Trait-QTL-heritability of grain yield and other agronomic traits under low nitrogen conditions in bi-parental maize populations

Collins Kimutai 1, *, Manje Gowda 2 and Oliver Kiplagat 1

1 University of Eldoret, Public university in Kenya.
2 International Maize and wheat Improvement center (CIMMYT-KENYA).
 
Research Article
International Journal of Biological and Pharmaceutical Sciences Archive, 2021, 02(01), 096–116.
Article DOI: 10.53771/ijbpsa.2021.2.1.0072
Publication history: 
Received on 11 July 2021; revised on 14 August 2021; accepted on 16 August 2021
 
Abstract: 
Limited or low Nitrogen is a wanting abiotic stress in maize mainly in Sub-Sahara Africa, affecting yields and quality development of maize crop. As an approach to getting a breeding solution; mapping of QTLs and understanding the heritability factor can provide useful information and guide for breeders in developing low nitrogen resilient maize. QTL mapping which is a molecular breeding component forms an actual basis in estimation of genomic regions associated to the expression of quantitative traits, and how heritable are such traits. Conducting a selection for Low N-tolerance is challenging due to its complex nature with strong interaction between genotypes and environments; therefore, marker assisted breeding is key to improving such complex traits, but at the same time requires markers associated with the trait of interest. In this study, three bi-parental populations were subjected to either or both low and optimum N conditions to detect and determine the QTLs heritability for grain yield and other agronomic traits. Essential to the study; genotype by environmental interaction, significance and heritability was examined for each population with most traits expressing low (<0.2) and moderate to high heritabilities (0.3>). These QTLs with high heritabilities across environments will be of great value for rapid introgression into maize populations using marker assisted selection approach. The study was a preliminary and therefore require further validation on heritability and fine mapping for them to be useful in MAS.
 
Keywords: 
Heritability; QTL Mapping; Grain yield; Low nitrogen conditions
 
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