TAGGING OF THE SPECIFIC GENOME AND CHROMOSOME(S) OF HEXAPLOID WHEAT TRIGGERING CHROMOSOME ELIMINATION IN WHEAT x IMPERATA CYLINDRICA SYSTEM OF DOUBLED HAPLOIDY BREEDING
KrishiKosh
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Title |
TAGGING OF THE SPECIFIC GENOME AND CHROMOSOME(S) OF HEXAPLOID WHEAT TRIGGERING CHROMOSOME ELIMINATION IN WHEAT x IMPERATA CYLINDRICA SYSTEM OF DOUBLED HAPLOIDY BREEDING
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Creator |
KAILA, VINEETA
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Contributor |
Chaudhary, H. K.
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Subject |
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Plant Breeding ##Unable to generate tags ijcmiid_vol.8(3)_1987.pdf Wheat |
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Description |
Doctoral Dissertation
The present research endeavour entitled as “tagging of the specific genome and chromosome(s) of hexaploid wheat triggering chromosome elimination in wheat x Imperata cylindrica system of doubled haploidy breeding” was undertaken at Molecular Cytogenetics & Tissue Culture Lab and Experimental Farm of the Department of Crop Improvement, CSK HP Agricultural University, Palampur, Himachal Pradesh, India during 2010- 11 and 2011- 12 with the objective of identifying the wheat genomes and chromosomes responsible for elimination of whole I. cylindrica chromosome complement in wheat x I. cylindrica hybrids during early embryogenesis. Upon hybridization of different species of wheat viz., Triticum monococcum, T. tauschii and T. durum with I. cylindrica, haploid embryos were recovered in T. tauschii and T. durum only which revealed that the D and B genomes of hexaploid wheat are triggering the paternal chromosome elimination process. The possibility of enhancing the efficiency of embryo formation via increasing the exogenous supply of 2,4-D was also exploited and 0.03 % and 0.04 % of 2,4-D concentration were found optimum for haploid induction in T. durum and T. tauschii, respectively. The induction of haploid embryos in these species was also confirmed by cross-sectional studies of fertilized ovules derived after their hybridization with I. cylindrica. For further resolution of the genetic control of paternal chromosome elimination in wheat x I. cylindrica crosses, cytogenetic stocks viz., complete set of monosomic and nullisomic lines derived from ‘Chinese Spring’ cultivar of hexaploid wheat and D genome substitution lines of tetraploid wheat cultivar ‘Langdon’ were crossed with I. cylindrica. Statistical analysis of embryo formation frequency in monosomics revealed the role of 4D, 1D, 6B and 6D chromosomes as the absence of these chromosomes resulted in reduction of haploid embryo formation frequency from control as well as mean. These results were also supported by data obtained from nullisomics and substitution lines. Morphological characterization of monosomic series was carried out on the basis of 24 traits to identify visual markers for differentiation of aneuploids from disomic plants. Eight morphological descriptors were identified for differentiation of nullisomics, that is, seed size, plant height, spike length, number of tillers, florets per spike, seeds per spike, days to flowering and 100 seed weight. Whereas, two descriptors were identified in case of monosomics viz., spike shape for 5A and days to flowering for 2B monosomic. |
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Date |
2016-08-05T12:27:30Z
2016-08-05T12:27:30Z 2013 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/71028
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Language |
en
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Format |
application/pdf
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Publisher |
CSK Himachal Pradesh Krishi Vishavavidyalaya, Palampur
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