【摘要】 研究表明，旱育秧苗首先强化育根，前期根冠比大于水秧苗，后期单位株高干物重比水秧苗高，具有墩实壮秧特征。旱秧苗可溶性糖、淀粉、全氮、蛋白氮、非蛋白氮含量均比水秧苗高，ＮＲＡ是水秧苗的５．１２～６．１８倍；特别是在旱秧苗茎鞘中含较多营养物质，可溶性糖、淀粉、非蛋白氮、硝态氮含量分别比水秧苗高３７．７６％、１８．８２％、４３．３８％和３０．１倍，这既利于抵抗逆境，又为栽后早发快发奠定了物质基础。旱秧苗ＡＴＰａｓｅ活性比水秧苗高４．６１％～９４．３４％；旱秧苗抗逆保护酶ＳＯＤ、ＣＡＴ分别比水秧苗高６．２５％～３１．８２％、１．３２～１．５０倍；逆境物质ＭＤＡ含量比水秧苗低１６．９８％～２３．９７％，脯氨酸含量是水秧的２．２９～４．０８倍。旱秧苗对水分反应灵敏，叶片易萎蔫，但离体叶片在临界萎蔫后，失水速率降低，低于水秧苗３３．２６％，吸水能力增强，吸水速率比水秧苗高１３．０９％。由此可见，旱秧苗在逐渐适应旱育环境的过程中，形成了抗旱生理机制，具有抗旱能力强的生理特性。这种抗旱生理特性既是旱育秧苗适应旱育环境的体现，也是旱育秧苗具有增产效应的生理基础。更多还原

【Abstract】 Rice dry nursery seedlings (DNS) firstly strengthened the growth of root system, R/T of DNS was higher than that of moist nursery seedlings (MNS) before 3. 5-leaf stage. Dry matter weight (g) per cm plant height of DNS was higher than that of MNS after 3. 5-leaf stage. DNS had characteristics of stocky seedlings. The contents of soluble sugar, starch, total N, protein-N and non-protein N in DNS were higher than that in MNS. NRA of DNS was 4. 12-5. 18 times higher than that of MNS; content of NOR-N in the stem &. sheath of DNS was 30. 1 times higher than that of MNS. The activity of ATPase in DNS was 4. 61%~94.34% higher than that in MNS. The activities of SOD and CAT in DNS were 6.25% ~31. 82% and 132. 00%-150% higher than that in MNS respectively. Content of MDA in DNS was 16. 98%~23. 97% higher than that in MNS. Content of proline in DNS was 2. 29-4. 08 times higher than that in MNS. DNS was more sensitive to wilt than MNS at water stress. But the loss of water rate of isolated leaves of DNS decreased in temporary wilting time, and was 33. 2600 lower than that of MNS. So DNS had physiological mechanisms of drought resistance while DNS was adapted to the environment of dry nursery. The physiological characteristic of drought resistance of DNS was the physiological base of growth superiority of DNS after transplanting.更多还原