Effects Of Water And Light Interaction On Photo Energy Utilization And Dissipation In Ginger Leaves

Ginger （Zingiber officinale Rosc.） originated from tropical rain forest area, thedistribution of root system is shallow, large on the water demand, production are shadingcultivation, in order to alleviate water stress on the adverse effects of ginger. In order to studythe response of ginger on moisture and light intensity, this study uses the PEG-6000droughtand shade50%simulated interactive processing, research the interaction on utilization anddissipation characteristics of ginger light, discussed the signal of ABA on the regulatory roleof the theoretical basis, to reveal the ginger shading cultivation, provide theoretical basis forcultivation technique of ginger to reform the traditional shading. The main results are asfollows:1. Through studied the effects of different treatments such as Natural light （T1）, Shading50%（T2）, Light drought （T3）, Shading drought （T4） on leaf chlorophyll fluorescenceparameters and photosynthetic parameters of potted ginger through interactive treating withPEG-6000and shading50%. The results showed that Fv/Fm,ФPSⅡ, qP and Pnof gingerleaves in T3, T4reduced constantly during stress treatment, meanwhile NPQ increased, andthe amplitude of T3was significantly higher than T4, but T1and T2had no significant change.Fv/Fm, ФPSⅡ, qP in all treatments reduced significantly at noon, the largest decreaseamplitude was got by T3, and follwed by T4, while NPQ had opposite change trend. Gingerleaves of different treatment hibited different characteristics of Pndiurnal variation, thehighest Pnwere got by T1, T2, followed by T4and the lowest was T3. During the stresstreatment, Ciand Lsin T1, T2all had no significant change, but Ciin T3and T4increased andLsreduced after1and3days of stress treatment respectively. After six-day stress, although Pnreduced sigificantly in all treatments at midday, Lsin T3, T4decreased along with Ciincreased. The results showed that active oxygen content and antioxidant enzyme activity ofginger leaves in T1, T2had no significant change, but O₂^-., H₂O₂and MDA content in T3, T4increased constantly, and the activity of SOD, POD and CAT were increased first and thendecreased, on the ninth day of treatment the O₂^-., H₂O₂and MDA content of ginger leaves inT3, T4were higher168.45%,195.24%,206.95%and92.67%,101.19%,128.03%thanuntreated respectively. The content of O₂^-.、H₂O₂and MDA content in all treatments increasedsignificantly at midday, T3showed highest change, followed by T4, and then T1、T2, theactivity of SOD and POD in all treatments and CAT in T3, T4decreased significantly,meanwhile CAT of ginger leaves in T1、T2showed higher activity. According to the study we concluded that drought stress could lead to active oxygen accumulation of ginger leaves, andstrong light could aggravated damage degree; but single natural light did not cause obviousoxidative damage in ginger leaves under normal water supply condition.2. Through studied the effects of different treatments such as Natural light+Water control（T1）, Shading50%+Water control （T2）, Natural light+10mmol/L IA （T3）, Shading50%+10mmol/L IA （T4）, on leaf chlorophyll fluorescence parameters, Mehler Reaction,Photorespiration and the activity of SOD, APX of potted ginger through interactive treatingwith leaf-surface spraying of10mmol/L iodoacetamide （IA） and shading50%. The resultsshowed that Pnand Fv/Fm of ginger leaves in T3, T4reduced constantly during treatment, Pndecreased by64%and33.16%respectively in the ninth day of treatment, meanwhile Fv/Fmdecreased by16.49%and10.89%, Mehler Reaction increased by139.38%and72.56%respectively, Pr/Pnincreased by43.98%and13.74%respectively and the activity of SOD andAPX were significantly higher than those of the control, yet T1, T2had no significant change.In the sixth day of treatment, Pnand Fv/Fm in all treatments reduced significantly at noon,Mehler Reaction and the activity of SOD and APX of leaves increased markedly, the largestamplitude was got by T3, followed by T4, and then T1,T2. So it is clear that Mehler Reactionand the activity of related reactive oxygen scavenger enzymes were enhanced, especiallywhen Pnof ginger leaves was inhibited by exogenous IA, this suggested that water-watercirculation and Photorespiration played an essential role in dissipating excessive light energyof ginger leaves.3. By spraying method, studied the effects of different treatments such as T1(0mmol·L^-1ABA), T2（20μmol/L ancymidol）, T3(0.05m mol·L^-1ABA), T4(0.1mmol·L^-1ABA)on leaf photosynthetic parameters, chlorophyll fluorescence parameters and themetabolism of active oxygen. The results showed that Pnand Fv/Fm of ginger leaves in T3,T4reduced constantly during stress treatment, but active oxygen and MDA increasedsignificantly. Pndecreased by37.42%and84.96%respectively in the ninth day of treatment,meanwhile Fv/Fm decreased by23.29%and45.21%, MDA contant increased by133.33%and188.58%respectively; At present, the Pnand Fv/Fm of T2were higher5.02%and6.73%than T1, but the MDA contant were decreased by19.66%. According to the study weconcluded that exogenous ABA can decrease the Pnin ginger leaves, aggravatedphotoinhibition and the degree of membrane lipid peroxidation.