Life cycle and florogenesis of the Israeli native geophyte Allium aschersonianum

Abstract

The Israeli native species Allium aschersonianum, indigenous to the Jordan Valley and the Negev Desert, has recently shown promise as an ornamental crop. Study of the florogenesis of the plant and of the effects of temperature on its development revealed a thermoperiodic annual cycle of the monocarpic shoot. Initiation of leaf primordia in the renewal bulb begins during the growth of the parent plant. During summer, the bulb enters a long period of quiescence, when the apical meristem remains vegetative and latent. Temperature decrease leads to the transition of the apical meristem to the reproductive stage, and the differentiation of individual flowers in the reproductive meristem occurs during the plant growth and leaf elongation in October-November. In contrast to other species of the same subgenus Melanocrommyum, low temperatures are not required for leaf and floral stalk elongation and florogenesis. Summer storage of bulbs at 20 °C significantly promotes intrabulb flower initiation and differentiation.