000			03996nab a22004337a 4500
001			G93497
003			MX-TxCIM
005			20240919021148.0
008			211001s2009 xxk|||p|op||| 00| 0 eng d
022			_a1744-7348 (Online)
022			_a0003-4746
024	8		_ahttps://doi.org/10.1111/j.1744-7348.2009.00351.x
040			_aMX-TxCIM
041			_aeng
090			_aCIS-5660
100	1		_aReynolds, M.P. _gGlobal Wheat Program _8INT1511 _9831
245	1	0	_aPhenotyping approaches for physiological breeding and gene discovery in wheat
260			_aUnited Kingdom : _bWiley, _c2009.
500			_aPeer review
500			_aPeer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0003-4746
520			_aConceptual models of drought-adaptive traits have been used in breeding to accumulate complementary physiological traits (PT) in selected progeny, resulting in distribution of advanced lines to rain-fed environments worldwide by the International Maize and Wheat Improvement Center (CIMMYT). Key steps in PT breeding at CIMMYT include characterisation of crossing block lines for stress adaptive mechanisms, strategic crossing among parents that encompass as many target traits as possible and early generation selection (EGS) of bulks for canopy temperature (CT). The approach has been successful using both elite × elite crosses as well as three way crosses involving stress adapted landraces. Other EGS techniques that are amenable to high throughput include measurement of spectral reflectance indices and stomatal aperture-related traits. Their genetic- and cost-effectiveness are supported by realisation of genetic yield gains in response to trait selection, and by economic analysis, respectively. Continual reselection within restricted gene pools is likely to lead to diminishing returns, however, exotic parents can be used to introduce new allelic diversity. Examples include landraces from the primary gene pool, and products of inter-specific hybridisation with the secondary gene pool consisting of closely related wheat genomes. Both approaches have been successful in introducing stress-adaptive traits. The main problem with knowing which genetic resource to use in wide-crossing is the uncertainty with which phenotypic expression can be extrapolated from one genome/genepool to another because of their unimproved or undomesticated genetic backgrounds. Nonetheless, their PT expression can be measured and used as a basis for investing in crossing or wide crossing. Discovering the genetic basis of PT is highly complex because putative QTLs may interact with environment and genetic background, including genes of major effect. Detection of QTLs was improved in mapping populations where flowering time was controlled, while new mapping populations have been designed by screening potential parents that do not contrast in the Rht, Ppd and Vrn alleles. Association genetics mapping is another approach that can be employed for gene discovery using exclusively agronomically improved material, thereby minimising the probability of identifying yield QTLs whose alleles have been already improved by conventional breeding.
536			_aGlobal Wheat Program
546			_aText in English
594			_aINT1511
650		7	_2AGROVOC _91310 _aWheat
650		7	_2AGROVOC _91080 _aDrought
650		7	_2AGROVOC _91831 _aPhysiology
650		7	_aPlant breeding _gAGROVOC _2 _91203
650		7	_2AGROVOC _96305 _aLandraces
650		7	_2AGROVOC _93155 _aResistance varieties
650		7	_2AGROVOC _95934 _aGene pools
650		7	_2AGROVOC _91853 _aQuantitative Trait Loci
700	0		_aYann Manes _95665
700	1		_aIzanloo, A. _923536
700	1		_aLangridge, P. _98803
773	0		_tAnnals of Applied Biology _gv. 155, no. 3, p. 309-320 _dUnited Kingdom : Wiley, 2009. _wG444142 _x1744-7348
856	4		_yAccess only for CIMMYT Staff _uhttps://hdl.handle.net/20.500.12665/1565
942			_cJA _2ddc _n0
999			_c27883 _d27883