Selection of squash “Menina Brasileira” carrying the allele “Bush” with high yield potential

• Published in: Horticultura brasileira 2019-03, Vol.37 (1), p.35-39
• Main Authors: Ferreira, Mariane G, Almeida, Gabriella Q de, Pessoa, Herika P, Dariva, Françoise D, Dias, Felipe de O, Nick, Carlos
• Format: Magazinearticle
• Language: English
• ISSN: 0102-0536; 1806-9991
• DOI: 10.1590/s0102-053620190105

ABSTRACT This study was performed to introduce the allele Bush of commercial cultivars with a bush growth habit into Cucurbita moschata accessions and select the best crossings for production potential and standard fruit shape “Menina Brasileira” through general combining ability (GCA) and specific combining ability (SCA). To determine GCA and SCA, a partial diallel analysis was performed. The parental group (group I) consisted of two cultivars containing the dwarfism bush gene, and the second group (Group II), formed by five accessions of UFV Vegetable Germplasm Bank, with high production potential and fruit shape “Menina Brasileira”. We evaluated: productivity (PROD), fruit shape (FORM), growth rate until the 50th day after transplanting (CRESC), and length of the main stem on the 50th day (COMP). Significant differences were noticed for CRESC and COMP only between GCA of parents belonging to group I, in which Zapallo stood out. For PROD and FORM, diallel analysis proved to be efficient in studying GCA effects. Cultivar Piramoita (group I) and accessions BGH-4360 and BGH-5253 (group II) showed positive values for GCA, suggesting that these parents possess a higher frequency of favorable alleles for these two traits. Significance in SCA effects was also verified, highlighting the crossing Piramoita x BGH-4360, for PROD, indicating that this combination is the most promising for breeding purposes. RESUMO Objetivou-se introduzir o alelo Bush, de cultivares com hábito de crescimento tipo “moita”, em acessos de Cucurbita moschata e selecionar os melhores cruzamentos quanto ao potencial produtivo e ao formato de fruto padrão “menina brasileira” por meio da capacidade geral (CGC) e da capacidade específica (CEC) de combinação. Para determinar a CGC e a CEC foi realizada análise dialélica parcial. O grupo parental (grupo I) foi formado por duas cultivares tipo “moita”, enquanto o segundo grupo (grupo II) por cinco acessos do Banco de Germoplasma de Hortaliças da UFV, com alto potencial produtivo e formato de fruto “menina brasileira”. Foram avaliadas a produtividade (PROD), o formato de fruto (FORM), a taxa de crescimento até os 50 dias (CRESC) e o comprimento da rama principal aos 50 dias (COMP). Para CRESC e COMP, houve diferenças significativas apenas entre a CGC dos genitores do grupo I, onde destacou-se a cultivar Zapallo. Para as características PROD e FORM a análise dialélica mostrou-se eficiente no estudo dos efeitos de CGC. A cultivar Piramoita (grupo I