套袋瑞雪苹果果皮褐变发生规律及其与温度的关系

A study of the characteristics of browning in bagged Ruixue apple fruit and its relationship to temperature

[目的]研究套袋瑞雪苹果(Malus domestica Borkh.‘Ruixue’)果皮褐变发生规律及其与温度的关系。[方法]以瑞雪为试验材料,调查了专用果袋、G果袋处理的瑞雪果实全发育期褐变率,监测果袋内和空气中的温度,分析果袋内外温度差异与褐变率之间的关系。[结果]随着套袋时间的延长,果实褐变率升高,G果袋处理的果实褐变率高于专用果袋;果袋内的日平均温(T_(mean))、日最高温(T_(max))、昼夜温差(TD)、有效积温(GDD)、日最高温积累量(ST_(max))、昼夜温差的积累量(STD)均低于空气中的对应参数,而果袋内的日最低温(T_(min))、日最低温积累量(ST_(min))与空气中的无显著差异;果袋内GDD、ST_(max)、STD的积累速率低于空气中的积累速率,而ST_(min)的积累速率高于空气中的,果袋内温度环境较袋外稳定;果袋内外│△GDD│、│△ST_(max)│、│△ST_(min)│、│△STD│与│△PB│存在极显著相关性,其中│△GDD│、│△STD│与│△PB│的相关性最大,且存在非线性回归关系,说明果袋内外GDD、STD较大的差异是瑞雪果皮褐变发生的关键因素。[结论]果袋内外有效积温(GDD)、昼夜温差的积累量(STD)的差异与瑞雪苹果果实果皮褐变紧密相关,是套袋诱发瑞雪果皮褐变的重要生态因素。

[Objective]In order to explore the effect of temperature factors on browning during fruit development in Ruixue apple,the article studied the relationship of pericarp browning of bagged Ruixue apple(Malus domestica Borkh.‘Ruixue’)with temperature.[Methods]Five-year-old Ruixue trees were used as the experimental material and M26as rootstock.The study investigated the fruit browning rate 90,120,150,160,170,180,190 and 200 days after full bloom.Temperatures in the fruit bag and in the air during fruit development were recorded.The relationship of the temperature difference between the air and the fruit bags and the browning rate was analyzed.[Results]The results showed that with the extension of bagging time,the browning rate of the pericarp of Ruixue apple became higher.200days after full bloom,the browning rate of G bag reached 85.56%and the browning rate in bagging treatment with a special bag type reached 70%.Fruit in G fruit bags started to appear symptoms 150days after full bloom,while those in the special fruit bags begun to appear the symptoms of browning160 days after full bloom.The browning rate of fruit in G fruit bags was higher than those in special fruit bags.From 150 to 200 days after full bloom,the browning rate in G fruit bags was 4.44%to24.44%higher than that in special fruit bags.The daily average temperature(T_(mean)),daily maximum temperature(T_(max)),daily the difference of day and night temperature(TD),effective accumulated temperature(GDD),accumulated daily maximum temperature(ST_(max)),and accumulated daily the difference of day and night temperature(STD)in the fruit bags were lower than in the air.Daily minimum temperature(T_(min))and accumulated daily minimum temperature(ST_(min))had no difference between the fruit bags and the air.From 150 to 200 days after full bloom,GDD in the special fruit bag was 24.0℃to 72.0℃lower than in the air,and STD was 140.2℃to 330.3℃lower than in the air.GDD in G fruit bag was62.0℃to 126.7℃lower,and STD 224.2℃to 467.6℃lower than in the air.The accumulated rate of GDD,ST_(max)and STD in the air were higher than in the fruit bags,while the accumulated rate of ST_(min) in the air was lower.The accumulation rate of GDD in the air,special fruit bag and G fruit bag was3.64,2.66 and 2.34℃·d-1,the accumulation rate of ST_(max)23.02,19.82 and 18.54℃·d-1,the accumulation rate of STD 16.17,12.30 and 11.22℃·d-1,and the accumulation rate of ST_(min)6.85,7.52,and7.32℃·d-1,respectively.From 150 to 200 days after full bloom,the temperature factors inside the fruit bags were quite different from those in the air.The△GDD of the G fruit bags was 38.00℃to 54.72℃lower than in the special fruit bags.△ST_(max) in G fruit bag was 98.60℃to 161.50℃lower than in the special fruit bags.The△STD in G fruit bag was 84.00℃to 137.30℃lower,and△ST_(min)14.60℃to24.20℃lower than in the special fruit bags.│△GDD│,│△ST_(max)│,│△ST_(min)│and│△STD│had a significant correlation with│△PB│,of which│△GDD│and│△STD│had the greatest correlation.In the special fruit bag,the correlation coefficients were 0.881 and 0.88,respectively,while in the G fruit bag,the correlation coefficients were 0.947 and 0.943,respectively,and there was a nonlinear regression relationship among│△GDD│,│△STD│and│△PB│.The big differences in GDD and STD between the inside and outside of the fruit bags were the key factor in the occurrence of peel browning in Ruixue.[Conclusion]The temperature factors inside and outside the bags were quite different in the later stage of fruit development,therefore peel browning in the bagged Ruixue apple was caused by the temperature conditions in the later stage.According to the correlation analysis,the browning of the bagged Ruixue apple was closely related to the lower effective accumulated temperature and the lower accumulation of diurnal temperature difference in the fruit bags.