Integrated structural and physiological adaptations of Buffel grass (Cenchrus ciliaris) to aridity gradients

Cenchrus ciliaris (Buffel grass) is a perennial, drought tolerant grass usually colonizes tropical and subtropical areas of the world. It grows for forages and fodder. The selected habitats were classified based on soil depth and Budekyo lettau dryness ratio (8.4-30.49) as least dry habitats NeW (Neela Wahn) and SoV (Soon valley), moderately dry habitats (KKr (Kallar kahar) and NpT (Noorpur Thal), severely dry habitats PaK (PakAnna), and Cho (Cholistan desert). The different ecotypes of Cenchrus ciliaris were evaluated for adaptability potential through morpho- physiological and anatomical attributes under water stress in relation to soil physico-chemical and environmental attributes. Root, shoot and leaf growth was significantly reduced in habitats with a greater dryness ratio such as Cholistan (Cho). The physiological attributes of pigment contents, ionic contents, and antioxidant activities were suppressed with increasing dryness ratio NpT, PaK and Cho. Among root anatomical attributes such as enhanced epidermal thickness, sclerified metaxylem vessels and large pith area was significantly higher in populations of dry land (Pak and Cho). The leaf anatomical attributes showed significant variations including intensive sclerification around the epidermis, cortical and vascular region, small metaxylem vessels that help them to conserve more water under water stress. The morpho-physiological and anatomical modifications provide better resilience for the movement of water and solutes and prevent water loss. These changes also provide mechanical strength for better survival under water stress.