Varietal difference in relationship between SPAD value and chlorophyll and nitrogen concentration in rice leaf

摘要

This experiment was conducted to determine the varietal differences in the relationships of chlorophyll and nitrogen concentration with leaf greenness value (SPAD value). We used two rice cultivars with different leaf colour type: Hwaseongbyeo has pale green leaves, and Gwanganbyeo has dark green leaves. SPAD value was correlated with chlorophyll a concentration significantly in both varieties, but not with chlorophyll b in Hwaseongbyeo. The correlation coefficients between SPAD value and nitrogenconcentration of rice flag leaves were highly significant. However, the regression analysis between SPAD value and nitrogen concentration of rice flag leaves showed different relation among varieties. The slope of the regression line in Gwanganbyeo was steeper than that in Hwaseongbyeo. In conclusion, SPAD value can be applied to estimate the chlorophyll a concentration without consideration of varietal differences. Chlorophyll b and nitrogen concentration in the leaf were regressed with the SPAD values, which varied according to varieties. This implies that the SPAD value can not be used directly to estimate chlorophyll b and nitrogen concentration without consideration of varietal differences.