Variância genética de açúcares redutores e matéria seca e suas correlações com características agronômicas em batata

Abstract

RESUMO -O objetivo deste trabalho foi estimar os componentes de variância e herdabilidade relativos ao teor de açúcares redutores e à matéria seca, e suas correlações com algumas características agronômi-cas em batata (Solanum tuberosum L.). Foram utilizados quarenta clones de batata escolhidos aleatoriamente do Programa de Melhoramento Genético da Embrapa-Centro de Pesquisa Agropecuária de Clima Temperado. Os experimentos de campo foram conduzidos no outono e na primavera de 1996, em Pelotas, RS. Os teores de açúcares redutores e de matéria seca foram analisados após o armazenamento dos tubérculos em câmara fria (5±1ºC). As variâncias genéticas relativas a açúcares redutores e a matéria seca foram moderadas, e as variâncias dos erros, altas, proporcionando valores de herdabilidade relativamente baixos. O teor de açúcares redutores foi positivamente correlacionado com a maioria das características agronômicas, e negativamente correlacionado com o teor de matéria seca. As correlações entre a matéria seca e as características agronômicas foram baixas e não-significativas.Termos para indexação: Solanum tuberosum, herdabilidade, processamento, genética quantitativa. VARIANCE OF GENETIC REDUCING SUGARS AND DRY MATTER AND THEIR CORRELATIONS WITH AGRONOMIC TRAITS IN POTATOESABSTRACT -The objective of this research was to estimate the components of the variance and heritability relating to reducing sugars content and to dry matter, and their correlations with some agronomic traits of potato (Solanum tuberosum L.). Forty potato clones randomly chosen by the Embrapa-Centro de Pesquisa Agropecuária de Clima Temperado Breeding Program were used. The field experiments were carried out in the fall and in the spring of 1996, in Pelotas, RS, Brazil. Sugar and dry matter content were analyzed after storing tubers in cold chamber (5±1ºC). Genetic variances relating to reducing sugars and to dry matter content were moderate, and error variances were high, providing relatively low heritability values for both traits. The reducing sugar content was positively and significantly correlated with most of the agronomic traits and negatively correlated with dry matter content. The correlations between dry matter and agronomic traits were low and not significant.

Technological quality and utilization of potato tubers

“…The specific gravity variable showed a positive correlation with starch content (r = 0.51; P < 0.05), and a negative correlation with reducing sugars contents (r = -0.58; P < 0.05) (Table 3), confirming results by Salamoni et al (2000) and Gould (1988). It is also interesting to point out that specific gravity showed a positive correlation with texture (r = 0.82; P < 0.01), pH (r = 0.55; P < 0.05), and soluble solids (r = 0.44; P < 0.10).…”

“…Thus, specific gravity can indirectly provide a dry matter content estimate, and is also reated to industrial yield, oil absorption during frying, and final product quality. Specific gravity studies have revealed that a positive correlation exists with dry matter content (Schippers, 1976), and a negative correlation exists with reducing sugars content (Iritani & Weller, 1974;Salamoni et al, 2000).…”

Performance of advanced potato clones: plant vigor, tuber yield and specific gravity

“…This is probably due to the longer time necessary to perform photosynthesis and provide higher yield (Silva et al, 2012), which occurs until the end of the plant cycle (Pohl et al, 2009). In another study Salamoni et al (2000) did not verify correlation between plant vigor and sugar content and dry matter content in potato tubers, agreeing with the present work regarding the specific gravity.…”

Heritability and correlation among potato tuber traits

“…For reducing sugar content, the heritabilities varied from 0.32 (Salamoni et al 2000) to 0.51 in spring and 0.73 in autumn (Chalá et al 2001). For dry matter content, the heritabilities varied from 0.38 (Salamoni et al 2000) to 0.72 (Rodrigues and Pereira 2003). Heritability estimates of 0.49 and 0.87 were found respectively for chip color and tuber number (Rodrigues and Pereira 2003).…”

“…However, we found different heritability estimations for other tuber traits. For reducing sugar content, the heritabilities varied from 0.32 (Salamoni et al 2000) to 0.51 in spring and 0.73 in autumn (Chalá et al 2001). For dry matter content, the heritabilities varied from 0.38 (Salamoni et al 2000) to 0.72 (Rodrigues and Pereira 2003).…”