Seed multiplication and preliminary evaluations of Phaseolus coccineus germplasm collection at C.I.A.T. (Centro Internacional de Agricultura Tropical, Cali, Colombia)

Seed increase of the 1300 accessions from both the cultivated subspecies (coccineus and polyanthus) and the wild forms of Phaseolus coccineus is being carried out at 2 locations of Colombia. In Popayan (1700 m alt., 18 degrees Celsius mean temp., and 2000 mm annual rainfall), 12 plants of each accession are grown in mesh cages. Flowers are hand-pollinated with pollen from the same plants or plants from the same population. In total, 70 accessions can be multiplied twice a year at this location. In Rionegro (2200 m alt., 17 degrees Celsius mean temp. and 1850 mm annual rainfall), 18 plants from each accession are grown in the open field. Plant are hand-pollinated in the same way as in Popayan but paper bags are used to protect the hand-pollinated racemes from insect activities. This method allows the seed increase of 350 accessions a year. A preliminary screening of accessions of the subspecies polyanthus has also been carried out to identify sources of resistance to Ascochyta. Four of the accessions tested were particularly outstanding: G 35336 and G 35182 (from Guatemala), G 35337 (from Mexico), and G 35372 (from Colombia). (CIAT)