Comparative Study On Development And Quality Of Primary And Secondary Nuts Of Castanea Mollissima 'Zunhuaduanci'

Castanea mollissima BL.is a native tree species with high economic benefits in China.In recent years,the development of chestnut industry has been paid more and more attention by Chinese scholars.Secondary fruiting of Chinese chestnut contributes a lot to the yield of Chinese chestnut,but the yield of secondary fruiting of Chinese chestnut is low,sometimes showing poor quality.In this paper,the quality of primary and secondary fruits ofZunhuaduanci'with seconday fruiting characteristics was studied,and the difference of quality between secondary fruiting and primary fruits was compared.The dynamic changes of growth and nutritional indexes during the whole fruit development period of primary and secondary fruits were determined.The results were as follows:1.Starch accumulated less in primary and secondary fruits at young fiuit stage,soluble sugar began to accumulate gradually at 7 days after flowering,and starch and protein accumulated more rapidly after the appearance of kernels in fruits about 30 days after flowering.There are differences between primary fruit and secondary fruit in maturity period.The whole fiuit development period of primary fruit lasts about 90 days,and that of secondary fiuit lasts about 80 days.The difference is 10 days.During the two fruiting stages,fruit growth and nutrient accumulation were faster in the 7 days before fruit drop.2.The dynamic curve of total bract development was "S" type.The fresh weight of primary fruit and secondary fruit was 8.195g and 7.370g,the transverse diameter was 28.88 mm and 26.02 mm,the longitudinal diameter was 25.53 mm and 24.27 mm,and the lateral diameter was 18.87 mm and 18.23 mm,respectively.The fresh weight of primary and secondary fruit was 41.946 G and 40.622 g,respectively.The transverse diameter and longitudinal diameter of total bract basically accorded with "S" type.Growth curve characteristics.3.The starch content of nuts was 40.90%and 36.39%,the soluble sugar content of nuts was 15.89%and 15.74%,the protein content of fresh nuts was 18.04 mg/g and 28.06 mg/g,and the crude fat content of nuts was 2.01%and 2.14%,respectively.