Growth and carbon partitioning of two genotypes of bean (Phaseolus vulgaris) grown with low phosphorus availability

Production of the common bean (Phaseolus vulgaris) is often limited by the low availability of soil phosphorus (P). Bean genotypes differ in their P efficiency, dry matter production and partitioning under low P availability. Two genotypes of bean were used in this study cv. Carioca (CNF 0554) with indeterminate growth habit (GH) and small seeds and cv. Prince (commercially available) with a determinate GH and large seeds. Plants were grown in a solution culture with either a non-limiting or low P supply and harvested at two occasions to measure dry matter production (DM), DM partitioning, and growth parameters. The determinate genotype produced a higher DM than the indeterminate genotype, due to the larger seeds. At low P supply increased the root dry weight and decreased the leaf and stem dry weight. No effect was detected on the total DM. The DM partitioning follows the same pattern as DM production. Carioca invests less dry matter in the stem, and more dry matter in the root. Low P availability also reduced the leaf area (LA), leaf area ratio (LAR) and specific leaf area (SLA). Growth was affected differently between the genotypes by low P. There was a reduction in relative growth rates (RGR) and net assimilation rates (NAR) for Carioca, but no effect was found in Prince. A genetic variation for P response exists in bean genotypes with different growth habits.