GENETIC DIVERSITY FOR SALT TOLERANCE IN SPRING WHEAT IN GERMPLASM FROM PAKISTAN

Abstract

Wheat is the most important staple food crop of Pakistan where as it stand second in rank throughout the world after rice. During the last century, the losses occurred in genetic diversity are due to the introduction of varieties with high yield and the structural changes in wheat farming systems and fragmentation of meta-population structures of wheat landraces. This rehearsal commanded to the development of landrace meta-populations of wheat and the emergence of farmers' seed systems through which they retrieved and swapped diverse genetic material. Therefore, the wheat landrace is far from having a fixed unit, separate, and undeviating; diversity is related to the diversity of materials planted in the geographical area of the moment, to the level and pace of seed exchange among farmers. The abiotic stress such as salinity, drought, extreme temperatures, water logging, oxidative stress and toxic chemicals is severe intimidation of the natural state of the environment and agriculture as a whole. It is expected day after day an increase in the salinity of the arable land to have a global impact shock, within the next 25 years, leading to loss of land 30% to up to 50% by 2050. Thirty wheat varieties were grown in the field for three years on salt-affected soil under natural climatic conditions. The experimental design was a complete randomized block design with three replications. Three-year statistical analysis showed that the yield of combined grain harvest performance of varieties differed significantly. High potency salt increases the activities of antioxidant enzymes significantly; ascorbate peroxidase (APX) and guiacol peroxidase (GPX) in the salt-tolerant varieties and in the salt-tolerant varieties, and activity (SOD) and (CAT) were not infected. At the same time, under the condition of salinity activities of antioxidant enzymes such as guiacol peroxidase (GPX) catalase (CAT), and superoxide dismutase (SOD) in sensitive product was lower than the control, and with respect to (APX) activity there was a big difference. Under salt conditions the Salt tolerant varieties had gained more amounts of K+/Na+ ratio, K+ content, RWC, and sensitive ones recorded higher Na+ content and (CHL) at tillering stage. By resources of DNA fingerprinting techniques characterization of germplasm yield to genetic diversity quantitative estimate and specific germplasm identification. More diversity in germplasm more opportunities for superior results of risks from biotic and abiotic. The genetic diversity was also examined morphologically, biochemically and at the molecular level to evaluate the elite varieties for future breeding programs using saline stress as a limiting factor.