Divergência genética e análise dialélica em pimenteiras ornamentais (Capsicum annuum L.)

• Ano de defesa: 2016
• Autor(a) principal: Pessoa, Angela Maria dos Santos
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Ciências Fundametais e Sociais; Programa de Pós-Graduação em Agronomia; UFPB
• Palavras-chave em Português: Capsicum annuum L.; Pimenteira; Variabilidade genética; Análise dialélica; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/14695

The genus Capsicum, belonging to the family Solanaceae, which comprises species of peppers and peppers. Among these, the main cultivated species are C. annuum L., C. frutescens L., C. chinense Jacq., C. baccatum L. and C. pubescens Ruiz and Pavon. Peppers of this genus are grown in various parts of the world, C. annuum being the most widely used. This species presents diversity for characteristics of size, flower and fruit, which gives it different potentialities of use, aimed at the consumption in natura, industrialization and for ornamental use. The great variability observed gives the potential species for use in breeding. Thus, the morphoagronomic characterization provides a series of information about genetic variability, which can be identified through genetic-statistical methodologies. The knowledge of the diversity between the individuals allows the arrangement of genotypes in groups, which when crossed, can obtain greater results of heterosis. The genotypes can be cross-linked and evaluated using the diallel analysis methodology, with those of Griffing (1956), Gardner and Eberhart (1966) and Hayman (1954) being the most used. In this way, the objective was to evaluate the genetic diversity between accessions of peppermint (C. annuum L.), and to perform diallel crosses between the divergent accesses to determine the promising crosses for ornamental purposes. The experiment was carried out in a greenhouse in the Plant Biotechnology sector of the Agricultural Sciences Center of the Federal University of Paraíba (CCA-UFPB). Sixteen accessions of peppermints (C. annuum L.) were used for morphoagronomic characterization based on 28 quantitative characters, referring to the seedlings, plant, flower and fruits. The design was a completely randomized design with 16 treatments with eight replicates. Data were submitted to analysis of variance, Scott-Knott averages test and estimated heritability. The genetic divergence was analyzed by the Tocher method, based on the generalized distance of Mahalanobis and analysis of canonical variables with graphic dispersion of the accessions. The relative importance of the variables was determined by the method described by Singh (1981) and by canonical variables. For the diallel analysis, 49 treatments (7 accessions and 42 hybrids) were used with eight ornamental peppercorns. The diallel analysis was performed to estimate the General Combination Capacity (CGC) and Specific Combination Capacity (CPC), according to the Griffing method (1956). To determine the heterosis and its components, the methodology of Gardner and Eberhart (1966) was used and to study the inheritance of the morphoagronomic characteristics, the methodology of Hayman (1954) was used. It was verified the existence of phenotypic divergence between the accessions of C. annuum L., and can be used in programs of genetic improvement of ornamental pepper. The accesses UFPB001, UFPB004, UFPB45, UFPB77.3, UFPB099, UFPB134, UFPB390 and Calypso were selected. The results showed that there was a predominance of the non - additive effects for the seedling characteristics and for the characteristics of plant, flower and fruits, there was influence of additive and non - additive effects, with superiority for the additive effects. The hybrids UFPB001xUFPB134, UFPB001xUFPB099, UFPB004xUFPB001, UFPB390xUFPB77.3 and UFPB77.3xUFPB099 can be used to continue the breeding program. There is diversity among the accesses studied, with significant effects of heterosis and its components. There are possibilities of genetic gains, through breeding programs, related to plant, flower and fruit characteristics in ornamental pepper cuts, and the UFPB001 and UFPB134 accessions presented the highest concentration of favorable alleles for size characters, UFPB001, UFPB004 and UFPB099 for Flowers and the UFPB390 and UFPB77.3 for fruit characters.