不同马铃薯品种的氮利用效率及其分类研究

以7个马铃薯品种为供试材料,设置大田条件下施氮和不施氮2种处理,在对块茎产量和植株氮素吸收、利用评价的基础上,将不同氮效率品种马铃薯分类并解析了其差异机制。基于2016年施氮和不施氮条件下各品种马铃薯的平均产量,把不同氮效率品种马铃薯分为双高效型、低氮高效型、高氮高效型和双低效型。2017年选择双高效型、低氮高效型、双低效型的代表性品种,对各类型氮效率差异进一步解析表明,双高效型氮素利用效率显著高于另两个类型,氮素吸收效率则是双高效型、低氮高效型显著高于双低效型。不施氮条件下,双高效型马铃薯的干物质累积量在整个生育时期均显著高于另2个品种;双高效型、低氮高效型氮素累积速率在出苗后0～50d显著高于双低效型马铃薯。施氮条件下,双高效型马铃薯的干物质累积量显著高于另2个品种,与双低效型马铃薯相比,双高效型和低氮高效型产量的提高主要归因于它们前期较高的干物质累积;双高效型氮素累积速率显著高于双低效型、低氮高效型。双高效型马铃薯在各生育期的物质生产和氮素吸收能力强,从而有利于氮效率提升和产量的形成。该研究结果可为马铃薯氮高效品种筛选和利用提供理论支撑。

Classification of potato cultivars by their nitrogen use efficiency

Nitrogen efficiency of seven potato varieties was evaluated under field conditions with or without nitrogen application. Basing on tuber yield, plant nitrogen absorption and utilization of different potato cultivars, we classified nitrogen use efficiencies of seven potato varieties into four types: double high efficiency (DH), low nitrogen and high efficiency (LNH), high nitrogen and high efficiency (HNH), and double low efficiency (DL). Furthermore, one representative variety from DH, LNH and DL types respectively was selected to analyze the mechanism on the difference in nitrogen use efficiency, showing that nitrogen use efficiency of DH type was significantly higher than that of the other two types; the nitrogen absorption efficiency of DH and LNH was higher than that of DL type. Under no nitrogen application condition, the dry matter accumulation of DH type was significantly higher than that of the other two types at whole growth stage, and the cumulative rate of nitrogen in DH and LNH was significantly higher than that in DL type at 0-50 days after emergence. The dry matter accumulation of DH potato was significantly higher than that of the other two cultivars when nitrogen applied. Compared with DL type, the yield increase of DH and LNH was mainly attributed to the higher accumulation of dry matter at the early stage of potato. The nitrogen accumulation rate of DH was significantly higher than that of DL and LNH types under nitrogen fertilizer application. The greater nitrogen and dry matter accumulation in DH cultivars benefit yield formation and increase of nitrogen use efficiency. The results could provide theoretical support for high nitrogen use efficiency variety screening and its utilization.