应用SPAD值预测小麦叶片叶绿素和氮含量的初步研究

2003～2004年以中筋小麦品种扬麦11号、WH510和徐州26为试验材料,研究不同生育时期(拔节、孕穗、抽穗)不同叶位叶片SPAD值变化特征及其与叶片叶绿素含量、全氮含量及NO3--N含量的关系,旨在为小麦上应用SPAD快速诊断施肥提供理论依据。结果表明,不同品种及不同叶位小麦叶片SPAD值明显不同;小麦叶片SPAD值与叶绿素含量之间的关系因品种和生育时期的不同而有明显差异,同一品种小麦不同叶位叶片SPAD值与叶绿素含量呈极显著正相关。小麦叶片SPAD值与全氮含量呈正相关,SPAD值高,全氮含量也高,可以用SPAD值估算全氮含量进行小麦氮素营养状况诊断,但同一品种不同叶位SPAD值与全氮含量的关系表现不一致,即用SPAD值来诊断小麦叶片氮含量时应选择完全展开并已进入功能盛期的叶片。小麦叶片SPAD值与NO3-N含量相关性不显著。

Primary Study on Application of SPAD Value to Estimate Chlorophyll and Nitrogen Content in Wheat Leaves

SPAD (Soil and Plant Analyzer Development) values at different growth stages and its relationship to chlorophyll, total nitrogen and NO_3~--N (content) in leaves of three medium-gluten wheat cultivars, namely Yangmai 11, WH510 and Xuzhou 26, were investigated. The results showed that SPAD values varied distinctly with cultivars. The relationship between SPAD value and chlorophyll (content) also (differed) among wheat cultivars. The SPAD values were positively correlated with chlorophyll (content) in the leaves of (different) plant positions for the same cultivar wheat. The SPAD value was also positively correlated with total nitrogen (content) in the leaves of (different) wheat cultivars. Therefore, it may be suggested that SPAD value can be used to (estimate) total nitrogen (content) to diagnose nitrogen status in wheat plants. Since the SPAD value of the (different) position leaves of the same cultivar wheat maybe not have obvious relationship with the total nitrogen (content). The SPAD value should be careful used to diagnose the nitrogen content of (different) part of the wheat leaf.