Srivastava, P.C.Rawat, Deepa2016-08-042016-08-042015-01http://krishikosh.egranth.ac.in/handle/1/70922Thesis-PhDUnder Zn deficient condition, NDR 359; a Zn-inefficient rice variety showed higher acidity while UP 262, a Zn-inefficient variety of wheat failed to do so. Under no Zn application, PD 16; a Zn efficient rice variety increased the number of root tips at 60 days after transplanting and root length, diameter, surface area and volume at 90 days after transplanting whereas NDR 359 decreased root length, number of tips and forks at 90 days after transplanting. Zinc efficient wheat variety, UP 2628, maintained higher surface area and number of root tips at 120 days after sowing. With application of 10 mg Zn kg-1 soil, the Zn-inefficient variety of rice; NDR 359 reported the highest increase (41.3 %) in grain yield over no Zn application while the increase in rest other three varieties of rice was statistically not significant. Among varieties of wheat, the Zn-efficient variety UP 2628 had the highest grain yield and least alue was noted in Zn-inefficient UP 262. Zinc efficient varieties of rice and wheat produced grains with higher Zn concentration as these varieties readily translocated Zn from the vegetative tissue to panicle/ear part. Application of 10 mg Zn kg-1 soil Zn increased the total uptake of Zn in rice and wheat varieties by 19.3 and 37.3 percent, respectively. Zinc efficient variety of rice; PS 5and PD 16 maintained higher Zn flux between 30 and 60 days as compared to Zn inefficient variety, NDR 359. In wheat varieties, the flux of Zn was higher during 60 and 90 days after sowing as compared to 30 to 60 days after sowing. During 60 to 90 days after sowing Zn efficient variety, UP 2628, maintained higher Zn flux as compared to 262 even in the absence of Zn application. Zn-efficient varieties of rice (PD 16, PS 5) and wheat (UP 2628) are needed to be explored for developing Zn efficient genotypes for sustainable grain production.enzinc, nutrient uptake, tissues, rice, wheats, sensitivityThesis