Anatomical adaptations of Cynodon dactylon (L.) Pers., from the salt range Pakistan, to salinity stress. I. Root and stem anatomy.

Abstract

A naturally adapted salt tolerant population of Cynodon dactylon (L.) Pers., from highly saline soils of Uchhali Lake, the Salt Range, Pakistan was evaluated for root and stem anatomical modifications. A population from the normal (non-saline) soils of the Faisalabad region was also collected for comparison. Both populations were subjected to salt stress hydroponically. The salt treatments used were: control (0 mM salt), 50, 100, 150 and 200 mM NaCl in 0.5 strength Hoagland's nutrient solution. The Salt Range population showed specific root and stem anatomical adaptations for its better survival under harsh saline environments. Increased exodermis and sclerenchyma, endodermis, cortex and pith parenchyma in roots were critical for checking water loss and enhancing water storage capability. In stem, increased stem area (succulence), increased epidermis and sclerenchyma thicknesses (preventing water loss), increased cortex thickness (increasing water storage), and increased number and area of vascular tissue (increased water conduction) seemed to be crucial for its better survival under harsh saline environments.