Variação de caracteres em híbridos de abacaxizeiro obtidos de diferentes cruzamentos

Abstract

, RANULFO CORRÊA CALDAS 2 , DAVI THEODORO JUNGHANS 2 RESUMO -A herança dos caracteres utilizados na seleção de híbridos de abacaxi é de suma importância para o sucesso dos programas de melhoramento genético desta fruteira. O trabalho teve como objetivo analisar as variações observadas nos principais caracteres utilizados na seleção de híbridos de abacaxi obtidos de diferentes cruzamentos. Foi realizada a análise de variância dos caracteres: altura da planta do solo até à base do fruto, comprimento do pedúnculo, peso do fruto sem coroa, peso da coroa, teor de sólidos solúveis e acidez titulável de 446 genótipos avaliados e 213 selecionados. Observou-se uma diminuição do peso do fruto nos híbridos selecionados na maioria dos cruzamentos e aumento dos sólidos solúveis em todos os cruzamentos, quando comparados com todos os genótipos avaliados. Constatou-se correlação linear simples positiva signifi cativa entre o peso do fruto e a altura da planta. Foi observada também correlação linear simples signifi cativa, de baixa magnitude, positiva entre o peso do fruto e o peso da coroa, a altura da planta e o peso da coroa, a altura da planta e o teor de sólidos solúveis e negativa entre o teor de sólidos solúveis e o comprimento do pedúnculo. Verifi cou-se diferença entre os cruzamentos na seleção de genótipos de abacaxi para os caracteres estudados. Termos para indexação: Ananas comosus var. comosus, hibridação, agrupamento. CHARACTERS VARIATION IN PINEAPPLE HYBRIDS OBTAINED BY DIFFERENT CROSSESABSTRACT-The inheritance of traits used for the selection of pineapple hybrids is very important for the success of the genetic breeding program of this fruit crop. The objective of the present work was to analyze the variations observed in main traits used for the selection of pineapple hybrids obtained by different crosses. The analysis of variance for 446 evaluated and 213 selected genotypes was carried out for the following traits: plant height from soil to the base of the fruit, peduncle length, weight of the fruit without the crown, weight of the crown, total soluble solids content and titrable acidity. In general, it was observed that fruit weight decreased for the selected hybrids in most crosses and the total soluble solids content increased in all crosses. Positive and signifi cant simple linear correlation was observed between fruit weight and plant height. Also a positive signifi cant simple linear correlation was observed between fruit weight and crown weight, however with lower magnitude, plant height and crown weight, plant height and total soluble solids content, and negative, between total soluble solids content and peduncle length. The difference between the crosses in the selection of pineapple genotypes for the traits studied was verifi ed.

Selection of pineapple hybrids via genotypic values (REML/BLUP) for fruit mass and total soluble solids

“…The remaining hybrids non-selected within both groups were eliminated, because they presented genotypic values of FMWC <1.60 kg and TSS <15.90 ºBrix. [5], analyzing phenotypic values observed a decrease in fruit weight from selected genotypes in most of the crossings and an increase of total soluble solids in all crossings, in relation to own parents. This result was attributed to the fact that only individuals with fruit weight between 0.9 kg -2.5 kg and total soluble solids higher than 13 °Brix were selected, occurring discard of all genotypes with more than 2.5 kg.…”

“…Possibility of to pre-select cloned hybrids with higher genotypic values, in relation to overall averages, was evidenced by the higher proportions of estimated genotypic variances for both traits (FMWC and TSS) (Table 5). These evaluated hybrids are descendants of 'Pérola', 'MD-2', 'BRS Imperial' and 'BRS Vitória' that have a high variation to the various traits on related to plant and fruit [5,3]. Cabral et al [16] highlighted this segregation for traits of agronomic importance is due to the majority of heterozygous loci of cultivars used as direct hybridization parents.…”

“…Usually, the highest prices are paid for larger fruits with a mass greater than 1.5 kg and total soluble solids of 14-16 °Brix [2,3]. Just as reported by Cabral et al [4] and Cabral et al [5] to many important traits for the genetic breeding of pineapples in Brazil, the selection was performed from minimum values defined for fruit mass without crown (FMWC) and total soluble solids (TSS). The pineapple growing in Brazil is still based on 'Pérola' cultivar, that although susceptible to fusariosis and totally spiny leaf margin, presents wide adaptation, vigorous plant growth, excellent fruit quality for fresh national market and average weight of 1.6 kg [2,3].…”

Caracterización morfoagronómica de genotipos de piña (Ananas spp.) en un suelo de terraza alta de Villavicencio

“…Sin embargo, como es difícil encontrar una variedad que reúna todas las características ideales, es conveniente escoger variedades para usos específicos según las demandas de los consumidores y con adaptación específica a las regiones de siembra. Con relación a la longitud del pedúnculo, un buen cultivar de piña debe presentar valores menores de 20 cm, para evitar la caída de frutos y el golpe de sol (Cabral et al, 2009). En el presente trabajo, el híbrido MD-2 presentó los datos de pedúnculo más corto con 21.1 cm, diferente significativamente de los otros tres cultivares evaluados para características de frutos, además de su mayor contenido de azúcar de 17.5 grados Brix (Tabla 5).…”

“…En Brasil, las normas de clasificación de piña consideran que el peso del fruto comercial debe estar entre 900 y 2400 g, el contenido de azúcares debe ser superior de 12º Brix. Para la industrialización de la piña, el contenido de azúcares debe estar entre 14 y 16º Brix, y la acidez total entre 0.65 y 0.95 (Cabral et al, 2009). Esto indica que los cuatro genotipos evaluados para características de fruto, cumplen todos el requisito de grados Brix para consumo en fresco, pero para industrialización, el cultivar nativo Mitú se mostró ligeramente abajo con 13.7 (Tabla 5).…”