High Altitude Plant Physiology Research Centre, Garhwal University, Srinagar-246174
* Present Address: Scientist-SC, Plant Physiology Branch, F. R. I. & Colleges, Dehradun 248006 (U.P.)
Variation in leaf morphology of one tropical (A. scoparia), two sub-temperate (A. vulgaris and A. parviflora) and one temperate (A. vestita) species of Artemisia were studied at 550 m, 1364 m, 2576 m and 3600 m altitudes in Garhwal Himalaya. The study reveals that the rate of leaf emergence was higher in A. scoparia, low in A. parviflora and the lowest in the other two species. Leaf emergence was considerably delayed at higher altitudes and the effect of altitude was prominent in A. scoparia and A. parviflora.
Leaf length and width invariably increased with increasing altitude and the effect became prominent within two months of the acclimatization of seedlings at these altitudes. The increase in length and width at 3600 m altitude was prominent in sub-temperate species. Leaves of all species of Artemisia showed heteroblastic development and the magnitude of hetaroblastteity varied from one altitude to another. The leaf length/width ratio was maximum at higher altitude and minimum at lowest altitude indicating variations in hetroblasticity along an altitudinal gradient. The magnitude of hetroblastieity was more marked in tropical species than in other three species. The results indicate that the diversity in leaf form was influenced significantly by the factors prevailing in the alpine zone.
