Effect of location on dwarf French bean (Phaseolus vulgaris L.) seed production and seedling vigour

This study examined if dwarf French bean (Phaseolus vulgaris L.) grown at northern latitudes develop seeds with superior yielding potential compared with plants grown at more southern latitudes. Two lines (BND3085 and BND3106) were grown at four sites across latitudes ranging from 52 degrees N to 3 degrees S. BND3085 and BND3106 seeds from Saskatoon grown plants (52 degrees N) had the least damaged seed coats but the highest degree of electrolyte leakage from the seed and the lowest maximum germination rates. The Saskatoon (BND3085 and BND3106) and Nunhem (BND3106) seed lots had the lowest maximum germination rates when germinated at 28 degrees C, 12 degrees C, or when exposed to saline (100 mM NaCl) conditions. Saskatoon BND3085 seed produced plants with the lowest aboveground vegetative and total seed dry matter as well as the lowest pod number per plant. In contrast, plants grown from Saskatoon BND3106 seed produced 1.5-fold more total pods, 1.3-fold more total pods and 1.4-fold higher seed dry matter per plant as compared to plants grown from the Nunhem (51 degrees N) or Arusha seed sources. This resulted in a 2.4-4.5% higher harvest index. These results suggest cultivar-specific dwarf French bean seed propagation at more northern sites may increase the productivity of the resulting crop.