GENERATION MEAN ANALYSIS FOR DIFFERENT MORPHO-PHYSIOLOGICAL PARAMETERS OF MAIZE SEEDLING UNDER DIFFERENT REGIMES OF WATER

Abstract

Maize being the leading cereal grain crop is widely used throughout the world including Pakistan. About thirty-three percent of world's arable land experiences a deficiency of water and the greatest harvest yields are frequently decreased by dry spell. The current research was considered to examine the genetic traits governing the drought tolerance of morphological and physiological parameters during the seedling stage in maize. The breeding stock consisted of two parental lines, YP-12 and US-17 with variable traits concerning their ability to bear water shortage and their succeeding generations F1 and F2 along with back crosses (BC1 and BC2). The combined analysis of variance for all traits yielded significant differences among generations and water treatments suggesting the presence of a wide range of genetic variability. Relative water contents, leaf water potential, osmotic potential and turgor potential decreased under water stress environment. All morphological parameters like root and shoot length, fresh root and shoot weight and dry root and shoot weight exhibited a decrease in response to water stress. Dry shoot weight, turgor potential and osmotic potential under water stress have additive nature suggesting that early selection based on one of these traits may also complement the other resulting in the development of better-yielding maize material for stress tolerance. Further, root characters such as root length, fresh and dry weight can play a crucial role in efficiently evaluating the maize genotypes to drought stress during the seedling stage. Key words: Epistasis, Dominance, Genetic basis, Maize, Drought tolerance