Carbon nutrition differences between on-season and off-season longan in flowering

Flower bud differentition is the most critical stage of fruit yield formation, as well as a complicated carbon transfer process. It is very important to understand the changes of carbon during longan flower bud differentition process,therefore to adopt suitable planting measures and control flowering time. This study focused on the changes of sugar and starch content about on-season and off-season longan in the process of flowering. The results showed that the accumulation and transformation of carbon differed between on-season and off-season longan, sugar and starch content of on-season longan were decreasing at stage of buds physiological differentiation except leaf bud starch content, while the off-season longan flower buds in late rose instead of fall. The total sugar content increased from 15.43 mg/g (-7 d) to 31.38 mg/g (7d), and starch content increased from 5.42 mg/g to 8.31 mg/g during this time, which may be relevant to external environment, or tree original metabolism be broken by potassium chlorate.