Categorization of Diverse Wheat Genotypes for Zinc Efficiency Based on Higher Yield and Uptake Efficiency

Abstract

Low zinc (Zn) availability in various agricultural soils including Vertisols adversely affects wheat production. The variations among the wheat genotypes to produce high grain yield and Zn uptake under low Zn supply were investigated to find out the Zn-efficient genotypes. Twenty-five different wheat genotypes were evaluated in the field with two levels of Zn, viz., low (no Zn fertilizer) and high (20 kg of Zn ha−1 applied as Zn sulfate heptahydrate (ZnSO4.7H2O) (21% Zn)) along with three foliar applications of Zn at ear initiation, flowering, and milking stage of wheat growth. Thousand grain weight, grain yield, grain Zn concentration, and Zn uptake of wheat genotypes differed significantly and increased due to Zn application. Among the genotypes, grain yield efficiency index (i.e., relative grain yield) varied from 85.0 to 98.6 and Zn uptake efficiency (i.e., relative grain Zn uptake) varied from 60.9 to 88.5. Considering grain yield efficiency index and Zn uptake efficiency index, the genotypes were categorized as efficient and responsive (JW-3211, GW-322, PBW-502, HD-2864, UP-2554, HI-8627, GW-190, SUJATHA-HI-627), efficient and non-responsive (HD-2932, LOK-1, PBW-175), inefficient and responsive (HD-4672, GW-366, UP-2628), and inefficient and non-responsive (HW-2004, WH-147, HI-1418, DL-803-3, PBW-343, HD-2733, UP-2565, JW-17, C-306, AKW-4627, HI-1500). The efficient and responsive genotypes are the most useful ones as they provide higher yield under low Zn supply and also respond to Zn fertilizer application. The inefficient and responsive genotypes may be utilized by the plant breeders to identify the responsive traits for their incorporation in modifying the efficient and non-responsive genotypes.