轮作及连作条件下荞麦功能叶片衰老特性的比较

Characteristics of Buckwheat's Leaf Senescence under Rotation and Continuous Cropping

为了探明轮作及连作条件下荞麦功能叶片的衰老特性,揭示叶片衰老机制和产量形成的内部生理机制,在连续4a定位试验的基础上,测定轮作及连作条件下荞麦开花后主茎功能叶片叶绿素质量分数、可溶性蛋白质量分数、保护酶SOD活性和膜质过氧化产物MDA、氧自由基积累量等生理指标。结果表明:荞麦开花后,随着衰老进程的推移,功能叶片的叶绿素质量分数、可溶性蛋白质量分数、SOD活性均呈先升高后下降趋势,且轮作显著高于连作;MDA和氧自由基积累量持续上升,且轮作低于连作;轮作荞麦籽粒产量较连作高出32.89%。综合分析说明,连作会加速荞麦功能叶片的衰老进程,而轮作在一定程度上能延缓功能叶片的衰老,维持叶片生理功能,对籽粒产量形成具有重要作用,故在荞麦生产上要合理地轮作倒茬。

To research the characteristics of buckwheat＇s functional leaf senescence under rotation and continuous cropping, and reveal the mechanism of leaf senescence and the internal physiological mechanism of yield formation, a series of experiments were conducted, on the basis of 4 years location test, to determine content of chlorophyll and soluble protein, activity of protective enzyme SOD （superoxide dismutase） and accumulation of MDA （malondialdehyde） and OFR （oxygen free radicals） of buckwheat＇s functional leaf under rotation and continuous cropping. The results showed that during the aging process after buckwheat＇s anthesis, the activity of SOD and the contents of chlorophyll and soluble protein showed the trend of first increased then decreased, and which were significantly higher in rotation treatment than in continuous cropping. The accumulation of MDA and OFR kept elevating, and which was lower in rotation than in continuous cropping. The grain yield of buckwheat under rotation was 32.89 % higher than that under continuous cropping. Comprehensive analysis showed that continuous cropping could accelerate the senescence of buckwheat＇s functional leaf, while rotation could relief functional leaf senescence to some extent, maintain the physiological function of leaves, and play an important role in yield formation. Therefore, reasonable rotation should be applied on the production of buckwheat.