马铃薯不同品种淀粉积累生理基础研究───品种淀粉含量与叶部氮磷钾浓度的关系

本试验以高淀粉品种晋薯２号、中淀粉品种内薯３号、低淀粉品种紫花白为材料，对不同生育时期叶片及叶柄的全氮、全磷、全钾量进行了测定分析．其结果：同一品种内，随生育时期的推移，叶片和叶柄的氮、磷、钾含量均逐渐下降；各品种氮、磷在叶片中的含量始终高于叶柄，而钾在叶片中的含量则始终低于叶柄；不同品种叶片和叶柄氮、磷、钾含量变化与品种的淀粉含量呈正相关。生育中后期相关更显著，而叶柄氮、磷、钾含量与品种淀扮含量达到了显著正相关．因此，生育中后期叶柄的氮、磷、钾的含量是衡量马铃薯品种淀粉含量高低的重要生理指标，可做为马铃薯高淀粉育种早期选择和品质预测的科学依据．

STUDY ON THE PHYSIOLOGICAL BASIS OF STARCH ACCUMULATION IN DIFFERENT VARIETIES OF POTATO──THE RELATIONSHIP BETWEEN STARCH CONTENTAND N P K CONCENTRATIONS IN LEAF

Using the Jinshu 2 (a high starch contcnt variety),Neishu 3(a medium starch content variety) and Zihuabai(a low starch content variety)as the experimental material, we determincdand analyscd the content or nitrogen, phosphorus and potassium in leaf and leafstalk at different growth stage. The contents of N, K and P in leaf and leafstalk or the same variety decrease gradually with its growth. The contents of N and P in leaf arc always higher than thosein leafstalk, but the content or K in leaf is always lower than that in leafsalk. The starch content in dirfcrcnt varictics corrclatcs positivcly with the N, P and K contents in lear andlcafstalk, and the corrclation coecficicnt is higher in the middle and later growth period thanthat in the former stage. The starch content corrclates significantly with the N, P and K content in leafstalk. Thcrcfore, the N, P and K content in leafstalk is an important physiologicalindex for the measuring of s!arch content in diffcrcnt varietics, and can be used as a scientificbasis for the early sclcction and quality prophecy or the high starch content potato variety.