Chilling injury in both parthenocarpic and pollinated cactus pear fruits
M.T. Luna-Ojeda, R. Cano-Medrano, and J. Cajuste-Bontemps
Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-144. pp. 258-259.
2002
บทคัดย่อ
Chilling sensitivity was evaluated in both parthenocarpic and pollinated fruits of two selections of red-colored cactus pear, ‘Moradasa’ and ‘Solferino’. A combination of growth regulators, AG3 and TDZ was used in order to obtain parthenocarpic fruits while others were open pollinated. Ripe fruit were hand harvested and kept at 5 or 10 0C during 3, 6, 9, 12, 15, 18 and 21 days and then held at room temperature for 0, 2, 4, 6, 8 and 10 days. Membrane conductivity, ethylene evolution, weight loss, total soluble sugar, and titratable acidity were measured. At 10 0C/18 days of cold storage /10 days at room temperature, membrane conductivity was higher in parthenocarpic ‘Solferino’ fruit compared with the rest of the treatments. Ethylene evolution was of 2.2 uL.kg .h in ‘Solferino’ vs 1.6 uL.kg .h of Moradasa fruits, Parthenocarpic ‘ Solferino’ fruit lost 20% of their fresh weight while ‘Moradasa’ fruit lost only 12%, regardless of cold storage treatment. Black spotting was observed in some treatments; however a clear pattern of this disorder was not found. There were no differences in total soluble sugar content nor tritratable acidity among treatments. Under our conditions, the development of chiling injury was affectd more by selection and type of fruit rather than by storage temperature. The use of growth regulators to induce parthenocarpic fruits may explain the differences found between parthenocarpic vs. pollinated fruits.