MOLYBDENUM STRESS AFFECTS VIABILITY AND VIGOR OF WHEAT SEEDS

Abstract

Wheat (Triticum aestivum L.) cv. Sonalika was grown in refined sand at variable molybdenum (Mo) supply ranging from acute deficiency (0.00002 mg L⁻¹) to excess (10 mg L⁻¹). Deficiency as well as excess of Mo decreased significantly the biomass, grain yield, Mo content in leaves and seeds and activity of nitrate reductase in leaves. The effect of high (>0.02 mg L⁻¹) Mo was more marked than its deficiency on wheat. Low and excess Mo deteriorated the quality of grains by lowering the content of starch, sugars, protein, non-protein, and total nitrogen (N) as well as that of prolamin, glutelin, and globulin fractions of seed proteins and increasing the content of albumin and electrical conductivity (EC) of seed leachate. Molybdenum deficiency and excess both resulted in production of lightweight immature seeds, poor in vigor and germination potential. The post fertilization developmental stages required one tenth of the adequate Mo supply for normal bold seed production in wheat. The values of sufficiency and threshold of toxicity in leaves were 0.13 and 1.15 μ Mo g⁻¹ dry matter of wheat.

Acknowledgments