龙眼、荔枝叶片膜脂脂肪酸与耐寒性的研究

龙眼、荔枝耐寒性不同的品种，其叶片膜脂脂肪酸组分含量不同．耐寒性较强的品种叶片不饱和脂肪酸含量较高，龙眼品种红核子等为８１．７４％—８３．３７％，荔枝品种陈紫、桂林、宋家香和乌叶为７７．０％—７９．６７％，比耐寒性弱的品种高；不饱和指数（ＩＵＦＡ）亦大，龙眼（红核子、油潭本）、荔枝（陈紫、桂林、宋家香和乌叶）分别为２２１．１２—２２６．３４和２１２．９７—２２１．４５．不饱和脂肪酸中，亚麻酸／（亚油酸＋油酸）的比值差异显著，龙眼耐寒性较强的红核子等为２．４８３３—２．６７６６，耐寒性中等的赤壳硬枝等为１．３０５５—２．１２８３，耐寒性较弱的乌龙岭等为０．９０８４—１．０５７８；荔枝耐寒性较强的陈紫等品种为４．４８３３—４．６４６４，耐寒性中等的糯米糍等品种为３．２３７９—３．８２１３，耐寒性较弱的兰竹等品种为２．６１５３—２．９６１４．这可作为鉴别品种间耐寒性差异的有效指标

Relationship between Membrane Fatty Acid in Leavesand Cold Resistance of Longan and Litchi

Cultivars with different cold resistance of both longan and litchi differred in their contents of membrane fatty acid composition in leaves. Compared with poor cold resistant cultivars, high cold resistant cultivars had not only higher contents of unsaturated fatty acid in leaves, i.e. 81.74% - 83.37% in longan and 77.03% - 79.67% in litchi, but also larger indexes of unsaturated fatty acid (IUFA), i.e. 221.12 - 226.34 in longan and 212.97 - 221.45 in litchi.Especially, the ratios of linolenic acid to linoleic acid and oleic acid were significantly different among the content of unsaturated fatty acids, which were 2.4436 - 2.6766, 1.3055 - 2.1283 and 0.9084 - 1.0578 respectively in high cold resistant cultivars (such as Honghezi), intermediate cold resistant cultivars (Chike Yingzhi etc.) and low cold resistant cultivars (Wulongling and so on) in longan, and 4.4833 - 4.6464, 3.2379 - 3.8213 and 2.6153 - 2.9614 respectively in high cold resistanat cultivars (Chengzi etc.), intermediate cold resistant cultivars (such as Ruomizhi etc.) and low cold resistant cultivars (Langzu and so on) in litchi, so it could effectively be used as a way to determine the cold resistance of cultivars.