Application of novel image base estimation of invisible leaf injuries in relation to morphological and photosynthetic changes of Phaseolus vulgaris L. exposed to tropospheric ozone

摘要

This study aimed to evaluate the degree of Phaseolus vulgaris L. (bean) leaf tissue injury caused byudtropospheric ozone. To validate O3 symptoms at the microscopic level, Evans blue staining together withudan image processing method for the removal of distortions and calculation of dead leaf areas was applied.udNet photosynthetic rate (PN), stomatal conductance (gs) and intercellular CO2 concentration (Ci) wereuddetermined to evaluate leaf physiological responses to ozone. It was found that both resistant andudsensitive varieties of bean were damaged by ozone; however, the size of necrotic and partially destroyedudleaf area in the sensitive genotype (S156) was bigger (1.18%, 2.18%) than in the resistant genotype (R123),udi.e. 0.02% and 0.50%. Values of net photosynthetic rates were lower in the sensitive genotype in ambientudair conditions, than in the resistant genotype in ambient air conditions. We further found that there wasuda correlation between physiological and anatomical injuries; net photosynthetic rate (PN) was negativelyudcorrelated with percentage of necrotic area of both genotypes, while stomatal conductance (gs), intercellularudCO2 concentration (Ci) were positively correlated with percentage of necrotic tissue of both genotypes. Moreover, visible injures in both genotypes were positively correlated with percentage of anatomical injures. In conclusion, the presented combinations of morphological, anatomical and physiological markers allowed differential diagnosis of ozone injury.