Effects of Differing Deficit Irrigation Treatments on Fruit Quality of Citrus reticulata Blanco
Clemenules mandarin citrus trees grafted on two rootstocks ( Cleopatra mandarin and Carrizo citrange) were subjected to three irrigation treatments; the control treatment (100％ ETc) , Phase II treatment (non-irrigation during phase II of fruit growth) and Phase M treatment (non irrigation during phase HI of fruit growth). The two drought treatments affected in different ways some fruit quality parameters and these effects were also dependent on the rootstocks. Phase E -stressed fruits had higher TSS and TA than control fruits; the TSS/TA ratio decreased to below an acceptable level, indicating an important delay in the maturation process. This was also observed by the decrease of the a/b ratio relative to control fruits. Phase HI stressed fruits also had higher TSS and TA, but the TSS/TA ratio increased to values similar to those of control fruits. Phase II -stressed fruits from Cleopatra had increased fructose, sucrose and glucose with respect to control fruits. Carrizo trees suffered a high level of stress during this phase, producing an increase of fructose and glucose levels whilst sucrose decreased, suggesting that sucrose hydrolysis contributed to the fruit osmotic adjustment. This reduced the non-reducing/reducing sugars ratio in fruits from Carrizo whereas it increased in fruits from Cleopatra. Phase IIIstressed fruits had increased glucose and sucrose, independent of the rootstock, and the nonreducing/reducing sugars ratio also increased. The total phenolics increased in both drought-stress treatments, with respect to the control, but this increase was higher for Phase II-stressed fruits. However, only Phase II -stressed fruits had a higher ascorbic acid level than control fruits. The juice percentage of Phase II -stressed fruits was decreased with respect to control values. So, the increases of TSS, TA, sugars, ascorbic acid, total phenolics, lycopene and β-carotene found in this treatment could be due to both new synthesis, in response to water stress suffered by the tree, and to the lower fruit water content, since it is in this phase when the highest increase in juice content takes place. However, Phase IIIstressed fruits had a higher juice percentage than control fruits, so their increases of TSS, TA, total phenolics, total sugars and lycopene were due to new synthesis. Phase III stress increased the fruit quality by increasing some quality parameters without alterations of maturation process with respect to control fruits. However, phase II treatment also increased some quality parameters but produced a drastic delay in the maturation process that made them non-commercial.
TSS Acidity Maturity index Sugar accumulation Total phenolics Carotenoids Ascorbic acid Antioxidant activity Cleopatra mandarin Carrizo citrange
J. M. Navarro A. G. Gomez-Gomez J. G. Perez-Perez I. Porras P. Botia
Departamento Citricultura, IM1DA, C/Mayor s/n La Alberca 30150, Murcia, Spain Departamento Citricultura, IM1DA, /Mayor s/n La Alberca 30150, Murcia, Spain
国际会议
11th International Citrus Congress(第11届国际柑橘大会)
武汉
英文
701-706
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）