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001			G80726
003			MX-TxCIM
005			20211006084755.0
008			121211s ||||f| 0 p|p||0|| |
020			_a970-648-120-6
040			_aMX-TxCIM
072		0	_aF01
072		0	_aP35
082	0	4	_a338.16 _bFRI
100	1		_aGudu, S. _uIntegrated Approaches to Higher Maize Productivity in the New Millennium
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	_aScreening of kenyan maize germplasm for tolerance to low pH and aluminium for use in acid soils of Kenya
260			_aNairobi (Kenya) _bKARI|CIMMYT : _c2002
300			_ap. 216-221
340			_aPrinted
520			_aLow soil pH is a major constraint to maize (Zea mays L.) production on tropical soils due to toxic levels of aluminium (Al) and the concomitant phosphorus (P) deficiency that hinders plant root growth. A preliminary laboratory screening was conducted to test 75 Kenyan landrace maize accessions and J 2 commercial varieties for response to low soil pH and Al toxicity in solution culture. The landrace maize accessions were screened under different levels of Al concentration (0, 100, 200, and 300 mM) at pH 4.0. A standard acid-tolerant variety (CIMCALI 97 Balopia SA4 subsequently referred to as 97BASA4) and an Al-sensitive variety (CIMCALI 97BSA3-1) from CIMMYT were included as controls. Preliminary classification of the 75 randomly chosen landrace accessions into tolerant/sensitive phenotypic classes was based on the FRL, Rti and haematoxylin staining of seedling grown in a solution culture containing 200 mM Al at pH 4.0, but the final screening of commercial hybrids/synthetics/composites was done in similar medium at 220 mM Al. The most consistently tolerant accessions based on FRL and Rti were, 1X1 , 5A, 203B, and 4D, and the most consistently sensitve accessions were 306A, 306B and 7B2, while the rest of landrace accessions had intermediate tolerance or sensitivity when compared with 97BASA4 and 97BSA3-1. Interesting observations were made when four selected tolerant landrace accessions (203B, SA, 4D and 1X1) and two susceptible accessions (306A and 306B) were tested against 13 commercial hybrids, synthetics and composites at 220 mM Al. The most tolerant commercial varieties were DH02 and HS13 while the most sensitive were H623 and H62S and the rest were of intermediate tolerance or sensitivity. It is interesting to note that some of tl1e commercial varieties and landrace accessions were sensitive to Al concentrations as low as 140 mM typically found in some high potential maize producing areas of Kenya indicating that Al toxicity could be one of the major causes for the low maize yields in acid soils of Kenya. Secondly, there is high variability in tolerance to Al toxicity among Kenyan commercial varieties and landrace maize populations that may be useful in selection for A1-tolerant materials for use in acid soils in Kenya..
546			_aEnglish
591			_a0410|AGRIS 0401|AL-Maize Program
593			_aJuan Carlos Mendieta
595			_aCPC
650	1	0	_aAcid soils
650	1	0	_aCrop husbandry _91058
650	1	7	_aGermplasm _gAGROVOC _2 _91136
650	1	0	_aKenya _91167
650	1	7	_aMaize _gAGROVOC _2 _91173
650	1	0	_aSeed production _91253
650	1	0	_aTropical soils
653	0		_aCIMMYT
653	0		_aKARI
650	1	0	_91314 _aZea mays _gAGROVOC
650	1	0	_91151 _aHybrids _gAGROVOC
700	1		_aFriesen, D.K.|Palmer, A.F.E. _eeds.
700	1		_aLigeyo, D.O., _ecoaut.
700	1		_aMaina, S.M., _ecoaut.
700	1		_aOmbakho, G., _ecoaut.
700	1		_aOnkware, A.O., _ecoaut.
942			_cBK
999			_c7374 _d7374