Hydroponic performance of selected gamma ray generated bean mutants in varying concentration levels of phosphorus

Abstract

Beans are a cheap source of protein for human consumption and can be a source of income. Among abiotic factors, phosphorus (P) is an important element affecting bean productivity. The objectives of this study were (i) to hydroponically evaluate gamma ray generated bean mutants with adaptive flexibility at different concentrations of P and (ii) evaluate the effectiveness of using shoot length as an indirect selection criterion for screening genotypic variability in the response to P. The experiment was set up as 5 × 13 factorial completely randomized design (CRD) replicated 3 times, with 5 doses of P, thus, 0 mg/l, 2.35 mg/l, 4.65 mg/l, 6.97 mg/L and 9.30 mg/L in nutrient medium and thirteen genotypes (G). Genotype SK 46-17-1 was identified as a better performer across P concentration. Further exploration of G x P interaction main effects revealed that genotype SK 46-17-1 performed better than the parent in all doses of P concentration except in a medium with 9.30 mg/l. Overall, the results showed that applying a concentration of 9.30 mg/L P impedes seedling productivity. Furthermore, the phenotypic variation explained (PVE) for the association between root and shoot length was found to be 19.4%. This implies that shoot length can only be used as a supplement to root length in evaluating for genotypic efficiency at utilizing P in the hydroponic medium.

Keywords:

• Phaseolus vulgaris
• Phosphorus
• root length
• hydroponic

Acknowledgement

The authors are thankful for the availability of mutant-derived lines for this research developed through funding from International Atomic Energy Agency (IAEA). Special thanks to Dr. Kalaluka Munyinda for spearheading the development of these mutants. Furthermore, thanks to Mr. Sydney Mpimpa and Mr. Alex Bwalya for their assistance in the Lab work.

Disclosure statement

No potential conflict of interest was reported by the authors.