000			03545nam a22004937a 4500
001			G80354
003			MX-TxCIM
005			20240919021105.0
008			121211s ||||f| 0 p|p||0|| |
020			_a970-648-120-6
040			_aMX-TxCIM
072		0	_aE16
072		0	_aH20
082	0	4	_a338.16 _bFRI
100	1		_91818 _aMenkir, A.
110	0		_aCentro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) Kenya
111	2		_a7. Proceedings of the Eastern and Southern Africa Regional Maize Conference _cNairobi (Kenya) _d5-11 Feb 2002
245	0	0	_aRecent advances in breeding maize for resistance to Striga hermonthica (Del.) benth
260			_aNairobi (Kenya) _bKARI|CIMMYT : _c2002
300			_ap. 151-155
340			_aPrinted
520			_aStriga represents the largest biological threat to cereal production in sub-Saharan Africa. Breeding for resistance to Striga has been the focal point of IITA to reduce the impact of this parasite on maize production. The early breeding work at IITA focused on search for tolerance to Striga. IITA has made a significant shift in emphasis towards selection of resistant maize genotypes that support a reduced number of Striga plants since the early 1990s. Population improvement and the inbred-hybrid method have been used to increase the levels of resistance to Striga. An experiment was conducted to evaluate progress from five cycles of recurrent selection in a late-maturing composite, TZL COMP.1-W, at two locations for two years. Selection reduced Striga damage symptoms by 3% per cycle and number of emerged Striga plants by 10% per cycle. At the same time, grain yield in this population increased by 16% per cycle under Striga infestation and by 2% per cycle under non-infested conditions. Furthermore, several open pollinated varieties of different maturity with good levels of resistance to Striga were derived from diverse populations. The inbred-hybrid approach has also been effective in identifying inbred lines with high levels of resistance to Striga from diverse sources of germplasm. Some of these lines were evaluated in hybrid combinations at two locations with and without Striga infestation. Most of the hybrids involving these inbred lines supported fewer Striga plants and produced higher yields under infestation with Striga than a commercial hybrid. The best hybrids were also more productive than a standard Striga resistant hybrid check with much fewer emerged Striga plants. These hybrids sustained little or no yield loss under infestation with S. hermonthica. In contrast to tolerance, the selection and use of such resistant open-pollinated varieties and hybrids can reduce reproduction of seed of the parasite thereby depleting the soil innoculum in areas where the parasite is endemic.
546			_aEnglish
591			_a0410|AGRIS 0401|AL-Maize Program
593			_aJuan Carlos Mendieta
595			_aCPC
650	1	7	_aCropping systems _gAGROVOC _2 _91068
650	1	7	_aDisease resistance _gAGROVOC _2 _91077
650	1	7	_aGermplasm _gAGROVOC _2 _91136
650	1	7	_aMaize _gAGROVOC _2 _91173
650	1	0	_aSeed production _91253
650	1	0	_aStriga hermonthica
653	0		_aCIMMYT
653	0		_aKARI
650	1	0	_91134 _aGenotypes _gAGROVOC
650	1	0	_91151 _aHybrids _gAGROVOC
650	1	7	_aPlant breeding _gAGROVOC _2 _91203
700	1		_9422 _aBadu-Apraku, B.
700	1		_aFriesen, D.K.|Palmer, A.F.E. _eeds.
700	1		_aIbikunle, O., _ecoaut.
700	1		_aKling, J.G., _ecoaut.
700	1		_aThé, C., _ecoaut.
942			_cBK
999			_c7365 _d7365