Effect of Calcium Deficiency on Melon (Cucumis melo L.) Texture and Glassiness Incidence During Ripening

Abstract

The effects of calcium deficiency on the appearance of ''glassiness'' or ''watercore'' and texture evolution in cantaloupe muskmelon (Cucumis melo L.) and on polygalacturonase (PG) and b-galactosidase activities and their relation to ethylene production were studied. Watercore increased in melons cultivated with calcium-deficient nutrient solutions, as did ripening, which could be related to their lower calcium content. Whole fruit firmness and flesh firmness decreased from 34 days after set (DAS) in control melons, while in calcium-deficient fruits, the softening process had begun before day 33 after fruit set, both parameters being significantly lower in these. The activity of b-galactosidase increased during melon ripening, reaching maximum values two days earlier in melons grown with calcium-deficient solutions than in control ones. However, no PG activity was detected in control melons, but this activity increased during ripening in melons grown with low and removed calcium solutions, a fact that positively correlated with decreased fruit firmness. Ethylene production rate increased sharply as fruit ripened, which could be responsible for the increase in b-galactosidase activity and so for fruit softening. However, the higher softening and glassiness incidence observed in melons irrigated with calcium-deficient solutions could be due to PG activity.Se ha estudiado el efecto de la deficiencia de calcio en la aparicio´n de vitrescencia y en la evolucio´n de la firmeza en melo´n Cantalupe (Cucumis melo L.), ası´como en la actividad de los enzimas poligalacturonasa (PG) y b-galactosidasa y su relacio´n con la produccio´n de etileno. La aparicio´n de vitrescencia aumentod urante la maduracio´n en todos los melones cultivados con disoluciones nutritivas deficientes en calcio, lo que podrı´a relacionarse con su menor contenido en calcio. La firmeza del fruto entero y de la pulpa disminuyo´a partir de los 34 dı´as desde el cuaje (DAS) en los melones control, mientras que en los frutos deficientes en calcio, el proceso de ablandamiento habı´a comenzado antes de los 33 DAS, siendo ambos para´metros significativamente ma´s bajos en estos frutos. La actividad b-galactosidasa aumento´durante la maduracio´n del melo´n, alcanzando valores ma´ximos dos dı´as antes en los melones cultivados con disoluciones deficientes en calcio que en los controles. No se detecto´actividad PG en los melones control, sin embargo esta actividad aumento´durante la maduracio´n en los melones cultivados con disoluciones deficientes en calcio, lo que se correlaciono´positivamente con el ablandamiento de los frutos. La tasa de produccio´n de etileno aumento´ra´pidamente con la maduracio´n, lo que pudo ser responsable del aumento en la actividad b-galactosidasa y del ablandamiento del fruto. Sin embargo, la incidencia de vitrescencia y el mayor ablandamiento de los melones cultivados con disoluciones deficientes en calcio podrı´a deberse a la actividad poligalacturonasa.

Effect of phosphogypsum application on the chemical properties of Andosols, and the growth and Ca uptake of melon seedlings

“…Aside from high content, Ca nutrients play an important role in the growth and fruit quality of melons. Calcium deficiency causes rapid fermentation of the fruit under forced culture conditions, an incidence of glassiness and reduces fruit hardness (Serrano et al. 2002).…”

“…Aside from high content, Ca nutrients play an important role in the growth and fruit quality of melons. Calcium deficiency causes rapid fermentation of the fruit under forced culture conditions, an incidence of glassiness and reduces fruit hardness (Serrano et al 2002). In addition, Ca deficiency reduces root development in melon (Fujimoto 2000), indicating that Ca possibly facilitates good rearing of seedlings through root development.…”

Calcium Fertigation Ineffective at Increasing Fruit Yield and Quality of Muskmelon and Honeydew Melons in California

“…Domestic use of California melons in ''fresh cut'' processing is increasing, and fruit firmness is also critical for that use. Premature softening and ''glassiness'' of melons (a physiological disorder in which fruit flesh appears water-soaked) have been associated with low calcium concentration in the fruit tissue (Lester andGrusak, 1999, 2001;Madrid et al, 2004;Serrano et al, 2002). Calcium (Ca) is thought to play an integral role in stabilizing cell membranes and slowing tissue degradation (Saure, 2005).…”

“…Lester and Grusak (2004) reported that multiple foliar Ca applications increased fruit tissue Ca, improving flesh firmness and storage life of honeydew, but not muskmelon. Only in studies conducted in soilless culture has manipulation of nutrient solution Ca concentration yielded significant muskmelon fruit quality effects (Bernadac et al, 1996;Madrid et al, 2004;Serrano et al, 2002). Despite these generally disappointing results, California growers commonly apply soluble Ca fertilizers such as calcium nitrate, calcium thiosulfate, and calcium chloride to melons during fruit development; application through drip irrigation is particularly popular.…”

Mapping Fruit Susceptibility to Postharvest Physiological Disorders and Decay Using a Collection of Near-isogenic Lines of Melon

“…excessive irrigation in periods with high insolation, shading, or unbalanced fertilization (Cornillon et al, 2000;Madrid et al, 1997Madrid et al, , 2001Nishizawa et al, 1998Nishizawa et al, , 2004a. The disorder symptoms include a glassy texture of the flesh and water exudation (a watercore disorder), accompanied by flavor degradation with a tendency to alcoholic fermentation, normal levels of flesh sugars, excessive softening, and increased polygalacturonase activity, intercellular spaces, and membrane permeability (du Chatenet et al, 2000;Madrid et al, 1997;Nishizawa et al, 2004b;Serrano et al, 2002). The watersoaking disorder is characterized by lower calcium concentration in the NaCl-soluble fraction of the mesocarp tissue of the ripe fruit from the basal hemisphere but not in tissue from the inner mesocarp of the distal hemisphere (Nishizawa et al, 2004a).…”