| Quince(Cydonia oblonga Mill) is an ancient and scarce fruit tree. This experimentselected quinecs which were from seven different origins (Akesu xinjiang, Kashi xinjiang,Beijing, Qufu shandong, Xi’an shanxi, Mingxi fujian and Chile) for test materials, analysedtheir based indicators of fruits, took seeds for seedlings, researched seedlings growth dynamic,the stress resistance and germplasm genetic. The paper discussed quince fruit characters,volatile compounds, phenolic compounds, seedlings stree resistance and DNA fingerprint, themain results were submited as follows:(1) Characters of different regions quince had diversity from appearance character to theinner quality. The weight of quince from Kashi was the biggest one, reached341.27g，Beijingquince was the minimum one, only46.67g. The shape index of quinces was not quite different,it was closed to0.9, The peel color was yellow or green, except Qufu quince’s peel was green.The more special fruit was Kashi and akesu quince, there had arris preiection near tocarpopodium. Mineral elements were also different. The nitrogen content of Xi’anxingqinggong quince was higher than others obviously, the highest content of potassium wasQufu’s, and the differences of other mineral element contents were not significant. ROSenzyme system plays an important role in fruit anti-aging and fruit health level. The SOD,POD activity of Xian xingqinggong and Akesu quince were significantly higher than others.(2) Volatiles of quince fruits from six regions (Beijing, Qufu, Kashi, Akesu pingguoxingand gengliuxing, Zhiwuyuan and Xingqinggong Xi’an, Mingxi fujian) were analyzed bySPME/GC-MS.59compounds were identified from these quinces. Esters, alcohols and acidswere the major constituents.The main volatiles of quince fruits were3-methyl-4-oxopentanoicacid, butanoic acid,2-methyl, ethyl ester;2-methyl-2-butenoic acid, ethyl ester； hexanoicacid, ethyl ester；octanoic acid, ethyl ester. Ester was the major and the most importantcomponents for fruit aroma. And the main components of Beijing, Qufu, Akesugengliuxingand Xi’an xingqinggong quince were esters; the main components of Fujian quince wereacids and esters; the main components of Akesupingguoxing quinces were esters and alkenes.Phenolic compounds were analyzed by HPLC. Different quinces had different fruitbrowning degrees and polyphenol oxidase activity. And the fruit browning degree of Fujian quince was significantly higher than others, reached as0.19; the following was Beijing quince;the lowest was the fruit which from Qufu and Kashi; browing degree of Kashi quince fruitheart part was higher,4.4times than pulp part. The PPO activity of Kashi quince was thehighest, reached as72.55uint/min; the quines from Fujian and Beijing were the second leveland Qufu and Xi’an were the lowest; PPO of Kashi quince fruit heart part was2times of pulppart. A positive correlation was found between fruit browning degree and polyphenol oxidase,they had the same variation trendency.The mainly phenolic acids of quince were chlorogenic acid, p-hydroxybenzoic acid,caffeic acid, coumarin, vanillic acid and ferulic acid, the fruit which from Beijing alsocontained catechins and vanillin, the one from Qufu contained vanillin and syringic acid, theone from Xi’an contained vanillin, the one from Kashi also had vanillin, syringic acid andbenzoic acid. The phenolic acids content of Kashi quince pulp part were significantly higherthan the core part.(3)Quince seedlings which were from different areas had different resistance under waterstress. The seedlings were tolerant of waterlogging but drought. Under the flooded conditions,the various indicators had non-significant change. After being flooded for one and a halfmonths, the stems of seedlings below flooded produced many aerial roots, that meant thequince seedlings adapting to flooding conditions. Under drought conditions, decomposition ofquince seedlings substance was much more than synthetic, the seedlings died after a halfmonths’ handling.Under the drought condition, the net growth of seedlings and root activity weresignificantly reduced, ROS activity and soluble protein were increased at first and thendecreased, or directly reduced. The earlier period elevates was due to that plants tried to repairitself function under the adverse circumstance, the latter decrease was due to seedlings deathand all physiological activity stopped. Photosynthetic parameters also changed under thedrought conditions, such as net photosynthetic rate (Pn), transpiration rate (Tr), and stomatalconductance (Gs) decreased; intercellular CO2concentration (Ci) rised up. Thephotosynthesiss parameter changes of earlier period were mainly because of the stomata limit,and the change of later period was mainly because of the non-stomatal factors, eachphysiological activity had been weakened or stopped, then seedlings died. Under flooded condition, the net growth of seedlings and root activity had decreased,and then recovered, its changed tendency was not obvious difference with the comparison.ROS enzyme activity and the content of soluble protein were increased at first and thenrecovered. Because the seedlings could repair themselves under the adverse circumstance, inthe earlier period elevation occured, and then due to the seedlings adapting this adversecircumstance, all physiological activity restored normally. Photosynthetic parameters alsochanged under the flooded conditions, such as Pn, Tr, and Gs had decreased at first and thenrecovered; Ci had rised up at first and then recovered. The earlier period of photosynthesissparameter change was mainly the leaf stomata limit, and the later period of change wasmainly because of the quince adaptation to water stress, each physiological activity hadrecovered normally.Under drought condition, fluorescence parameter of Fv/Fm, PS Ⅱ, Fv ’/Fm’ hadchanged smoothly at earlier period and then dropped significantly; qP and Prate had reducedat first, then ascended, and decreased finally; ETR had increased at first and then reducedobviously; Drate and Ex had increased during drought treatment. The drought resistibility ofquince could be arranged as Beijing quince, Qufu quince, Akesu gengliuxing quince,Kashiquince, Akesu pingguoxing quince from the largest to the least. Under flooded condition, thechange scope of Fv/Fm, qP, Fv ’/Fm’, Prate, Drate, and Ex was not obviously, ФPSⅡ andETR had reduced at first, then decreased, and finally returned to normal levels. We could haveconcluded that all quinces prevent waterlogging.(4)10pairs of primers were selected to carry on AFLP amplification of quince,determined310total positions and210polymorphic positions. It showed that quince hadlower genetic diversity with an average of0.19%only. Quince which from different regionscould be divided into two categories by cluster analysis, one class of quince was from Fujianwhich was much more special, another class was from Beijing, Qufu, Xian, Kashi,Aksu andChile. |
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