The Effects Of Cross-pollination On Fruit Quality And Organic Acid Components In ’Guanximiyou’ Pummelo (Citrus Grandis)

In this study, the juice sacs of self- and cross-pollination ’Guanximiyou’ pummelo (Citrus grandis) were used as the experimental material to explore the effects of cross-pollination on Citrus grandis juice sacs organic acid metabolism. These results mainly provides the basis to further study fruit quality molecular mechanism. The main results are as follows:1. Determination and analysis of soluble solids, titratable acid, citrate, isocitrate and malate in normal and granulated juice sacs. The results showed that cross-pollination improved content of soluble solids and titratable acid; The content of the citrate and malate was increased in fruit juice sacs of cross-pollination, while isocitrate content is lower. In granulated juice sacs, the citrate content was markedly decreaed, the isocitrate content increased.2. Determination of the 11 organic acids metabolic enzyme activity, NADP-ME, NAD ME, CS, ACO, PEPC, NADP-MDH, NAD-MDH, PK, NADP-IDH, NAD-IDH and PEPP, on self- and cross-pollination pummelo. There was a greater influence on the activity of 10 enzymes related to organic acids, ACO, NAD-IDH, NADP-IDH, NAD-MDH, NADP-MDH, NAD-ME, NADP-ME, PEPC and PK, in cross-pollination fruit juice sacs. But it had little effect only for PEPP.3. 11genes related acid metabolic enzymes, NADP-ME, NAD-ME, CS, MAC OS, PEPC, NADP MDH, NAD-MDH, PK, NADP-IDH, NAD-IDH and PEPP, were analyzed by qPCR. The results showed that the metabolic enzyme gene expression had no effect in cross-pollination normal fruit juice sacs. The gene expression of NADP-ME, NAD-ME, cyNAD-MDH, CS and ACO were increased in granulated juice sacs, while it was decreaed on NAD-IDH and NADP-IDH gene. In addition, these was no difference on gene expression of PEPC,PK and mMDH.