Nondestructive evaluation of the photosynthetic properties of micropropagated plantlets by imaging photochemical reflectance index under low light intensity

The photochemical reflectance index (PRI) of micropropagated potato leaves was estimated nondestructively from outside the culture vessel using a PRI imaging system developed by the present group. The PRI was determined under low light intensity conditions after dark treatment and compared with the chlorophyll fluorescence parameter Fv/Fm, which denotes photosystem II maximum quantum yield. Short-term high-light treatment decreased Fv/Fm of the plantlets. Culture conditions such as temperature and sucrose concentration also affected Fv/Fm. A linear relationship between the PRI and Fv/Fm was observed in both cases of high-light treatment and different culture conditions, suggesting the potential of the PRI to be used as a substitute for Fv/Fm. PRI estimated from reflection images under low light intensity conditions may be used for rapid and noninvasive evaluation of photosynthetic properties of micropropagated plantlets in a similar manner to Fv/Fm.