一氧化氮（NO）熏蒸提高哈密瓜果实采后贮藏的耐冷性

Enhancement of Chilling Tolerance of Hami Melon Fruits in Postharvest Storage Period by Using Nitric Oxide Fumigation

摘要:

为了探究一氧化氮（nitric oxide，NO）熏蒸对哈密瓜采后耐冷性的影响。以“西州密25号”为试材，用60 μL/L NO气体熏蒸3 h，分别在（1±0.5 ℃）、（3±0.5 ℃）、（5±0.5 ℃）贮藏。统计冷害发病率和冷害指数，测定过氧化氢酶（catalase，CAT）、过氧化物酶（peroxidase，POD）、超氧化物歧化酶（superoxide dismutase，SOD）活性、超氧阴离子（superoxide anion，O2ˉ·）产生速率、过氧化氢（hydrogen peroxide，H2O2）含量的变化。结果表明：NO处理能提高SOD、POD活性，抑制O2ˉ·产生速率。1 ℃条件下，果实冷害发病率最高，NO处理能减轻冷害的发生；3 ℃条件下，对照果实后期出现冷害，但NO处理果实无冷害发生；5 ℃条件下，果实后期出现冷害和病害症状，NO处理能减轻果实的冷害和病害。说明NO能够提高抗氧化相关酶的活性，抑制活性氧（reactive oxygen species，ROS）的积累，提高果实的耐冷性；3 ℃条件下，NO熏蒸既能有效维持果实的贮藏品质又能抑制果实冷害的发生。

Abstract:

The effects of nitric oxide (NO) fumigation on chilling tolerance of Hami melon fruit in postharvest storage were investigated. The muskmelon fruit, 'Xizhoumi25' muskmelon, was used as a test material and was fumigated with 60 μL/L NO for 3 h and stored at (1 ± 0.5℃), (3 ± 0.5℃) and (5 ± 0.5℃), respectively. The chilling injury incidence and chilling index were counted. The activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), the production rate of superoxide anion (O2ˉ·) and the content of hydrogen peroxide (H2O2) were determined regularly. The results showed that NO treatment could increase the activities of SOD and POD and inhibit the production rate of O2ˉ·. At the storage temperature of 1℃, the incidence of chilling injury was the highest and the occurrence of chilling injury was reduced by NO treatment. At the storage temperature of 3℃, the chilling injury incidence occurred slightly in the control fruit , but the chilling injury was inhibited by NO-treatment. When the storage temperature was 5℃, the chilling injury and disease symptoms occurred in the late storage period, and the chilling injury and disease were alleviated by NO treatment. The antioxidant enzyme activity was increased and the accumulation of reactive oxygen species (ROS) were inhibited by NO fumigation, thus reducing the chilling injury of fruits. The storage quality of Hami melon fruit could be maintained, and the occurrence of chilling injury could also be inhibited by the NO fumigation treatment at 3 ℃.