[Method for estimating relative chlorophyll content in wheat leaves based on chlorophyll fluorescence parameters]

Chlorophyll content is a physiological index widely used in the research of botany and agriculture. It is closely associated with leaf photosynthetic function. The current methods cannot simultaneously determine chlorophyll content and photosynthetic function and analyze their correlation. To solve this problem, we measured the SPAD value and chlorophyll fluorescence induction kinetic curve with 35 wheat varieties. We established a linear regression model using the fluorescence values of the fast chlorophyll fluorescence kinetic curve at different times, 33 common fluorescence parameters, and the correlation between the parameters and the SPAD values. We further verified the model using laboratory and field data. Our results showed that the linear model based on chlorophyll fluorescence parameter RC/CS_m could reliably predict the SPAD value of the leaves, which could be used to estimate the relative content of chlorophyll in wheat leaves under non-severe stress. The linear model enriched the method of nondestructive measurement of chlorophyll relative content in wheat, simplified the experimental flow, and achieved the simultaneous determination and analysis of wheat photosynthesis function and chlorophyll content.