Development and genetics of maize doubled haploid lines


The present study was carried out to develop doubled haploid lines using in-vivo maternal haploid induction technique.
The study was aimed at the reliability of haploid seed identification through the R1-nj visual colored marker,
identification of spontaneous doubling in tropical germplasm, optimization of colchicine percentage and seedling
cutting methods for artificial chromosome doubling and revealing the genetics of newly developed DH-lines. Two
tropical haploid inducer lines with 4-6% HIR were used as male parents and crossed with a single hybrid FH-949
as female donor parent. The R1-nj visual colored marker was used to sort haploid from diploid kernels. To check
the spontaneous chromosome doubling rate these haploid kernels were grown in the field. In the laboratory, different
colchicine percentages and seedling cutting treatments were used to double these maternal haploids. The
data for seedling survival and DHo seed formation was collected and generalized linear model GLM was used to
interpret treatment results. SAS 9.2 was used to estimate confidence intervals for the binomial proportion having
zero frequencies. Out of twenty doubled haploid lines developed, five were crossed with three OPVs in line ×
tester mating design. The data was collected and evaluated for combining ability and type of gene action for the
yield and its related traits. The R1-nj dominant anthocyanin marker was found to be 91 percent effective in identifying
maternal haploid seeds at the dormant stage. The spontaneous doubling percentage of maternal haploids
was recorded 0.8%. All the lines showed good general combining ability. The additive type of gene action was
prevailing in most of the traits studied.


Maternal haploid, spontaneous doubling, artificial chromosome doubling, combining ability, maize

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013