Hybrid Breeding for MLN Resistance: Heterosis, Combining Ability, and Hybrid Prediction
Loading...
Date
2020
Authors
Nyaga, Christine
Gowda, Manje
Beyene, Yoseph
Murithi, Wilson T.
Burgueno, Juan
Toledo, Fernando
Makumbi, Dan
Olsen, Michael S.
Das, Biswanath
L. M., Suresh
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
Prior knowledge on heterosis and quantitative genetic parameters on maize lethal necrosis
(MLN) can help the breeders to develop numerous resistant or tolerant hybrids with optimum
resources. Our objectives were to (1) estimate the quantitative genetic parameters for MLN disease
severity, (2) investigate the e ciency of the prediction of hybrid performance based on parental per
se and general combining ability (GCA) e ects, and (3) examine the potential of hybrid prediction
for MLN resistance or tolerance based on markers. Fifty elite maize inbred lines were selected
based on their response to MLN under artificial inoculation. Crosses were made in a half diallel
mating design to produce 307 F1 hybrids. All hybrids were evaluated in MLN quarantine facility
in Naivasha, Kenya for two seasons under artificial inoculation. All 50 inbreds were genotyped
with genotyping-by-sequencing (GBS) SNPs. The phenotypic variation was significant for all traits
and the heritability was moderate to high. We observed that hybrids were superior to the mean
performance of the parents for disease severity (14.57%) and area under disease progress curve
(AUDPC) (14.9%). Correlations were significant and moderate between line per se and GCA; and mean
of parental value with hybrid performance for both disease severity and AUDPC value. Very low
and negative correlation was observed between parental lines marker based genetic distance and
heterosis. Nevertheless, the correlation of GCA e ects was very high with hybrid performance which
can suggests as a good predictor of MLN resistance. Genomic prediction of hybrid performance for
MLN is high for both traits. We therefore conclude that there is potential for prediction of hybrid
performance for MLN. Overall, the estimated quantitative genetic parameters suggest that through
targeted approach, it is possible to develop outstanding lines and hybrids for MLN resistance.
Description
A research article published in Plants
Keywords
maize lethal necrosis, combining ability, heterosis, genomic prediction, resistance
Citation
Plants vol 9, No. 468. 2020