Pesquisa Agropecuária Brasileira (2012) 47, 948-954

Jefté Ferreira da Silva, Cândida Hermínia Campos de Magalhães Bertini, Ervino Bleicher and João Gutemberg Leite Moraes (2012)
Divergência genética de genótipos de feijão-de-corda quanto à resistência ao pulgão-preto
[Genetic divergence of cowpea genotypes for resistance to black aphid]
Pesquisa Agropecuária Brasileira 47 (7), 948-954
Abstract: The objective of this work was to evaluate the genetic divergence among cowpea genotypes as to resistance to black aphid (Aphis craccivora), and to identify the best combinations between resistant genotypes. The experimental design was a randomized complete blocks with 51 treatments, represented by genotypes, and four replicates. Plants were infested 15 days after sowing, with five female adults. The number of adults and nymphs, at two and four days after infestation, respectively, and the relationship between them were evaluated. Mulamba and Mock's sum of ranks index, Mahalanobis' generalized distances, and Tocher's optimization method were used to assess the genetic distance among genotypes. The largest differences were observed between the genotypes BRS Guariba and Sete Semanas, and between TVu 410 and Sete Semanas, whereas BRS Guariba and TVu 410 were the most similar. The genotypes BRS Guariba, TVu 410, BRS Paraguaçu, TVu 36, Sempre Verde, TVu 408 P₂, Setentão, and Epace 10 show resistance to black aphid. Crossings between Setentão and BRS Guariba, TVu 410, BRS Paraguaçu, TVu 36, TVu 408 P₂, and between Epace 10 and Sempre Verde, BRS Guariba and TVu 410 are promising for new genetic combinations in breeding programs to improve resistance to black aphid.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis craccivora	Cowpea and relatives (Vigna)	Brazil (south)