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顽拗型种子通常不能干燥到较低含水量或贮藏较长时间而不受伤害。导致这一问题的生化机制因属不同甚至同一属中的种不同而异。笔者测定了栎属、槭属和七叶树属顽拗型种子在室温下贮藏或干燥过程中的生化变化。虽然贮藏脂肪组成的变化是不确定的,但膜脂肪和蛋白质的结构以及蔗糖含量发生了变化。用两份白橡树种子在室温下贮藏12 d的实验表明,脱水样品的蔗糖含量发生很大变化,而保持水分的样品中蔗糖含量变化很小。因此,保持水分种子的蔗糖用于正常的生长和发育,而干燥种子的蔗糖则用作糖保护剂。尽管如此,蔗糖的存在也许能保护干燥橡实的细胞膜不致破裂,但蔗糖不能保持橡实的生活力。
Recalcitrant seeds are usually not dried to lower water content or stored for a longer period of time without injury. The biochemical mechanisms that lead to this problem vary from one genus to another and even from the same genus. The authors determined the biochemical changes of recalcitrant seeds of Quercus, Acer and Aesculus at room temperature during storage or drying. Although changes in the composition of stored fat are uncertain, the structure of membrane fat and protein, and sucrose content, have changed. Experiments with two white oak seeds stored at room temperature for 12 days showed that the sucrose content of the dehydrated sample varied greatly, while the sucrose content of the sample that retained moisture varied little. Therefore, sucrose, which retains moisture seeds, is used for normal growth and development, while dry seed, sucrose, acts as a sugar protectant. In spite of this, the presence of sucrose may protect the dried oak cell membrane from rupture, but sucrose does not maintain its viability.