三个类型桃及其杂种后代糖酸含量的差异

 以早星×早露蟠桃和94-1-40×早红2号两个杂种后代群体为试材，研究了果实糖、酸性状遗传与果形（扁平/圆形）、果皮毛有无（普通桃/油桃）、果肉颜色（白肉/黄肉）等质量性状的关系。桃果实的可溶性糖主要是蔗糖，占总可溶性糖的60%以上，其次是葡萄糖、果糖和山梨糖醇。桃果实的有机酸主要是苹果酸、柠檬酸和奎宁酸，莽草酸含量很低，仅占总酸含量的约0.3 %。在蟠桃群体中蔗糖、总糖、可溶性固形物的含量均显著高于普通桃群体，而葡萄糖、果糖、柠檬酸和莽草酸含量在蟠桃和普通桃后代间不存在显著差异。不同年份间苹果酸和奎宁酸含量在蟠桃和普通桃后代间存在差异。油桃后代的苹果酸、总酸平均含量显著高于普通桃后代，其柠檬酸、奎宁酸、莽草酸平均含量与普通桃后代间不存在显著差异。2005年油桃后代总糖、可溶性固形物及各可溶性糖组分含量均显著高于普通桃，2004年仅山梨醇含量显著高于普通桃后代。两年的结果均表明，总糖、可溶性固形物、总酸及各种糖酸组分在黄肉桃和白肉桃之间不存在显著差异，与吴本宏2003年的报道一致。

Differences of Sugar and Acid Contents Among Peach, Flat Peach, Nectarine and Their Progeny Populations

Sugar and acid contents were determined in two progeny populations (Early Star×Zaolupantao and 94-1-40×Early Red Ⅱ) in 2004 and 2005 in order to study the relationship of fruit shape (flat peach/peach), hairs on fruit epidermis (peach/nectarine) and flesh color (white / yellow ) with sugar and acid contents. Sucrose is predominant at maturity, followed by reducing sugars (glucose and fructose) and in smaller amounts by sorbitol. The main acids are malic acid, citric acid and quinic acid, while shikimic acid accounts for 0.3% of total acids. Sucrose, total sugar and soluble solids contents were significantly higher in flat peaches than peaches, while no significant difference was found in glucose, fructose, citric acid and shikimic acid contents between flat peaches and peaches. The difference in malic acid and quinic acid contents between flat peaches and peaches varied with year. Nectarines had significant higher malic acid and total acid contents than peaches, and did not show significant difference in citric acid,quinic acid and shikimic acid contents with peaches. Glucose, total sugar and soluble solids contents were significantly higher in nectarines than peaches in 2005, so was sorbitol contents in 2004. There were no significant difference in sugars, soluble solids and acids contents between white-flesh and yellow-flesh genotypes.