Main Biological Characteristics And Storage Properties In Middle And Late-Maturing Peach Varieties

Peach (Prunus persica L.) is one of the leading fruit industry in Zhejiang Province, which holds an important proportion in agricultural economy. At present, the proportion of middle-maturing variety is about 70%, and late-maturing is less than 20%. The irrational product structure leads to some questions, such as market circulation, consumerdemands and sustainabledevelopment of industry. Middle and late-maturing peach varietiesdomestic and abroad are used to research and evaluate on main biological property, harvest maturities and storage characteristic, which are more concerned in recent years, in order to optimize product structure, extend the supply period and provide a theoretical basis for a reasonable choice in Zhejiang. The main contents, and results were summarized as followings:1. Main biological proporty evaluation of several middle and late-maturing peach varieties.'Huangjintao'(yellow-fleshed peach),'Qingshuibaitao' (white-fleshed peach),'Xinchuanzhongdaobaitao'(white-fleshed peach) and 'Qiubaitao'(white-fleshed peach) introduced from Japan, twodomestic cultivar 'Xumi'(white-fleshed peach),'Qiuyulu' (white-fleshed peach) and the other two 'Jinxiuhuangtao'and'Fenghuayulu'being yellow-fleshed and white-fleshed types respectively as controls were evaluated, based on main biological indicators including fecundity, yield, resistance to the tree and quality trait The results showed that the 'Huangjintao'and'Qingshuibaitao' were better than the controls and others in tree resistance, yield strength, peach flavor quality and storage characteristic.2. Storage characteristic evaluation of peach fruit indifferent harvest maturities.'Huangjintao'and'Qingshuibaitao'peach in firm ripe stage (70% ripeness) and physiological ripe stage (80% ripeness) were used to compare quality trait from harvest to full ripeness with storage behavior at 20℃and relative humidity 85-90%. The results showed that at harvestday both'Huangjintao'and 'Qingshuibaitao' 80% ripeness fruit had higher total soluble solids, sucrose and aromatic components; shelf period of 70% ripeness fruit extended for 4d and 2d respectively compared to 80% ripeness fruit. Reached to full ripeness by storage, sugars and aromatic components increased indifferent extents, thus organic acid contents were significantlydecreased in both two maturities, but full ripeness fruit of 80% ripeness fruit had much better flavor quality than 70%ripeness fruit.3. Research on storage characteristic indifferent harvest maturities of 'Jinxiuhuangtao'atdifferent storage temperatures. Studies on changes of quality trait of 70% and 80% ripenessduring storage atdifferent temperatures:30℃,20℃, 7℃and relative humidity 85-90%. The results showed that at harvestday 80% ripeness fruit had much higher a* value and lower firmness than 70% ripeness, thus both total soluble solids and titratable acid were no significantdifference; when the fruit reached to full ripenessduring 20℃storage, both the two harvest maturities had the same storage period for 8d, the full ripeness fruit of 80% ripeness was more colorful, and had higher aromatic components and lower titratable acid; storage periods of the 70% and 80% ripeness fruits were 4d and 3d respectivelyduring 30℃, and color of full ripeness fruit was more faint than two maturitiesduring 20℃storage, which had lower aromatic components and higher contents of acid, alcohol, aldehyde than other two storage temperatures, so the flavor quality during 30℃storage was much worse.7℃storage prolonged storage period to 18d, but the fruit reached to full ripeness had lower aromatic components and higher titratable acid, alcohol and aldehyde. Therefore, harvest maturity of 80% ripenessduring 20℃had best flavor quality and better storage characteristic.4. Assessment of fruit maturity using electronic nose technology. Electronic nose technology combined with quality and physiological indexes was used to evaluate threedifferent maturities; of'Jinxiuhuangtao'peach, including veraison, maturity and ripe stage fruits. Results illustrated that three maturities peach could bedistinguished using the score plot of principal component analysis (PCA) for the electronic nose measurement. However, the result was not good for maturity and ripe stage peach.discriminant factor analysis (DFA) could completelydistinguish from all maturities. For further, compared to the results with the traditional chemical and physical test methods and physiological indexes, the results showed that PCA analysis was more accurate indistinguishingdifferent maturities peaches thandFA.