The Aromatic Constituents And Drought Resistance And Evaluation Of Rootstock's Flooding Tolerance In Kiwi Fruit

The aroma components of five kinds of kiwifruit were studied to find out the main differences in the aroma of the kiwifruit and the aroma components of the kiwifruit.The aroma components of five kiwifruit varieties were determined by solvent extraction and gas chromatography-mass spectrometry,and the contents were quantitatively analyzed by internal standard method.Through the classification and principal component analysis,the characteristics of the aroma between the varieties were studied.The results showed that: a total of 101 species were detected in the 5 kiwifruit varieties.QiHong,JinMi,Xu Xiang,Hayward,sungold were detected 33,31,39,31,and 34 aroma substances,main aroma substances including hexanol,trans-2-hexenol,trans-2-hexenal,2,4-dimethylbenzaldehyde,2,4-Di-tert-butylphenol,palmitic acid,(2-methylallyl)diethyl fumarate.The aroma components of the new varieties of QiHong and JinMi kiwifruit were unique.In addition to the small differences in aromaticity between Xuxiang and Hayward kiwi,there were significant differences in the aroma components and contents between different kiwifruit varieties.According to the difference of the main species aroma,the five kiwifruit varieties can be divided into three categories: QiHong,JinMi with alcohol,aldehydes,phenols,acids as the main aroma of "fresh-smelling sweet kiwifruit" kiwifruit,Xu Xiang and Hayward are kiwifruits with aromas of alcohol,aldehydes,phenols,and esters as their main aromas of "fresh-smelling fruit kiwifruit".Sungold Fruits use aromatic alcohols,aldehydes,and phenols as the main aroma of fragrance.Type "fresh-smelling kiwifruit".18 indicators related to drought resistance,including leaf area,density,thickness of upper epidermis,thickness of lower epidermis,thickness of leaf,thickness of palisade tissue,thickness of sponge tissue,CTR,SR,wide pore,Stomatal length,stomatal width,stomatal area,stomatal density,electrical conductivity,malondialdehyde,water loss rate,chlorophyll a/chlorophyll b.17 indicators with larger coefficient of variation were selected to compare the drought resistance of four kiwifruit varieties/materials by membership functions.The results were as follows: Gezao> JinMi> Xuxiang> QiHong.Further analysis of the grey correlation and relatedness classification,according to the correlation index and degree of association of each indicator,five indicators with strong correlation with drought resistance,the most typical one were selected: leaf area,stomatal density,leaf thickness,and malondialdehyde.Aldehyde and pores are wide.According to the five indicators after screening,the drought resistance of the four kiwifruit varieties/materials was compared by the membership function.It was still Gezao> Jin Mi> Xuxiang> QiHong,and compared with the original membership function average,the difference was in the range of 0.0332-0.0685.The results showed that the selection of leaf area,stomatal density,leaf thickness,malondialdehyde,and stomatal apparatus width can be used to accurately compare the drought resistance of kiwifruit by the membership function.With the prolongation of flooding time,the intercellular carbon dioxide concentration in kiwifruit increased,the stomatal conductance,transpiration rate,and net photosynthetic rate showed a downward trend,and the photosynthetic characteristics of the leaves were inhibited by flooding stress.The degree of inhibition was as follows: There was no significant difference in photosynthetic indexes between DuiE and Qinmei flooding for 10 days(P<0.05).And Affected degree:Ge Zao > DuiE > QinMei.After 10 days of flooding stress,the fluorescence characteristics of leaves were also inhibited.The maximum photochemical quantum yields of PSII in the three samples decreased by 11.59%-22.75%,the photosynthetic electron transport rate decreased by 21.19%-29.50%,and the photochemical energy conversion effective quantum in PSII system.The efficiency decrease ranged from 19.44% to 32.45%,and the minimum fluorescence yield increased by 70.68% to 112.90%.Ge Zao was the most inhibited.After 10 days of flooding,root activity decreased and cell membrane permeability increased.The root activity and non-flooded water in the three areas decreased by 39.80% to 65.80%,and the electrical conductivity increased by 151.20% to 313.55%.The damage degree of the Ge Zao was extremely significant,and the DuiE and QinMei were not affected after flooding and flooding for 10 days.The seedlings are relatively light.From the internal structure of the roots,the waterlogging stress destroyed the structure of the root cells,and the structural damage to the DuiE and the QinMei was lighter,and the structural integrity of the Ge Zao was seriously damaged.After 10 days of flooding,the epidermal cells of the upper roots of GeZao was broken,the damaged vascular bundles were damaged,the vascular bundles were damaged,the lower root epidermal cells and the central column were completely festered,and the upper root cortical cells of the cuttings were not damaged.The fine structure of the middle column was intact,and the lower root system was exfoliated,and most of the parenchyma cells and cortical cells collapsed;the gap between the upper root cortex cells and the center column of the QinMei became larger,the lower root epidermis was damaged,and the cortical cells became evacuated.The column was deformed by some damage.From the perspective of external morphological changes,under the flooding stress,the stem holes at the near surface of DuiE became hypertrophic,some parts grew adventitious roots,and with the leaves falling off,new leaves were drawn from the lower end.It is a typical flooding adaptation mechanism.In summary,from the impact of flooding on the leaves and root organs,the resistance to pod borer of Ge Zao was poor,and the resistance to pods of DuiE and QinMei were strong,and DuiE was stronger for Flooding adaptation mechanism.