Successful wide hybridization and introgression breeding in a diverse set of common peppers (Capsicum annuum) using different cultivated ají (C. baccatum) accessions as donor parents

[EN] Capsicum baccatum, commonly known as aji, has been reported as a source of variation for many different traits to improve common pepper (C. annuum), one of the most important vegetables in the world. However, strong interspecific hybridization barriers exist between them. A comparative study of two wide hybridization approaches for introgressing C. baccatum genes into C. annuum was performed: i) genetic bridge (GB) using C. chinense and C. frutescens as bridge species; and, ii) direct cross between C. annuum and C. baccatum combined with in vitro embryo rescue (ER). A diverse and representative collection of 18 accessions from four cultivated species of Capsicum was used, including C. annuum (12), C. baccatum (3), C. chinense (2), and C. frutescens (1). More than 5000 crosses were made and over 1000 embryos were rescued in the present study. C. chinense performed as a good bridge species between C. annuum and C. baccatum, with the best results being obtained with the cross combination [C. baccatum (female) x C. chinense (male)] (female) x C. annuum (male), while C. frutescens gave poor results as bridge species due to strong prezygotic and postzygotic barriers. Virus-like-syndrome or dwarfism was observed in F-1 hybrids when both C. chinense and C. frutescens were used as female parents. Regarding the ER strategy, the best response was found in C. annuum (female) x C. baccatum (male) crosses. First backcrosses to C. annuum (BC(1)s) were obtained according to the crossing scheme [C. annuum (female) x C. baccatum (male)] (female) x C. annuum (male) using ER. Advantages and disadvantages of each strategy are discussed in relation to their application to breeding programmes. These results provide breeders with useful practical information for the regular utilization of the C. baccatum gene pool in C. annuum breeding.Juan P. Manzur thanks Universitat Politecnica de Valencia for a research predoctoral grant (2011-S2-4264, programa para la formacion de personal investigador). Authors are grateful to Centro Inv. Agr. Mabegondo, S. Larregla from NEIKER, P.W. Bosland from NMSU and the Consejos Reguladores of IGP Pimiento Asado del Bierzo, DOP Pimenton de Murcia, and IGP Piquillo de Lodosa for providing us with seeds from Arnoia, Guindilla de Ibarra, Numex, Bierzo, Bola and Piquillo, respectively.Manzur Poblete, JPA.; Fita, A.; Prohens Tomás, J.; Rodríguez Burruezo, A. (2015). Successful wide hybridization and introgression breeding in a diverse set of common peppers (Capsicum annuum) using different cultivated ají (C. baccatum) accessions as donor parents. PLoS ONE. 10(12). https://doi.org/10.1371/journal.pone.0144142Se0144142101

Avaliação do coeficiente de variação experimental para caracteres de frutos de pimenteiras

O objetivo deste estudo foi formular uma classificação para coeficientes de variação, de experimentos com pimentas do gênero Capsicum, para utilização em seis variáveis morfológicas do fruto. Foram selecionados 38 experimentos com resultados publicados, em que se constaram dados de caracterizações morfológicas do fruto e coeficientes de variação (CV) das seguintes variáveis respostas: peso médio do fruto, comprimento do fruto, comprimento do pedúnculo, maior e menor diâmetro do fruto e espessura do pericarpo. As faixas de classificação dos CV foram baseadas na metodologia proposta por Garcia (1989), que considera a propriedade da distribuição normal do CV. Pelo teste de Lilliefors, a 5% de probabilidade, todas as variáveis satisfizeram a pressuposição de distribuição normal do CV. As faixas de classificação do CV, obtidas para essas seis variáveis, foram distintas daquelas da classificação geral, proposta por Gomes (2000). Ademais, constatou-se que as classificações dos coeficientes de variação de variáveis morfológicas de pimenteiras do gênero Capsicum dependem da variável resposta, sendo que as maiores faixas de classificação de CV ocorreram para menor diâmetro do fruto, espessura do pericarpo e peso médio do fruto