Qualidade tecnológica de grãos de genótipos de feijoeiro cultivados em diferentes ambientes

Abstract

RESUMONo procedimento de registro e muitas vezes de proteção de novo cultivar de feijão, certas exigên-cias de mercado têm de ser atendidas e, entre elas, tão importantes quanto à produtividade e à resistência a doenças, está a qualidade tecnológica do produto (grão) comercializado, que vai chegar ao consumidor final. Desse modo, em um programa de melhoramento, visando ao processo de aceitação do novo cultivar no comércio, deve-se observar a importância da seleção de genótipos que apresentem tanto o tempo de cocção reduzido, com tegumentos que não se partam durante o cozimento, como também a alta expansão volumétrica após o cozimento. O objetivo deste trabalho foi avaliar a qualidade tecnológica de dezenove genótipos de feijoeiro que compuseram os experimentos regionais (7 locais; 12 experimentos) para determinar o Valor de Cultivo e Uso (VCU), nas épocas da seca, de inverno e das águas em 2000, no Estado de São Paulo, bem como as diferenças entre os genótipos e as correlações existentes nos caracteres avaliados. As avaliações revelaram que as condições locais de obtenção dos grãos para análi-se de qualidade tecnológica influenciam nos resultados e na diferenciação entre os genótipos, indicando alta interação Genótipo x Ambiente. Também reportaram que os genótipos FT-Porto Real, IAPAR-80, PF902998, FT901909 e o GenC97-10 foram superiores aos padrões correspondentes quanto ao tempo de cocção. O uso de seleção precoce com base em correlações fenotípicas existentes entre os caracteres não é expressiva devido a sua baixa/média magnitude.Palavras-chave: feijão, tempo de cocção, variabilidade, expansão volumétrica, embebição em água. ABSTRACT COOKING QUALITY PARAMETERS OF COMMON BEAN GENOTYPES, SOWN IN DIFFERENT SEASONS AND LOCATIONSDuring the process of cultivar releasing and registration, several marketing requeriments, as important as yelding potential and disease resistance , should be taken into account in a bean breading program. These are related to the grain cooking quality and can determine the level of acceptance by the final consumer: a) reduced cooking time; b) stability of grain tegument during cooking; c) high volume expansion after cooking, and so on. The main aims of this research work has been to evaluate cooking quality of nineteen common bean genotypes, sown in seven experimental sites and three different growing seasons (summer, winter and dry periods) in the State of São Paulo, Brazil, as well as the possible correlation with agronomic characters. High and significant genotype x environment interactions have been detected as to cooking quality characters but correlation with agronomic characters ware of low values. Genotypes FT-Porto Real, IAPAR-80, PF 902998, FT 901909 and Gen C 97-10 have revealed statistically shorter cooking times as compared to control checks.

Technological quality of common bean grains obtained in different growing seasons

“…Various studies indicate an inverse association between cooking time and water absorption (Dalla Corte et al, 2003;Rodrigues et al, 2005a). Nevertheless, the genotype with the highest water absorption capacity will not necessarily have the shortest cooking time, as already reported by Carbonell et al (2003) and Durigan et al (1978).…”

“…Values of water absoption capacity before cooking (Peanc) and after cooking (Peapc), cooking time (CT), percentage of whole grains after cooking (PWG), volumetric expansion before cooking (EXPVbc) and after cooking (EXPVac), dry/raw grain density (DD), grain density after soaking (SD) and grain density after cooking (CD) and total soluble solids in the broth (TSSb) assess the behavior of common bean genotypes in regard to the cooking time of beans produced in different seasons showed that the common bean grains produced in the 2005 rainy crop season had a greater mean cooking time than those produced in the 2005 and 2006 dry crop seasons. This fact may be explained by the possibility of interference of environmental conditions in the physiological quality and in change in the integrity of the seed coat, with consequent changes in regard to water absorption capacity and cooking time (Carbonell et al, 2003;Dalla Corte et al, 2003;Kigel, 1999;Lemos et al, 2004). The percentage of whole grains after cooking is another relevant characteristic to consider in the common bean industrialization process because genotypes are sought that exhibit low cooking time and a high percentage of whole grains.…”

“…Considering the scale of Proctor and Watts (1987), in identifying the level of resistance of the grains to cooking, it was observed that the values obtained in the combination of the three growing seasons in relation to cooking time fit within the definition of normal resistance (21 to 29 minutes) to beans resistant to cooking (33 to 36 minutes). This variation is due to the genetic differences present in the genotypes, environmental influence and genotype by environment interaction (Carbonell et al, 2003;Dalla Corte et al, 2003). The genotypes C2-1-6-1, C4-8-1-1, LP04-03, IAC-Imperador, P5-4-4-1 and Pr11-6-4-1-2 stood out, with cooking times less than that of the control IAC-Alvorada (30.21 minutes) ( Table 4).…”

“…For Resende and Corrêa (2007), the volumetric expansion rate expresses water diffusion within the grains and, according to Carbonell et al (2003), volumetric expansion is a desirable characteristic which has an influence on acceptability of a new cultivar, which should have high grain expansion after cooking. Considering that water diffusion in the grain may be negatively affected by the degree of lignification of the grain (Teixeira et al, 2005), the results of this characteristic may be an indication of lower lignin content in the grains of genotype Pr14-2-3-2.…”

“…Various authors have reported the existence of the genotype and environment interaction for this characteristic, with differences being observed in behavior of lines and cultivars in different locations, crop years and planting times (Carbonell et al, 2003;Ribeiro et al, 2007;Rodrigues et al, 2004;2005b). Bordin et al (2010) Therefore, the aim of this study was to assess the effect of different periods of the growing season on the technological quality of common bean grains.…”