选择性光技术对‘阳光玫瑰’葡萄光合特性和果实品质的影响

Effects of pink fluorescent filming and pink netting on the photosynthetic characteristics and fruit quality of‘Shine Muscat'grape

【目的】研究选择性光技术对葡萄叶片光合特性及果实品质的影响。【方法】以‘阳光玫瑰’葡萄为材料,利用Li-6400光合测定仪测定不同生长期叶片的光合响应曲线,并应用直角双曲线修正模型对其进行拟合。通过利用粉红色荧光薄膜和网罩处理研究选择性光技术对葡萄叶片光合特性及果实品质的影响。测定红膜、红网对‘阳光玫瑰’葡萄叶片不同生长期的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间二氧化碳浓度(Ci)等光合生理指标以及对果实纵径、横径、单果质量、可溶性固形物和可滴定酸含量等果实品质的影响。【结果】与对照相比,红膜、红网处理对不同时期葡萄的Pn、Gs和Tr都有明显促进作用,降低了Ci;红膜、红网处理可以提高果实纵、横径和单果质量,可促进葡萄提早成熟。果实品质红网与红膜差异不大,显著高于对照。【结论】葡萄选择性光技术可以提高‘阳光玫瑰’葡萄的光合能力和果实品质,有利于葡萄生长。

[Objective]The objective of the study was to elucidate the effects of selected light technique on the photosynthetic characteristics and fruit quality of ＇ Shine Muscat＇ grape. Selected light technique is ap- plied to maximize crop photosynthesis, which had been studied by researchers in Tokyo University, Ja- pan. Because plants need short wavelength （245 nm） for photosynthesis, they used polymeric fluorescent dyes to enhance the effect of red wavelength on photosynthesis. In this experiment, we used the pink fluo- rescent film or pink net cover to change the light quality in greenhouse, and observed the effect on the photosynthetic characteristics and fruit quality of ＇Shine Muscat＇ grape. [Methods]The experimental ma- terials were five-year-old vines of ＇Shine Muscat＇ grape, which were planted in a greenhouse. On both sides of the rain shelter, small arch sheds were set up. The sheds were covered with pink fluorescent film or pink net as the treatments, and the greenhouse with no shed as the control （CK）. Photosynthetic and physiological indexes including net photosynthetic rate （Pn）, stomatal conductance （Gs）, transpiration rate （Tr）, intercellular CO2 concentration （Ci） of the exposed middle leaves （the 6th or 7th blade） in differ- ent growth periods （at blooming from May 5 to 7; young fruit stage from June 15 to 17; the second berry expansion period from July 25 to 27 ; and berry mature stage from September 1 to 3） were measured with a Li-6400 photosynthetic system on sunny days from 9： 00-11： 00. During the measurements, flow ratewas set at 500 μmol·m^-2·s^-1, light intensity ranged from 0-2 000 μmol·m^-2·s^-1 （0, 20, 50, 100, 200, 400, 600, 800, 1000, 1 200, 1 600 and 2 000 μmol·m^-2·s^-1）. The effects of the treatments on fruit qual- ities, such as the fruit length, width, fruit weight, soluble solids and titratable acids were examined. From August 10, 30 berries of moderate size from every cluster were sampled randomly every 5 days. Length and width of grape fruit were measured with an electronic digital caliper, and a 1/100 g electronic balance was used to obtain fruit weight. Determination of soluble solid content was carried out with a hand-carried RA-250 reflectometer, and titration method was used to measure titratable acid content. [Results]The changes of Pn with light intensity fitted well with corrected rectangular hyperbole model. As the light intensity increased, the change trends of photosynthetic rate in different treatments at the same stages and in different stages under the same treatments were different. From the change trends in the four stages, the photosynthetic rate was in the order of pink fluorescent film 〉 pink net 〉 CK, and the photo- synthetic rate in the same treatments increased gradually with time. Pink fluorescent filming and pink net- ting treatments improved the photosynthetic capacity of grape leaves, and thus were favorable for the pho- tosynthate accumulation. The trends of stomatal conductance and transpiration rate were consistent with photosynthetic rate, while the intercellular CO2 concentration in the treatments of pink fluorescent filming and pink netting were lower than the control at all stages. In comparison with the control, filming and net- ting also increased fruit length by 3.53% and 4.16%, diameter by 9.74% and 10.33%, and fruit weight by 9.72% and 10.33%, respectively. The treatments had impacts on fruit sugars and acids. The contents of soluble solids in filming and netting treatments were higher than the control in the early stages, but had no significant difference in the late stages, while an opposite trend was observed in the contents of titrat- able acids, which were lower in the filming and netting treatments than the control in the early stages but basically the same in the late stages. In addition, the treatments could advance fruit maturation. There was no significant difference in fruit quality between filming and netting treatments, both of which signifi- cantly increased fruit quality compared with the control. [Conclusion]In conclusion, pink film cover and pink net cover treatments increased photosynthetic rate and stomatal conductance in ＇Shine Muscat＇ grape. During the same periods, net photosynthetic rate in pink filming treatment was the greatest. As the berry matured, leaf photosynthetic rate increased until full maturity, and it was similar during the berry growth periods. In addition, pink filming and netting increased fruit weight, longitudinal diameter, trans- verse diameter and other fruit quality indexes. Effects of pink fluorescent filming and pink netting were not significantly different. Changes in light quality have significant impact on photosynthesis characteris- tics as well as their growth in fruit trees. Through the simple method of changing light intensity and quali- ty, photosynthesis and fruit quality can be improved. Thus, selected light technique has a significant role in improving photosynthetic capacity, fruit growth and quality of ＇Shine Muscat＇ grape, and may be ap- plied to other fruit trees.