseoli (Xap), is the main bacterial disease in snap beans and controlling this disease using resistant cultivars is still a challenge. This work aimed to study the combining ability for CBB resistance in Phaseolus vulgaris genotypes. Six parents (two genotypes of CBB-resistant dry bean and four susceptible snap bean accessions) were crossed in a complete diallel scheme without reciprocals to estimate the general and specific ability to Xap resistance. CBB resistance was evaluated by the inoculation with two Xap isolates, and its severity was evaluated based on the four following resistance components: area under the disease progress curve; scores in the leaves; latent period and diameter of pod lesion. Differences between the two isolates were observed considering all the disease components. Besides pathogen variability, significant GCA and SCA indicate that additive and non-additive effects are involved in Xap-resistance control for the evaluated genotypes, implying that CBC resistance is a trait with complex inheritance. For breeding purposes, the result demonstrates the need to apply breeding methods that are focused on advanced generations selection.Keywords: Xanthomonas axonopodis pv. phaseoli, disease-resistance inheritance, genetic effects, general and specific combining ability.Capacidade de combinação para resistência ao crestamento bacteriano em feijão comum e feijão-de-vagem (Phaseolus vulgaris L.)RESUMO. O Crestamento Bacteriano Comum (CBC), causado por Xanthomonas axonopodis pv. phaseoli (Xap) é a principal doença bacteriana na cultura do feijão-de-vagem e o controle a essa doença usando cultivares resistentes é ainda um desafio. Esse trabalho tem como objetivo estudar a capacidade a capacidade combinatória para a resistência ao CBC em genótipos de Phaseolus vulgaris. Seis genitores (dois genótipos resistentes de feijão comum ao CBC e quatro acessos suscetíveis de feijão-de-vagem) foram cruzados em um esquema de dialelo completo sem recíprocos para estimar a capacidade geral e específica de combinação para a resistência a Xap. A resistência ao CBC foi avaliada por meio da inoculação com dois isolados de Xap e a severidade avaliada a partir de quatro componentes de resistência: área abaixo da curva de progresso da doença, notas de severidade nas folhas, período latente e diâmetro da lesão em vagens. Diferenças entre os dois isoladas foram observados considerando todos os componentes da doença. Além da variabilidade dos patógenos, CGC e CEC foram significativas, indicando que os efeitos aditivos e não-aditivos estão envolvidos no controle da resistência a Xap para os genótipos avaliados, implicando que a resistência a CBC é uma característica com herança complexa. Para fins de melhoramento, os resultados demonstram a necessidade de aplicar métodos de melhoramento que são focados em seleção de gerações avançadas.Palavras-chave: Xanthomonas axonopodis pv. phaseoli, herança da resistência a doença, efeitos genéticos,...

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Método generalizado de análise de dialelos desbalanceados

Cited by 11 publications

References 7 publications

Multivariate analysis of combining ability for soybean resistance to Cercospora sojina Hara

Multivariate analysis of combining ability for soybean resistance to Cercospora sojina Hara

Diallel analysis for frogeye leaf spot resistance in soybean

<b>Combining ability for common bacterial blight resistance in snap and dry bean (<i>Phaseolus vulgaris</i> L.)

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