Influence Of Calcium On Fruit Cracking Of Jujube 'Huping' And Its Physiological Mechanism

Zizyphus Jujuba Mill.'Huping' was an experimental material in the study and handled with calcium preparations in different Growth period. Jujube and leaves were measured cell wall components ?pectin, cellulose?,cell wall degrading enzyme ?PG, CX?,protective enzymes ?SOD, POD, CAT? and other physiological indicators which was analyzed the influences and compared with the difference of normal fruit and cracking in different treatments. To understand the relationship between calcium and fruit cracking and physiological mechanisms. Discussion on the role of calcium as nutrient elements in the jujube fruit cracking. The optimal calcium preparations and spraying period was screened to reduce the rate of Jujube fruit cracking. The purpose of experiment is that provide a theoretical basis and practical guidance for prevention and Control of jujube fruit cracking.The conclusions was as follows:?1? First, the rate of Jujube fruit cracking both were reduced by treatment of three kinds of calcium preparation, especially Spraying CaCl₂ in the fruit enlargement.?2? Compared with CK handle the SOD, POD, CAT activity of jujube leaf?pulp?peel both were improved in different treatments, especially Spraying Calcium EDTA in the fruit enlargement. And the three enzymes activities of normal fruit processing were higher than cracking process. There was a significant negative correlation of Jujube fruit cracking rate and SOD?CAT activity, especially SOD activity in the peel which appear highly significant correlation and the value reach -0.637.?3? The cell wall enzyme activity of parts of jujube both were suppressed in different spraying period, especially Spraying CaCl₂ in the fruit enlargement. And normal fruit PG, CX activity were less than cracking process. There was a extremely significant positive correlation of Jujube fruit cracking rate and PG activity in the peel. The relationship between Jujube various parts of the cell wall active and cracking rate was closed.?4? Compared with CK handle the proto pectin content?total pectin content and cellulose content of jujube leaf?pulp?peel both were improved in different treatments, especially Spraying Calcium CaCl₂. And normal fruit proto pectin content?total pectin content and cellulose content were Significantly higher than cracking process. And that there was a extremely significant negative correlation of Jujube fruit cracking rate and total pectin content in the peel.?5? By the correlation analysis of jujube fruit cracking rate and the fruit physiological index, it is found that the correlation between cracking rate and pectin content and PG activity of peel is most obvious, reached extremely significant. So ultimately we selected inorganic calcium CaCl₂ treatment which is most obvious to reduce cracking rate and suitable period of spraying that Expanding stage to white stage.