Study On The Changes In The Contents Of Potassium And Calcium And Magnesium In Litchi Pericarps During The Pericarp’s Coloring And It’s Influences On The Pericarp’s Coloring

Litchi(Litchi Chinesis Sonn.) fruit is one of the important specialties of Hainan province. Fruits of Sanyuehong and Baitangying litchi mature in late March to early April and early to Mid-May respectively in Hainan producing region, and they are two important early-maturing local litchi cultivars. The developments of the pericarp’s coloring and the flesh’s sweetening of Sanyuehong litchi fruits are out of step. It is necessary to study the reasons in order to get the inherently economic benefits of Sanyuehong litchi and guide to formulate the reasonable measures for improving its pericarp’s coloring. In this paper, Sanyuehong and Baitangying litchi fruits were used as experimental materials, and the relationships between the pericarp’s coloring and the changes in the contents of potassium and calcium and magnesium in pericarps had been compared with one another of the two cultivars for two years, then the reasons why the pericrp’s coloring of Sanyuehong litchi lags behind its flesh’s sweetening were discussed at this angle.The major results are the following.1. The solo red color of Sanyuehong litchi pericarp changed quickly before the pericarp getting full red, and that of Baitangying litchi pericarp changed quickly after the beginning of the pericarp turning red. Baitangying litchi pericarp’s a values and its amplification were higher than Sanyuehong litchi pericarp’s. Sanyuehong litchi pericarp got red within14d before the pericarp turning full red, and Baitangying litchi pericarp got red rapidly11d ago before the pericarp turning full red.2. The peaks of the ratio of sugar/acid in flesh of Sanyuehong litchi appeared on22nd April in2012and9th April in2013respectively because of the total of acid in flesh dropped to the bottom, and then that dropped because of the taotal of acid in flesh rising. The ratio of sugar/acid in flesh of Baitangying litchi continued to rise because the total of soluble sugar in flesh continued to rise and the total of acid in flesh continued to drop.3. Sanyuehong litchi pericarp’s coloring and its flesh’s sweetening were out of step, and the pericarp’s turning red lagged behind the flesh’s sweetening for6d in2012and9d in2013respectively. Baitangying litchi pericarp’s coloring and its flesh’s sweetening were in step. The contents of chlorophyll in pericarp of Sanyuehong litchi dropped to the bottom on22nd April in2012and9th April in2013respectively, meanwhile, the ratio of sugar/acid in flesh of Sanyuehong litchi rose to the top. As a result, that the pericarp of Sanyuehong litchi colored abnormally was because of the content of the anthocyanin in the pericarp was too low.4. The pericarp’s coloring of the two cultivars resulted from the contents of anthocyanin in pericarps increasing and that of chlorophyll in pericarps decreasing. There were positive and negative linar correlations between the values of a and h and the contents of anthocyanin in pericarps respectively.5. To Sanyuehong litchi, there were differences in the tendencies of the contents of the total of potassium and calcium and magnesium in pericarp between two years. To Baitangying litchi, there were differences in the tendencies of the contents of the total of potassium in pericarp between two years. The contents of the total potassium in pericarps of the two cultivars were significantly higher than those of the total calcium and magnesium in pericarps of the two cultivars at the same time. The content of the total calcium in pericarp was lower than that of the total magnesium in pericarp at the beginning of the pericarp’s coloring, and it was significantly higher than that of the total magnesium in pericarp at the pericarp’s being full red.6. To Sanyuehong litchi, there were differences in the tendencies of the contents of the water-soluble calcium in pericarp between two years. To Baitangying litchi, there were differences in the tendencies of the contents of the water-soluble potassium in pericarp between two years. The contents of the water-soluble potassium and calcium and magnesium in pericarps of the two cultivars respectively dropped in sequence at the same time.7. The multiple correlation coefficients between anyone and the other five of the contents of the total and the water-soluble potassium and calcium and magnesium in pericarps of the two cultivars were all significant. The majority of the partial correlation coefficients between any both of the contents of the total and the water-soluble potassium and calcium and magnesium in pericarps of the two cultivars respectively were the same.8. In2012, Sanyuehong litchi pericarp’s coloring was mainly influenced by the content of the total calcium in pericarp, and Baitangying litchi pericarp’s coloring was mainly influenced by the contents of the total and the water-soluble calcium. In2013, Sanyuehong litchi pericarp’s coloring was mainly influenced by the content of the water-soluble potassium in pericarp, and Baitangying litchi pericarp’s coloring was mainly influenced by the contents of the total and the water-soluble potassium in pericarp. So there were the same differences in the results of the canonical correlation analysis between the contents of potassium and calcium and magnesium in pericarps and the pericarp’s coloring of the two cultivars between two years.9. The exponential regression equations of the contents of the different pigments to part of the six indicators of the contents of potassium and calcium and magnesium in pericarp were significant, and the minority of the nonlinear correlation corresponding to these significant equations made no difference between the two cultivars. The contents of anthocyanin in pericarps of the two cultivars were positively correlated with the contents of the total calcium in their pericarps respectively, and the contents of chlorophyll in pericarps of the two cultivars were negatively correlated with the contents of the total calcium in their pericarps respectively during two years.In short, the contents of the pigments in pericarp changed depending on the changes of the contents of potassium and calcium and magnesium in pericarp, so the pericarp’s coloring of Sanyuehong litchi could be regulated through adjusting the contents of potassium and calcium and magnesium in its pericarp.