Temperature and pH of the nutrient solution on wheat primary root growth

Primary root growth is very important for wheat (Triticum aestivutn L.) crop in upland conditions in the State of Sao Paulo. Fourteen wheat genotypes (mutant lines and cultivars) were evaluated for primary root growth during 7 and 15 days of development in complete and aerated nutrient solutions, in the laboratory. In the first experiment, solutions with three pH values (4.0, 5.0 and 6.0) at constant temperature (24 +/- 1degreesC), and in the second experiment, solutions with the same pH (4.0) but with three temperatures (18degreesC +/- 1degreesC, 24degreesC 1degreesC and 30degreesC 1degreesC) were used. High genetic variability was observed among the evaluated genotypes in relation to primary root growth in the first stages of development in nutrient solutions independent of pH, temperature and growth period. Genotypes 6 (BH- 1146) and 13 (IAC- 17), tolerant to Al3+ showed genetic potential for root growth in the first stages of development (7 and 15 days), regardless of nutrient solution temperature and pH. Genotypes 14 (IAC-24 M), 15 (IAC-24), 17 (MON"S" / ALD "S") x IAC-24 M-2, 18 (MON"S" / ALD "S") x IAC-24 M-3 and 24 (KAUZ"S" / IAC-24 M-3)' tolerant to AV+, showed reduced root growth under the same conditions.