Effect of Light Quality on Micropropagation and Some Morphological Properties of Cadaman Avimag (Prunus persica × P. davidiana ) Rootstock

Cadaman Avimag rootstock is widely used for almonds and peaches. The purpose of this study was to investigate the effect of light quality on micropropagation, and some morphological and physiological properties of this rootstock. Single node explants were cultured on WPM and MS media containing three levels of BA (0, 1 and 2 mg L-1) and three levels of NAA (0, 0.05 and 0.1 mg L-1). WPM medium containing 2 mg L-1 BA and 0.1 mg L-1 NAA was selected for different light quality treatments including fluorescent, red, and red+blue lights. Results showed that light quality had a significant effect on shoot proliferation, length and diameter, node number, shoot fresh and dry weights, leaf thickness, stomata number, and chlorophyll concentration. Red light resulted in higher shoot diameter, but crunchiness and lack of proper shoot growth. Moreover, red light produced the lowest amount of chlorophyll in the explants. Leaf thickness and its structural layers under the red light were the lowest among different treatments. Combined red+blue light in many factors resembled fluorescent light but induced more chlorophyll and a larger stomata size. The quality of light influenced the growth of this rootstock in vitro, and affected the stem and leaf vegetative traits.