1Islamic Azad University, Meibod Branch, Meibod, Iran
2Islamic Azad University, Qaemshahr Branch, Qaemshahr, Iran
3Islamic Azad University, Branch, Dezfoul, Iran
Drought is still limited in most crops is produced. Morphological and physiological knowledge to improve drought resistance under drought conditions created problems important is the fact each of these genetic relationships and processes associated with the exact amount of important plant and grain yield is unknown. The other hand, heritability of grain yield under water is reduced. Improve the performance of drought tolerant cultivars based on morphological and physiological components of plant modification as an important solution is proposed. One of the key predictions of climate change is that, in some regions, droughts are likely to increase in frequency and severity. This will have significant implications for the long-term viability of plant populations, especially where water availability plays a key role in delineating species ranges. However, while drought and overall aridity are known to be strong determinants of plant species distributions at the landscape level, much less is known about the ways in which plant populations respond to changes in drought regime, or the long-term impacts that extreme droughts have on plant community composition, structure, and function. While it is known that drought can cause significant re-structuring of plant communities, relatively few studies have quantified the environmental and biological factors that promote plant survivorship under acute moisture stress, especially in topoedaphically heterogeneous landscapes. The capacity for evolution to rescue plant populations faced with increasingly severe drought from extinction is also poorly understood. This places severe restrictions on our ability to predict the impacts of climate change on plant populations in many environments worldwide. In this paper a review Effects of climate change and Drought-stress on plant physiology.