Retour au sommaireVAILLANT V., BADE P., CONSTANT C. 2005. Photoperiod affects the growth and development of yam plantlets obtained by in vitro propagation. Biologia Plantarum 49(3): 355-359.
Abstract :
The effects of photoperiod on the development of in vitro grown plantlets of yam (Dioscorea alata L.), were investigated.
Plantlets were transplanted into pots, acclimatizated until they reached vegetative stages V-1 (3 leaves) or V-2 (8 leaves), and then grown under 12-h or 16-h photoperiod.
The formation and development of underground tubers was only induced under 12-h photoperiod.
Tuber initiation was not related to the initial vegetative stage of plants, and the tubers were visible at about 18 - 24 d. On the contrary, a 16-h photoperiod inhibited tuber formation and stimulated vine and leaf growth.
The total dry matter production and the number of leaves per plant of V-1 stage plants were 50 and 30 % lower respectively, after 44 d under 12-h compared to 16-h photoperiod. These parameters were not influenced by photoperiod in V-2 stage plants.
Consequently, the effect of 12-h photoperiod on dry matter of V-1 plants was attributed to a source limitation related to the early initiation of tuberization.
The transfer of plants grown under 12-h to 16-h photoperiod stopped tuber growth and starch accumulation.
On the other hand, it stimulated the shoots and the roots to grow.