| Abstract: | Common bean (Phaseolus vulgaris L.) is grown over a wide rangeof environments, including sites with low or high soil temperaturesat sowing time. To describe the temperature responseof seedgermination, 20 bean genotypes were evaluated using a rolledpaper towel system with 11 constant temperatures ranging from12 to 34 °C. Germination response was characterized by fittingcumulative counts using a maximum-likelihood analysis. Rateof germination increased from abase temperature (Tb) typicallynear 8 °C to an optimal development temperature (To) of29 to 34 °C. Tb did not differ among common bean genotypes.Mesoamerican germplasm showed slightlyhigher To than Andeangermplasm, but there was large variation in To within each ofthe two gene pools. The single accession of tepary bean (P.acutifolius) evaluated appeared to be the mosttolerant to highgermination temperatures. Key words: Common bean, seed germination rate, temperature |
