AUTHOR=Bankole Folusho , Menkir Abebe , Olaoye Gbadebo , Crossa Jose , Hearne Sarah , Unachukwu Nnanna , Gedil Melaku 

TITLE=Genetic Gains in Yield and Yield Related Traits under Drought Stress and Favorable Environments in a Maize Population Improved Using Marker Assisted Recurrent Selection

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00808

DOI=10.3389/fpls.2017.00808

ISSN=1664-462X

ABSTRACT=<p>The objective of marker assisted recurrent selection (MARS) is to increase the frequency of favorable marker alleles in a population before inbred line extraction. This approach was used to improve drought tolerance and grain yield (GY) in a biparental cross of two elite drought tolerant lines. The testcrosses of randomly selected 50 S<sub>1</sub> lines from each of the three selection cycles (C<sub>0</sub>, C<sub>1</sub>, C<sub>2</sub>) of the MARS population, parental testcrosses and the cross between the two parents (F<sub>1</sub>) were evaluated under drought stress (DS) and well watered (WW) well as under rainfed conditions to determine genetic gains in GY and other agronomic traits. Also, the S<sub>1</sub> lines derived from each selection types were genotyped with single nucleotide polymorphism (SNP) markers. Testcrosses derived from C<sub>2</sub> produced significantly higher grain field under DS than those derived from C<sub>0</sub> with a relative genetic gain of 7% per cycle. Also, the testcrosses of S<sub>1</sub> lines from C<sub>2</sub> showed an average genetic gain of 1% per cycle under WW condition and 3% per cycle under rainfed condition. Molecular analysis revealed that the frequency of favorable marker alleles increased from 0.510 at C<sub>0</sub> to 0.515 at C<sub>2</sub>, while the effective number of alleles (N<sub>e</sub>) per locus decreased from C<sub>0</sub> (1.93) to C<sub>2</sub> (1.87). Our results underscore the effectiveness of MARS for improvement of GY under DS condition.</p>