Effects Of Jasmonates On Coloration And Quality Of Grape Berry

Seven-year-old ‘Jingxiu’ and ‘Christmas Rose’ grapevines were used as plant materials in this study. Two different concentrations(100 mg/L, 50 mg/L) of prohydrojasmon, methyl jasmonate were respectively applied on ‘Jingxiu’ and ‘Christmas Rose’ grapewine berry. The aqueous solutions of both treatments and control involved 0.1% Tween-80 and 1% ethanol. The experimental grape berries were sprayed uniformly with aqueous solution twice at the beginning of veraison and 7 days after the first application. The effects of PDJ or Me JA treatment on improving coloration and quality of ‘Jingxiu’ and ‘Christmas Rose’ grape berry were studied in this thesis. In addition, the effects of PDJ or Me JA treatment on expression of genes related to the synthesis of anthocyanin were also analyzed. The main results are as follows:1. During the ripening period of grape whether treated or not, anthocyanin content rose gradually, in contrast chlorophyll declined gradually in the berry skin, while carotenoids in the berry skin rose at first, then dropped; L* value, b* value decreased while a* value, CIRG value increased. Compared with control, the content of anthocyanin in the berry applied with PDJ, Me JA was obviously higher while the content of chlorophyll and carotenoids in the berry applied with PDJ, Me JA were lower. Grape berries treated with PDJ, Me JA had higher a* value, CIRG value and lower L* value, b* value than control. At harvest, anthocyanin content in the‘Jingxiu’ and ‘Christmas Rose’grape applied with 100 mg/L PDJ was respectively 49.8%, 38.1% higher than control. The CIRG value of ‘Jingxiu’ and ‘Christmas Rose’grape treated with 100 mg/L PDJ reached 4.32 and 4.58 respectively while the CIRG value of untreated grape was only 3.77 and 3.91 respectively at harvest.2. Soluble solids content of grape berry treated with PDJ or Me JA was obviously higher compared with grape untreated. PDJ, Me JA treatment significantly promoted the accumulation of total phenolics and flavonoids in the berry skin. In addition, PDJ, Me JA treatment did not have a negative effect on berry weight, berry length and berry diameter. Pedical endurable pulling force and berry endurable pressing force were also not influenced by PDJ, Me JA treatment, and the phenomenon of berry loss did not happen in treated grape.3. During the ripening period of grape, the expression of genes Vv DFR and Vv LDOX increased at first, then dropped. The expression of genes Vv UFGT and Vv MYBA were low at the beginning of veraison, as the grape was ripening, the expression of genes rose swiftly until reaching the top, then dropped. Compared with control, PDJ or Me JA treatment promoted the expression of genes Vv DFR, Vv LDOX, Vv UFGT and Vv MYBA. PDJ treatment had a better effect on promoting the expression of genes related to the synthesis of anthocyanin than Me JA treatment.4. Two different concentrations of exogenous PDJ and Me JA treatment can improve coloration and quality of ‘Jingxiu’ and ‘Christmas Rose’ grape berry. When it comes to improve coloration and quality of grape berry, PDJ had a better effect than Me JA with the same concentration and 100 mg/L PDJ, Me JA showed a better effect than 50 mg/L PDJ, Me JA respectively. Among all the treatments, 100 mg/L PDJ was the most effective in improving coloration and quality of grape in the experiment.