Genetic distance among doubled haploid maize lines and their testcross performance under drought stress and non-stress conditions
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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
Euphytica
Abstract
In contrast to conventional inbreeding
that takes up to seven generations to develop inbred
lines, the doubled haploid (DH) technology allows
production of inbred lines in two generations. The
objectives of the present study were to: (a) evaluate
testcross performance of 45 doubled haploid lines
under drought stress and non-stress conditions
(b) estimate heritabilities for grain yield and other
traits and (c) to assess the genetic distance and
relationship among the DH lines using 163,080 SNPs
generated using genotyping-by-sequencing (GBS).
The 45 hybrid and five checks were evaluated using
a 10 9 5 alpha lattice in six drought stress and nine
well-watered environments in Kenya, Uganda, and
Tanzania. Differences in trait means between the
drought stress and well-watered conditions were
significant for all measured traits except for anthesis
date. Genetic variances for grain yield, grain moisture,
plant height and ear height were high under
well-watered environments while genetic variance
for anthesis date, root lodging and stalk lodging were
high under drought stress environments. Combined
analyses across drought stress and well-watered
environments showed that ten top hybrids produced
1.6–2.2 t/ha grain yield under well-watered condition
and 1–1.4 t/ha under drought stress condition higher
than the mean of the commercial checks. Genetic
distance between pairwise comparisons of the 38 of
the 45 DH lines ranged from 0.07 to 0.48, and the
overall average distance was 0.36. Both cluster and
principal coordinate analysis using the genetic distance
matrix calculated from 163,080 SNPs showed
two major groups and the patterns of group was in
agreement with their pedigree. Thirteen (13) of the
best hybrids are currently in National Performance
Trials testing, an important step towards commercialization
in Kenya, Tanzania and Uganda.
Description
Keywords
Doubled haploid, Genetic distance, Drought stress, Maize
Citation
Beyene, Y., Mugo, S., Semagn, K., Asea, G., Trevisan, W., Tarekegne, A., ... & Chavangi, A. (2013). Genetic distance among doubled haploid maize lines and their testcross performance under drought stress and non-stress conditions. Euphytica, 192(3), 379-392. DOI 10.1007/s10681-013-0867-5