Aluminium tolerance in wheat: correlating hydroponic evaluations with field and soil performances*

Abstract

The objective of this study was to correlate root length of wheat (Triticum aestivum L.) genotypes grown in Al‐containing, acidic hydroponic solutions, with root weights from acid‐soil experiments and field scores from Brazilian acid‐field trials. A total of 43 wheat genotypes, primarily from Brazil, were evaluated by growing seedlings for 4 days in hydroponic solutions containing 0.0–4.0 mg/l Al. The root growth rate of all the genotypes was reduced with the addition of Al to the solution and the Al‐sensitive and Al‐tolerant wheat genotypes were clearly identified. Genotypes with intermediate Al‐tolerance levels showed variable root lengths in response to Al stress. Correlations between root length or a root tolerance index (RTI) in the Al solutions versus acid‐soil experiments and acid‐field trials were highly significant (r = 0.71–0.85, P < 0.01). The most significant correlation was observed among seedlings grown in 1 mg/1 Al. This study presents evidence that this short duration and simple screening technique provides a highly significant correlation with previous acid‐soil Al‐tolerance evaluations. Furthermore, the data obtained suggest that hydroponic screening of wheat seedlings for Al tolerance may be used in breeding programmes or in screening germplasm collections.