利用叶绿素荧光和820 nm光反射探究苹果发育过程中果皮光合能力变化OA

Taking'Honeycrisp'apple fruits as the test materials,the synchronous measurements of prompt fluorescence,delayed fluorescence,and 820 nm light reflection were carried out to compare the changes in photochemical reactions and photosynthetic electron transfer capacity of the two photosynthetic systems in sun-exposed and shaded fruit peels at different fruit developmental stages,in order to provide reference for breeding and cultivation management of anti-sunburn new cultivars of unbagged apples.The results showed that for young apple fruits,the capacity of photosystem Ⅱ (PSⅡ)photochemical reactions in the sun-exposed peel and shaded peel was comparable,but the capacity of PS Ⅰ photochemical reactions was relatively higher in the sun-exposed peel.As fruit developed,the photosynthetic electron transfer capacity at the donor and acceptor sides of PS Ⅱ decreased faster in the sun-exposed peel than that in the shaded peel.The photochemical reaction capacity of PSⅠ also decreased faster.However,fruit coloring could reduce the photodamage to both PSⅡ and PS Ⅰ.