Genetic variability for aluminum tolerance between and within progenies of leucaena

Abstract

In a nutrient solution containing 9 ppm Al, 18 single-plant progenies of leucaena, Leucaena leucocephala (Lam.) de Wit., from three populations considered to be tolerant to Al by means of the multivariate analysis were tested. The experiment was set up in a randomized complete block design with four replications, each plot being comprised by a different progeny; ten plants were used par plot, comprising 40 plants per progeny over the four replications. Four weeks after transplanting the germinated seeds to the nutrient solution, the following traits were evaluated: length of the aerial portion (Y₁) length of the longest root (Y₂), dry weight of the aerial portion (Y₃), dry weight of roots (Y₄) and cotyledon persistence (Y₅). Genetic variability was shown to be present among progenies and within some progenies of Ieucaena, demonstrating the possibility of improving Al tolerance in L. leucocephala by means of intrapopulational selection. Mutual agreement between the results yielded by parameters Y₁, Y₂, Y₃, Y₄ and Y₅ was less than satisfactory, underlining the difficulty in the use of a single parameter in the evaluation of Al tolerante in leucaena.