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008			220811s2004 at ||||| |||| 10| 0 eng d
020			_a1 920842 21 7
040			_aMX-TxCIM
041			_aeng
072		0	_aA50
072		0	_aF30
090			_aCIS-4326
100	1		_aWarburton, M.L. _94138
245	1	0	_aIdentifying the source of new variation seen in synthetic backcross derived bread wheat
260			_aGosford (Australia) : _bThe Regional Institute, _c2004.
340			_aComputer File|Printed
500			_aDraft
520			_aThe expansion of the bread wheat gene pool can be achieved via the creation of synthetic hexaploid wheats (SHWs) and the backcrossing of these synthetics to elite breeding lines. Resistance to many biotic and abiotic stresses has been incorporated into new bread wheat cultivars using synthetic donors. Sufficient microsatellite markers (SSRs) were used to create a dense coverage of all the chromosomes to assess the genetic diversity present in synthetic hexaploid wheats, their backcross derived families, and their parents (where possible). SSRs were also used to test for the selective advantage of SHWs alleles in backcross families after several generations of selection. The SHWs investigated in this study had a high gene diversity and PIC for all SSRs, but highest for D genome markers. The SHWs clustered with their durum parents, but were clearly separated from bread wheat cultivars in a dendrogram. Gene diversity of the synthetic backcross derived lines (SBLs) for the A and B genomes was higher than that of their SHW and bread wheat parents. Gene diversity partitioned within each SBL family was extremely high. Principal coordinates analysis of the SBLs and their parents showed that lines from each SBL family clustered together and closer to their bread wheat parent than their SHW parent. De novo generation of genetic variation was seen in many of the SHWs, which was stably inherited in the SBL families. Non-Mendelian inheritance of alleles favoring the SHW parent was seen in some of the markers in one or more SBL families, suggesting that these genomic regions are being actively selected for.
536			_aGlobal Wheat Program
546			_aText in English
591			_a0503|AL-Wheat Program
594			_aINT2692
650		7	_91125 _aGenetic diversity _2AGROVOC
650		7	_915354 _aBackcrossing _2AGROVOC
650		7	_92020 _aHexaploidy _2AGROVOC
700	0		_aPingzhi Zhang _95892
700	1		_9851 _aDreisigacker, S. _gGlobal Wheat Program _8INT2692
700	1		_aLage, J. _920327
700	1		_997 _aGinkel, M. Van
700	1		_9341 _aTrethowan, R.M.
711	2		_94324 _aInternational Crop Science Congress _n(4th : _dSeptember 26 – October 1, 2004 : _cBrisbane, Australia)
773	0		_dGosford (Australia) : The Regional Institute, 2004. _tNew directions for a diverse planet: Proceedings of the 4th International Crop Science Congress _wG81984 _z1 920842 20 9
942			_cBP _2ddc _n0
999			_c45723 _d45723