Study On Variations Of Volatile Ingredients And Citrus Flavonoid Of Infection Phytophthora Parasitica Of Citrus

Parasitic Phytophthora is pathogens which seriously threat both leaves and fruits of citrus plants. It has extensive range of host, and in the condition of both high temperature and humidity, the condition which is considered one dominant factor, Parasitic Phytophthora could be the main pathogenic factor causing the foot rot of citrus plants. Based on the results of the experimental identification on resource resistance of citrus, the research conducted by Huang jinglong, Citrus aurantium L、Citrus junos Siebold.ex Tanaka、Poncirus trifoliata Raf and Citrus limonia Osbeck are resistance resources; Citrus sinensis、Citrus bergamia Risso, Cirtrus Medica are susceptible resources. To reveal the resistance mechanism of citrus resources, it is necessary to further the study of the change in functional components (volatile substances and flavonoids), the change occurs when Parasitic Phytophthora is inoculated. We selected six varieties of citrus among which Citrus reticulata Blanco^two Citrus sinensis (L.) Osbeck and Citrus medica L are susceptible resources and Citrus limonia Osbeck and Poncirus trifoliata Raf are resistance resources. The aim of this experiment was to use Headspace soild phase micro extraction, gas chromatography-mass spectrometry (HS-SPME-GC-MS) and Ultra performance liquid chromatography (UPLC) to explain the differences in the contents of volatile substances and of flavonoids from different parts of the6citrus. The main findings are provided below:1. Optimization of conditions needed to extract a volatile substance from citrus.To optimize the extraction of volatile components from navel flesh, we used single factor to investigate extracting conditions. The optimum conditions for the SPME extractions of the volatile compositions from navel flesh are obtained as follows:sodium chloride1.0g, Incubation temperature50℃, pre-incubation time25min, extraction time40min. The optimum conditions for the SPME extractions of the volatile compositions from navel peel are obtained as follows:sodium chloride1.0g, Incubation temperature50℃, pre-incubation time20min, extraction time50min.2. The volatile of citrus plant was a complex mixture of several components which included terpenes, alcohols, aldehydes, esters, ketones, C6compounds and others. The main compounds were limonene. linalool, γ-terpinene, caryophyllene, neral, citral and so on.3. Changes in contents of volatile substances of5citrus plup varieties. 106volatile compounds were identified in pulp from five genotypes, and there are34、34、38、59and44volatile compounds in hongrouqicheng、yangxiwanlu、xiangyuan、xiacheng and ningmeng. Detectable amount was2586.17μg.g-1、1283.19μg.g-1、5291.99μg.g-1、599.27μg.g-1and716.26μg.g-1. The highest total content was alkenes. The relative content of more than85%, wherein the limonene is the maximum content of the composition. Followed alcohols and aldehydes. Different varieties of pulp composed of volatile substances with different characteristics, there are some differences in the composition of the material.147volatile compounds were identified in pulp from five genotypes, and there are55、61、65、69and57volatile compounds in hongrouqicheng、yangxiwanlu、xiangyuan、xiacheng and ningmeng. Detectable amount was1777.51μgg-1、2596.64μg g-1、2389.02μg g-1、487.59μg g-1and575.14μg g-1. Citrus after injury, volatile components occurred some changes, but in different species show some differences. The most abundant class of terpene component relative content of more than95%, either limonene is the main ingredient. Citron characteristic is manifested more aromatic group-containing compound other than the several varieties of the main substance is3,7-Dimethyl-1,6-octadien-3-yl2-aminobenzoate.147volatile compounds were identified in pulp from five genotypes, and there are65、64、57、84and64volatile compounds in hongrouqicheng、yangxiwanlu、xiangyuan、xiacheng and ningmeng. Detectable amount was1283.27μg g-1、1384.27μg g-1、752.32μg g-1、402.56μg g-1and507.54μg g-1. Citrus disease after volatile matter content in different varieties were decreased by27.81%,46.69%,68.51%,17.44%and11.75%, the most significant changes of citron, lemon the most was not significant. Volatile components in the change in the class is one of the most obvious terpene D-limonene. In to reduce the proportion of various varieties were156%,93%,48%,179%and236%.4. Changes in contents of volatile substances of5citrus peel varieties.135volatile compounds were identified in pulp from five genotypes, and there are73、63、54、47and49volatile compounds in hongrouqicheng、yangxiwanlu、xiangyuan、xiacheng and ningmeng. Detectable amount was3275.82μg g-1、7302.25μg g-1、14111.10μg g-1、1852.33μg g-1and2039.25μg g-1. Citrus peel volatile detected in more than content to be rich in volatiles same plup on which the relative content of the most abundant alkenes declined more than60%of its alcohol higher than the proportion of content than where the plup is also greatly improved. Citron also contains rich aromatic compounds, the main component was3,7-Dimethyl-1,6-octadien-3-yl2-aminobenzoate.143volatile compounds were identified in pulp from five genotypes, and there are103、76、57、76and76volatile compounds in hongrouqicheng、yangxiwanlu、xiangyuan、xiacheng and ningmeng. Detectable amount was1074.381μg g-1、6715.52μg g-1、13679.77μg g-1、1528.69μg g-1and3438.92μg g-1. Citrus after injury, volatile components occurred some changes, but in different varieties showed some differences, Cara Cara orange, citrus and stayed in late Lo citron content decreased, Valencia orange and lemon content increased. The most abundant component of the relative content of terpene olefins dropped to more than37%, either limonene is the main ingredient. Citron any performance contains more than a few other varieties of aromatic group of compounds3,7-Dimethyl-1,6-octadien-3-yl2-aminobenzoate.204volatile compounds were identified in pulp from five genotypes, and there are114、75、64、70and75volatile compounds in hongrouqicheng、yangxiwanlu、xiangyuan、xiacheng and ningmeng. Detectable amount was2014.55μg g-1、4992.29μg g-1、9385.86μg g-1、1799.32μg g-1and5386.32μg g-1. After treatment of citrus bacteria volatiles content than the injury group showed inconsistent differences, where the most significant decline citron, Cara Cara rising the most significant. Volatile components in the most obvious change are the terpenes limonene. Including a25.98%drop in navel orange, and a25.66%drop in ponkan and incense margin fell by31.39%, xia Chen increased by17.7%, red quinoa lemon increases by208.09%. Volatile components in the change in the class is one of the most obvious terpene D-limonene, in navel orange accounts for106%of the proportion of the volatile component drop, accounts for77%of the proportion of the decline in ponkan, accounts for54%of the proportion of the fall in with, accounts for104%of the proportion of the rise in the xia Chen, the red quinoa accounts for27%of the proportion of the rise of lemon. The red quinoa and lemon on the rise in the proportion of higher material and (-)-4-terpineol, alpha terpineol, alpha pinene, beta pinene, myrcene and pine oil.5. Changes in11varieties flavonoid content in five kinds of citrusFlavonoid contents in qicheng, penggan, xiangyuana were reduced and those in ningmeng and xiacheng were increased. The flavonoid content in xiangyuan reduced most, meanwhile that in ningmeng increased most. Overall, flavonoids contents did not change significantly.The study has shown for the first time that it is Possible to detect the changes in the contents of volatile substances and of flavonoids when plants are infected with Parasitic Phytophthora diseases by using GC/MS and HPLC. The difference is the kind of change can detect infected citrus disease provide some reference.