Abstract—To estimate genetic variability in growth characteristics and phosphorus acquisition efficiency from sparingly soluble P-sources; four genetically diverse spring wheat cultivars, categorized as ‘P-efficient and low P-tolerant (class-I), and P-inefficient and low P-sensitive (class-II) cultivars’ based on P-efficiency characteristics in a hydroponic study, were grown in a sand culture in order to evaluate their relative performance in a glass house experiment. Pre-treated, cleaned uniform sized seeds of cultivars were sown in 4-kg capacity pots containing yamazuna sand with negligible available P. P-treatments were (i) (LP)-control treatment without any applied P (ii) (AP)-NH₄H₂PO₄ @ 200 μM P kg^-1 as an adequate P-supply, (iii) (TCP)-tri-calcium phosphate (Ca₃(PO₄)₂ @ 0.5 g kg^-1, and (iv) (RP)-rock phosphate @ 0.5 g kg^-1 of sand. Tri-calcium phosphate and rock phosphate were sparingly soluble P-sources containing negligible P soluble in water. Biomass accumulation by plants, P-concentration and uptake in roots and shoots of plants, phosphorus stress factor and P-efficiency characteristics were differed in tested cultivars indicating sufficient genetic diversity in wheat cultivars. Biomass and growth parameters were significantly correlated with plant P-parameters indicating that P taken up by the plants from sparingly soluble P-sources was accumulated into the plant biomass. Class-I cultivars exhibited better performance than class-II cultivars indicating their better ability to scavenge P at all P levels.

Index Terms—Sources with sparingly soluble P, P-efficiency, P-stress factor, spring wheat cultivars.

M. Shahbaz Akhtar is with Department of Environmental Management Engineering, Graduate School of Environmental & Life Science, Okayama University, Okayama, Japan. He is also with Department of Soil & Environmental Sciences, University College of Agriculture, University of Sargodha, Sargodha, Pakistan (email: drakhtarms@gmail.com).
Yoko Oki, Yoshitaka Nakashima are with Department of Environmental Management Engineering, Graduate School of Environmental & Life Science, Okayama University, Okayama, Japan.

Cite: M. Shahbaz Akhtar, Yoko Oki, Yoshitaka Nakashima, "Genotypic Variations in Growth Response and P-acquisition Efficiency by Spring Wheat Cultivars Exposed to Sparingly Soluble P-sources," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 8, no. 3, pp. 187-194, 2018.