Action of o2 modifiers for endosperm modification and amino acids on o2 maize

Abstract

QPM (Quality Protein Maize) with o2 gene alone cause to improve tryptophan and lysine content but negative correlation with normal maize phenotype. QPM lines reported low yield, susceptible to ear rot disease and storage pest due to insignificant variation in kernel for modification. Also amino acid imbalance in QPM lines with o2 genes which could not supplement daily intake of protein supplements. This malnutrition deficiency leads to disorders like improper growth, kwashiorkor and Pellegra. To mitigate this problem, breeding of QPM with o2 modifiers for endosperm modification and amino acid modification was focussed and found to be effective with sufficient nutrient supplements. Endosperm modifiers act on 27-kDa γ-zein to modify into vitreous endosperm which could be resistance to ear rot disease. Further amino acid modifiers act on maintenance in balancing amino acid content of both zein and non zein protein. By the action of these o2 and o2 modifiers, modern Quality Protein Maize (QPM) developed with increased lysine and tryptophan and also with good agronomic traits.