Review on Maize (Zea mays L.) Breeding Methods for Improving Quality Protein and Others Nutritional Traits Lemi Yadesa

Abstract

Maize (Zea mays L.) is a member of the grass family Gramineae (Poaceae) and one of the oldest cultivated crops. To date, maize is widely cultivated in most parts of the world, over a wide range of environmental variables signifying its global and regional importance to millions of people who rely on the crop in pursuit of food security and livelihoods. Now a days, maize mixed with tef is also widely used in towns for making injera. To alleviate malnutrition, protein content can be increased to as high as 18% by increasing the prolamine (zein) fraction in maize endosperm, but unfortunately it consequently led to lysine and tryptophan deficiency. Since maize is a primary crop in the majority of farming systems and staple food of the rural population in much of the mid-altitude sub- humid agro-ecologies of Ethiopia, substituting the conventional maize (CM) with quality protein maize (QPM) can substantially improve the protein status and greatly reduce the malnutrition problem of resource-poor farmers and low-income people that depend on maize as their staple food. Recent evidence indicates that protein and amino acids play biological roles in protein and lipid synthesis, bone elongation, and the regulation of these and other processes necessary for linear growth. The intensities of lysine or tryptophan should be constantly restrained during the breeding process to sustain the protein quality in grain even when the op2op2 genotype is preserved. The maize kernel, like that of other cereal grains, includes pericarp (6%), endosperm (82%) and germ (12%).Molecular marker-assisted selection, often simply referred to as marker-assisted selection (MAS) offers such a possibility by adopting a wide range of novel approaches to improving the selection strategies in horticultural crop breeding. Appreciative concrete achievements in improving nutritional quality of food crops through conventional breeding efforts necessitate long-term investments, sustained research efforts and patience, besides continuing administrative, financial and scientific support. Further extensive use of MAS is also predictable with the enhancement of methods for marker analysis and identification of applicant genes for commercial traits. Appreciative concrete achievements in improving nutritional quality of food crops through conventional breeding efforts necessitate long-term investments, sustained research efforts and patience, besides continuing administrative, financial and scientific support. Time savings will be attained through MAS may be as significant as cost savings where there are reasonable markets for developed cultivars.

DOI: 10.7176/JBAH/11-21-02

Publication date: November 30^th 2021