Morphological, Physiological and Molecular Markers for the Adaptation of Wheat in Drought Condition
Junaid Iqbal *
Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan.
*Author to whom correspondence should be addressed.
Abstract
Globally wheat is most important crop and mostly grows in rainfed areas. In cereal crops, wheat having highest protein content. In the abiotic stresses, mostly drought effects wheat productivity and at growth stages. According to climate change, frequency of drought increases in arid and semi-arid region because of water shortage. Drought effects all growth stages of wheat and more critical at flowering and grain filling stage. Losses of wheat productivity depend on the severity and duration of drought because of reducing in photosynthesis, stomata closure, metabolic activity decrease, oxidative stress increase and result in poor grain formation ultimately yield loss. Easy method to get yield from drought areas are to develop drought tolerance genotypes according to marks. Heritable variation required for the improvement, but heritability is low because of the genotypic and environmental interaction. Different genotypes of wheat behave different in drought. A comprehensive study helps us understanding of some important markers. Breeders can select well adaptive drought genotypes on the base of morphological markers (avoid leaf senescence, flag leaf, root system, grain development, stay green character, cuticular wax and stomata conductance.), physiological markers (abscisic acid (ABA), proline, chlorophyll content, jasmonic acid (JA) and cell stability) and molecular markers (Dreb 1, Dreb 2, Rht 8, TaMYB33, TaRZF38 etc.). Several genes which are doing job for drought stress tolerance and change the enzymes and proteins like, late embryogenesis abundant, rubisco, responsive to abscisic acid, glutathione-S-transferase, carbohydrates, helicase, and proline during drought stress. Drought stress alters some gene expression and cannot work properly due to the influence of environmental factors. Researchers used biotechnological tools to identify the specific genes for drought tolerances. These markers help us to identified drought tolerance genotypes for breeding program. This review paper covers morphological, physiological and molecular marks for the development of drought tolerance genotypes.
Keywords: Wheat, drought, tolerance, morphological, physiological, molecular, markers.