番茄叶片叶绿素含量光谱估算模型

以番茄品种“金粉2号”为试验材料，在玻璃温室内设置3种土壤水分胁迫水平，以正常灌溉为对照，于2013年3—7月和8—12月两个生长季对番茄进行全生育期持续处理。采用便携式地物光谱仪测定各生育期番茄冠层的光谱反射率，同步测定叶片总叶绿素和叶绿素a含量，并基于3—7月数据计算常见高光谱植被指数，分别建立番茄叶片叶绿素总量和叶绿素a估算模型，用8一12月生长季的试验数据对模拟精度进行检验。结果表明：（1）水分胁迫对番茄叶片总叶绿素、叶绿素a含量和番茄冠层光谱反射率产生明显影响，水分胁迫越严重，叶绿素总量和叶绿素a含量均越低，番茄冠层光谱反射率也越低；（2）随着生育期的推进，番茄总叶绿素和叶绿素a含量均持续增加，而冠层光谱反射率在红光和蓝光波段的反射率逐渐减少；（3）4种估算模型中R670模型的决定系数（R。）最高，效果最佳（P〈0．01），番茄叶片总叶绿素和叶绿素a最佳估算模型分别为：C_chl（a＋b）=44．83R670＋_670＋7.36，C_chl=39．92R_670＋5．12，均根方误差分别为0．45、0．42mg·g^-1，表明利用高光谱数据估算番茄叶片的叶绿素含量可行。

Chlorophyll Content of Tomato Leaf Estimate Model Under Different Water Stress Treatments Based on Hyperspectral

In order to establish the estimate model of chlorophyll （ a ＋ b） and chlorophyll a of tomato leaf, tomato variety Jinfen 2 was taken as test material, four soil water treatments were conducted in all growth stages in greenhouse of Nanjing University of Information Science ＆ Technology from March to July,2013, and another repeat experiment was conducted from August to December,2013. The experimental data during March to July was used to establish estimate model of chlorophyll （ a ＋ b） and chlorophyll a, while another one was used to test the model. The soil water content was divided into four levels ： control （75% to 80% of field water holding capacity）, light drought treatment （ LT, 55% to 60% of field water holding capacity） ,moderate drought treatment（ MT,40% to 85% of field water holding capacity） , and severe drought treatment （ST,25 % to 30% of field water holding capacity）. Tomato canopy spectral reflectance of each growth period under each water treatments were determined by using ASD portable spectroradiometer（US） ,at the same time, chlorophyll （ a ＋ b） and chlorophyll a content of leaf were also determined. Then by fitting a variety of common hyperspectral vegetation index models between canopy reflectance and chlorophyll relationships, four models for chlorophyll（ a ＋ b） and chlorophyll a content of tomato were established. The results showed that water stresscaused chlorophyll （ a ＋ b ）, chlorophyll a and canopy spectral reflectance significantly decrease, moreover, their decrease trend increased with the increased degree of water stress in all the growth stages. With the advancing of tomato growth stage, both chlorophyll（ a ＋ b） and chlorophyll a were increasing, while the canopy spectral reflectance decreased in red and blue band wavelength. By comparing the effect of four models, R670 model was the best for chlorophyll（ a ＋ b ） and chlorophyll a content estimate. Therefore, chlorophyll （ a ＋ b ） and chlorophyll a content estimat