Maternal doubled haploid production in interploidy hybridization between Brassica napus and Brassica allooctaploids

The doubled haploid breeding method and greenhouse screening using cotyledon bio-assay were successfully applied to transfer blackleg resistance from the Australian cultivar Maluka (Brassicas napus), into susceptible advanced B. napus lines from the University of Alberta. This approach for blackleg resistance breeding was effective and efficient as several superior blackleg resistant breeding lines were identified within 4 yr from the initial cross. One of these lines (91–21864NA) was entered in the 1993 trials of the Western Canada Canola/Rapeseed Recommending Committee. Key words: Blackleg resistance, Leptosphaeria maculans, doubled haploid, Brassica napus

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Detection and Effects of a Homeologous Reciprocal Transposition in Brassica napus

Genetics ◽

10.1093/genetics/165.3.1569 ◽

2003 ◽

Vol 165 (3) ◽

pp. 1569-1577

Author(s):

Thomas C Osborn ◽

David V Butrulle ◽

Andrew G Sharpe ◽

Kathryn J Pickering ◽

Isobel A P Parkin ◽

...

Keyword(s):

Brassica Napus ◽

Genetic Mapping ◽

Doubled Haploid ◽

Selective Advantage ◽

F1 Hybrids ◽

Rflp Markers ◽

Cytological Analysis ◽

Linkage Groups ◽

Homeologous Chromosomes ◽

Seed Yields

Abstract A reciprocal chromosomal transposition was identified in several annual oilseed Brassica napus genotypes used as parents in crosses to biennial genotypes for genetic mapping studies. The transposition involved an exchange of interstitial homeologous regions on linkage groups N7 and N16, and its detection was made possible by the use of segregating populations of doubled haploid lines and codominant RFLP markers. RFLP probes detected pairs of homeologous loci on N7 and N16 for which the annual and biennial parents had identical alleles in regions expected to be homeologous. The existence of an interstitial reciprocal transposition was confirmed by cytological analysis of synaptonemal complexes of annual × biennial F1 hybrids. Although it included approximately one-third of the physical length of the N7 and N16 chromosomes, few recombination events within the region were recovered in the progenies of the hybrids. Significantly higher seed yields were associated with the parental configurations of the rearrangement in segregating progenies. These progenies contained complete complements of homeologous chromosomes from the diploid progenitors of B. napus, and thus their higher seed yields provide evidence for the selective advantage of allopolyploidy through the fixation of intergenomic heterozygosity.

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Optimization of chromosome doubling treatment for efficient in vivo doubled haploid production in maize

Israel Journal of Plant Sciences ◽

10.1163/22238980-bja10020 ◽

2021 ◽

pp. 1-10

Author(s):

Sourbh Kumar ◽

Uttam Chandel ◽

Satish Kumar Guleria

Keyword(s):

Doubled Haploid ◽

Seed Set ◽

Chromosome Doubling ◽

Pollen Viability ◽

Haploid Inducer ◽

Haploid Production ◽

Maize Genotypes ◽

Different Doses

Abstract An investigation to optimize the protocol for application of colchicine for enhancing the doubled haploid production in maize was done. 106 maize genotypes were used as maternal parents, whereas, pollen source involved tropically adopted haploid inducer (TAIL P1 and TAIL hybrid). After the elimination of chromosomes of inducer lines, haploid seeds were obtained from the crosses. Haploid seedlings were treated with three different doses, such as 0.04, 0.06 and 0.08 per cent of colchicines for different durations (8, 12 and 15 hours). The response of various colchicine concentrations applied for different time durations revealed significant differences at P ≤ 0.05 for various parameters viz., per cent plants survivability, stalk colour, the fertility of tassel, silk present/absent, pollen viability, seed set and per cent doubled haploid formation. In maize, colchicine doses of 0.04 per cent for 12 hours and 0.06 per cent for 8 hours, respectively were established as optimum for enhanced doubled haploid production. But among these two, 0.04 per cent for 12 hours was observed to be best dose for doubled haploid production in maize.

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