Incorporation of phosphorus efficiency from exotic germplasm into agriculturally adapted germplasm of common bean (Phaseolus vulgaris L.)

Summary The growth of inbred backcross (IB) lines derived from the cross of the phosphorus (P)-efficient donor parent (PI 206002) and the recurrent parent (cultivar Sanilac) was measured in low-P nutrient solution culture and in a field nursery on a soil moderately deficient in P. Several IB lines that resembled ‘Sanilac’ in general morphology were identified as P-efficient in the nutrient solution culture (10 to 25% more shoot dry weight accumulation than ‘Sanilac’). In general, these lines accumulated 30 to 50% more shoot dry weight and more P in the shoot tissue at first flower than ‘Sanilac’ in the low-P field plot but did not differ from ‘Sanilac’ in a field plot amended with P fertilizer. Some IB lines with seed yields higher than ‘Sanilac’ may have both the vegetative P efficiency of PI 206002 and the ability to convert this growth into seed production. Transfer of a quantitative trait such as P efficiency using the inbred backcross breeding method and preliminary evaluation of the IB lines in nutrient solution culture before field testing were shown to be useful techniques for developing common bean germplasm tolerant to soils low in available P. These genetically related lines should also be useful for physiological studies of P nutrition in common bean.