超干对种子活力及水分热力学特性的影响  

EFFECT OF ULTRADRY ON SEED VIGOR AND SEED WATERTHERMODYNAMIC CHARACTERS

作　　者：伍贤进[1] 吕金海[2] 傅家瑞[1] 

机构地区：[1]中山大学生命科学学院,广东广州510275 [2]怀化师范高等专科学校生物系,湖南怀化418008

出　　处：《生物物理学报》2001年第3期579-586,共8页Acta Biophysica Sinica

基　　金：广东省自然科学基金 (980360);湖南省教育委员会青年骨干教师培养费资助

摘　　要：以耐干的菜心种子和不耐干的豇豆种子为材料 ,研究了超干对其活力和水分吸附等温线及热力学参数(ΔS、ΔH、ΔG)的影响。超干使豇豆种子活力下降 ,SOD、POD活性降低 ,膜结构受损 ,这些变化即发生在水分降低的干燥过程中又发生在超干状态下的贮藏过程中 ;菜心种子的活力和SOD ,POD的活性受超干的影响小 ,超干对细胞膜的轻微损伤可在萌发吸胀时得到修复。超干种子水分吸附等温线上区段1和区段2的含水量明显下降 ;超干种子除 -ΔS和 -ΔH在区段1略有所升高外 ,-ΔS、-ΔH在区段2和区段3和 -ΔG在各区段均有程度不同的下降 ;这些改变尤以豇豆种子较显著,说明豇豆种子的水分束缚能力低 ,较易失去水分吸附等温线上的强吸附水 ,继而引起大分子结构的改变 ,降低种子活力;而菜心种子则相反 ,能在超干状态下较好地保持酶的活性和细胞膜的结构 。Vigna Sesquipedalis seeds which were sensitive to ultradry and Brassica parachinensis seeds which were not sensitive to ultradry were used as experimental materials. Effect of ultradry on seed vigor, water sorption isotherms(WSI) and water thermodynamic parameters such as differential enthalpy(ΔS), differential entropy(ΔH),differential free energy(ΔG) were determined. Ultradrying treatments reduced V. Sesquipedalis seeds vigor and the activities of superoxide dismutase(SOD) and peroxidase(POD) and injured the cell membrane. Those harmful changes induced by ultradrying treatments occurred during ultradrying and subsequent storage under ultradry conditions. At the same time, ultradrying treatments did not induce any significant changes either seed vigor or the activities of SOD and POD of B. parachinensis seeds, and the slight damage of cell membrane induced by ultradrying treatments could be repaired during the seeds imbibition. After ultradrying treatments, the water contents of ultradried seeds in the WSI especially at the region 1 and region 2 were reduced. There were a slight increase of -ΔS and -ΔH at the region 1 of WSI, -ΔS,-ΔH at the region 2 and region 3 and -ΔG at the all regions of WSI were decreased to a various degree. In those changes the V. sesquipedalis seed is more significant. Those indicated that water binding ability of V. sesquipedalis seed was lower and it was easier to loss the essential binding water in the WSI, and then easier to induce structural changes of macromolecules. But for B. parachinensis seeds, the situation was the contrary, so it can keep the enzymatic activities and structure of cell membrane well, and was suitable for ultradry storage.

关 键 词：超干贮藏 菜心种子 豇豆种子 种子活力 水分吸附等温线 热力学参数 

分 类 号：S339.3[农业科学—作物遗传育种]