MODIFICATION IN FAMILY CYPERACEAE FOR ABIOTIC STRESS TOLERANCE

Abstract

Cyperaceae found in various ecotypes of Pakistan as well as worldwide regions. Present study is based on some structural modification in root and stem anatomy of some species of Cyperaceae for abiotic stress tolerance. Members of Cyperaceae are adapted to a diversity of habitats in Pakistan, such as arid and semi-arid regions (Cyperus arenarius, C. rotundus), aquatic wetlands (Scripus spp. and Fimbristylis spp.) and sub-mountainous cooler regions salt range (Carex spp.). Cyperus alternifolia is the widely cultivated species in Pakistan as ornamental. All the studied species showed some specific structural adaptations to withstand environmental hazards. In the anatomical structure, some species (Cyperus arenarius) showed intensive sclerification (1.5 µm) in the cortical region of root as compared to other species, as well as in the vascular region, tightly-packed cortical parenchyma, maximum Aerenchyma cell area (12-15 µm²) in root recorded in Cyperus alternifolia and Cyperus compressus species. While in the stem anatomy Carex fedia showed intensive sclerenchyma (2.5 µm), cortical thickness and cell area, epidermal thickness almost equal in all species in stem anatomy. These modifications are important not only for minimizing water loss through roots but also for water conservation in harsh environmental condition. Halophytic/salt tolerant species are equipped with intensive aerenchyma for gaseous exchange in waterlogged condition and cortical region with well-developed sclerenchyma that conserve water. In addition, stellate cells are also recorded. These help in water conservation, salt dilution and salt transport.