磷钙锌对烟草生长及抗逆性影响的研究

Effect of P, Ca, Zn nutrition of growth of flue-cured tobacco andlts resistance to unfavorable environmental conditions

盆栽条件下研究了磷钙锌交互作用对烤烟（NC89）的生长、发育及抗旱、抗寒能力的影响及其机理。结果表明低磷水平下烟株的生长发育不良，增施磷肥可改善叶片的生长，叶片干重可提高41.8％，总生物重提高17．5％；但高磷水平下根／冠比值下降，养分吸收不平衡，烟株抗逆性反而下降。配施钙、锌可促进烟株根茎叶协调生长，极显著地提高根干重，根／冠比值适中。在逆境胁迫条件下，钙可提高细胞膜结构的稳定性，使细胞中电解质渗出物下降35％～42％；施锌能增加叶片细胞中SOD活性，因此减轻了烟株受活性氧自由基的伤害，表现为MDA含量明显降低。磷钙锌营养配合施用的交互作用能增加叶片中渗透调节物质的含量，烤烟的抗逆性提高。

Pot experiments were carried out to study the effects of P, Ca, Zn nutriti0n on growth, drought resistance andcold resistance of tobacco. Results show that under 1ow P level tobacco plants not grow well and root/shoot ratio washigh. Increase P nutrition improves leaf growth and dry weight was increased by 4l. 8 %. Total dry weight was in-creased by 17. 5 %. Under high P level leaf growth was slow and root weight and root/shoot were declined. Tobaccoplant abs0rbing other nutrition is not in balance and its resistance to un favorable environment conditions was also re-duced. Applying Ca and Zn can promote root growth and stem and leaf expanding. Ca can increase the stabi1ity 0f cellmembrane. Zn can strengthen superoxide dismutase (SOD)activity and mitigate the injury 0f free radical of activeoxygen(O2-) to plant, malondialdenyde (MDA)content was low. Therefore, P, Ca and Zn nutriti0n can als0 enhanceosmoregulaiton ability. The resistance to un favorable environmental c0nditions is significantly enhanced.