Indian Society of Genetics & Plant Breeding

R1-nj expression in parental inbreds as a predictor of amenability of maize hybrids to R1-nj-based doubled haploid development

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The current method of doubled haploid (DH) development
in maize involves
in vivo production of haploids using R1-
-based haploid inducer lines that upon use as male render
a small fraction of seed in the pollinated female ears haploid.
Identification of haploid seed relies on
R1-nj marker
expression in the endosperm and embryo, and the degree
of its expression determines efficiency of DH development
process. In the present study,
R1-nj expression in the
endosperm was characterized in crosses of CIMMYT’s
-based haploid inducer TAILP1 with a set comprising 18
early maturity hybrids and their 23 parental inbreds. Kernel
colour inhibition was observed only in a small proportion
of the hybrids and inbreds. Comparison of
R1-nj expression
in the hybrids and their parental inbreds revealed a distinct
pattern, which may be useful in identifying source
populations and/or determining parental constituents for
synthesizing source populations with predicted amenability
to doubled haploid development using
R1-nj-based haploid
inducers. However, deviation from the pattern was noted
in hybrids involving inbreds with higher degree of colour
inhibition, which suggests complex nature of
phenotype expression and necessitates further
investigation involving larger sets of germplasm for
dissecting the role of maternal and paternal genetic factors
in determining
R1-nj phenotype expression. The hybrids
found exhibiting complete kernel anthocyanin expression
in present study can be used directly as source populations
for DH development using
R1-nj based haploid inducers.
Besides, since the inbreds used in the study have originated
from and/or are accessible to CGIAR/NARS maize breeding
programmes, the information on their kernel anthocyanin
expression can be helpful in selection of source populations
or generating new source populations amenable for DH
development using
R1-nj based haploid inducers.  

Keywords: Maize, haploid inducer, R1-nj expression, doubled haploid, amenability


Year: 2019
Volume: 79
Issue: 4
Article DOI: 10.31742/IJGPB.79.4.5
Print ISSN: 0019-5200
Online ISSN: 0975-6906



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