PLANT-REGENERATION FROM CALLUS IN A RANGE OF PHASEOLUS-ACUTIFOLIUS GRAY,A. GENOTYPES

The ability of a range of Phaseolus acutifolius A. Gray genotypes to r egenerate shoots from callus was investigated. Shoots and viable plant s were obtained from green nodular callus derived from buds and pedice ls. Seven of 12 genotypes tested produced morphologically normal shoot s. Regenerants of six genotypes were established in the greenhouse. Th e regeneration response reflected the taxonomic subdivision of the spe cies in that P. acutifolius var. acutifolius was responsive whereas va r. tenuifolius was not. The 'regeneration competence' trait was presen t in both the wild and the domesticated gene pools. The possible appli cation of this trait for the genetic improvement of the related and ec onomically more important species P. vulgaris is discussed.