The effect of drought stress on morphological traits and proline values of five ‎medicinal species of Allium L. in Iran

To investigate the effect of drought stress on morphological traits and proline values seedling establishment in five species of Allium, a factorial experiment was conducted in a completely randomized design in greenhouse conditions at the Research Institute of Forests and Rangelands of Iran in 2019. The first factor was species in five levels (Allium longisepalum Bertol., A. rubellum M. Bieb., A. giganteum Regel, A. stipitatum Regel, A. vavilovii Popov & Vved.) and the second factor was drought stress at four levels (100% (control), 75%, 50% and 35% field capacity). The results showed that effect of drought stress was significant on root length, bulb length and diameter, bulb dry weight, bulb dry matter (%) and leaf proline content. The results of cluster analysis put A. rubellum and A. vavilovii with a larger and heavier bulb due to drought stress in one cluster and A. longisepalum, A. giganteum and A. stipitatum with longer root length in the second cluster. The results showed different responses of Allium species to drought stress, as in A. giganteum and A. longisepalum, which showed signs of wilting 24 and 20 days after severe drought stress (35% of field capacity), respectively, were the most tolerant species, which can be used for genetic modification or planting in green space.