不同砧木对黄果柑果实有机酸含量和酸代谢相关酶活性及基因表达的影响

Effects of Different Rootstocks on Huangguogan Fruit Organic Acid Content,Acid Metabolism-related Enzyme Activity and Gene Expression

为了探究不同砧木对黄果柑果实有机酸含量、酸代谢相关酶活性及基因表达的影响,为黄果柑砧木的选择提供理论依据。以枳壳、红橘、香橙为砧木,黄果柑实生苗为对照进行研究。黄果柑果实以积累柠檬酸为主,香橙砧能够最有效地降低果实有机酸含量,成熟期比实生苗低24.35%;嫁接能够一定程度的降低CS活性,而对PEPC、MDH活性的影响较小;花后250～330 d,ACO和NADP-IDH活性均表现出香橙砧〉枳壳砧〉红橘砧〉CK的趋势;除实生苗外,黄果柑NADP-IDH表达水平与总酸含量间呈显著性负相关,而CS、MDH、ACO与总酸含量均未表现出显著相关性。香橙是黄果柑理想的砧木品种,砧木间果实有机酸差异是ACO和NADP-IDH活性共同作用的结果,且NADPIDH基因的表达可能是影响不同砧木黄果柑果实中有机酸含量的关键限制因子。

In order to explore the effects of different rootstocks on fruit organic acid,acid metabolism-related enzyme activities and the gene expression,to provide theoretical evidence for the selection of the rootstocks. In this experiment with Poncirustrifoliate（ L.） Raf,Citrus reticulate Blanco,C. junos（ sieb.） Tanaka for the rootstocks from Huangguogan seeding as the control for study. Showed that： Huangguogan fruit had been accumulated mainly citric acid,C. junos（ sieb.） Tanaka could most effectively reduce the organic content of the fruit,mature period was24. 35% lower than in the the seedling. Grafting can be reduced to some extent the activity of CS,but has little effect on the activity of PEPC and MDH. 250-330 days after flowering,the ACO and NADP-IDH activity exhibited a trend of C. junos（ sieb.） Tanaka Poncirustrifoliate（ L.） Raf Citrus reticulate Blanco CK. In addition to seeding,Huangguogan fruit between the level of expression of NADP-IDH and total acid content was significantly negatively correlated,there was no significant correlation between CS,MDH,ACO and total acid content. The C. junos（ sieb.） Tanaka is ideal rootstock varieties of Huangguogan,Organic acid content of different rootstocks fruit is the result of combined action of the ACO and NADP-IDH activity,and NADP-IDH gene expression may be the mainly limiting factor of Huangguogan fruit organic acid with different rootstocks.