Life Cycle, Flower Initiation, and Propagation of the Desert Geophyte Allium rothii

Abstract

Analyses of life cycle, morphogenesis of the monocarpic shoot, and propagation have been carried out on Allium rothii, a desert geophyte from the Western Irano-Turanian region. Plants from a natural population in the Negev Desert highlands were examined during a 2-yr study. The bulb of A. rothii is a temporary organ that is completely replaced by a renewal bulb within 2 yr. The ephemeroid root system is annual, superficial, and adapted for effective absorption during short periods of moist soil. Seeds germinate best in January and February at temperatures between 5⚬C and 15⚬C; germination is not affected by light. The germination process and stages of the life cycle are characterized. The synaptospermic mechanism assures protection of the mature seeds against insects and germination under more favorable conditions in depressions and near shrubs. Intrabulb development was studied by SEM. Five leaf primordia form in apical meristem in June-September; in October the apical meristem becomes reproductive. Anthers and perianth lobes appear in January, while the gynoecium is formed before flowering at the end of February.