Abstract:

【Objective】 The experiment aimed at study on the relationship between peanut pod dry matter accumulation and sucrose metabolism. 【Method】 With the seeds of normal peanut line 05D610 and its wrinkled mutant line 05D677 as material, the dynamic changes of pod dry weight (during 6-72 d after peg penetration), contents of soluble sugar, sucrose,fructose,glucose,starch, protein, and oil in seeds (during 6-72 d after peg penetration), and activities of sucrose-metabolizing enzymes (during 30-72 d after peg penetration) were examined. 【Result】 The period of 24-54 d after peg penetration was a rapid dry weight accumulation phase which determined the final dry weight, and pod dry weight accumulation rate of 05D610 was 2.4 times that of 05D677 in the same period. At harvest, dry weight of 05D610 and 05D677 were 2.06 g and 1.28 g, respectively, the difference between them was highly significant. In the period of 30-72 d after peg penetration, hexose/sucrose ratio and oil content of 05D610 seeds were always significantly higher than that of 05D677, while the protein content of 05D610 being always significantly lower than that of 05D677, and the starch content in seeds was not different significantly between 05D610 and 05D677. During the period of seed dry matter accumulation, the activity of sucrose synthase (SS) was significantly higher than that of sucrose phosphate synthase (SPS), which was the main enzyme on sucrose syntheses. SS activity was higher than acid invertase (AI) and neutral invertase (NI), which was also the main enzyme for direction of sucrose cleavage. In conclusion, SS is the main enzyme for sucrose metabolism at the stored matter accumulation stage of peanut seeds. SS (synthesis) activity in seeds showed slight difference between 05D610 and 05D677.SS (cleavage) activity of 05D610 was significantly lower than that of 05D677. SPS activity of 05D610 was significantly higher than that of 05D677. 【Conclusion】 The phase 24-54 d after peg penetration is more important for pod dry weight accumulation. SS (cleavage) is a key enzyme for organic matter accumulation. The difference in hexose/sucrose ratio, SPS activity, SS (cleavage) activity between 05D610 and 05D677 may be the dominant factor leading to their difference in dry weight accumulation rate of pod, pod dry weight and content of components in peanut seeds.

Key words: peanut, pod development, dry matter accumulation, sucrose metabolism