Phosphorus Stress Induced Variations in Growth Behavior and P Efficiency amongBrassicaCultivars Grown with Sparingly Soluble P Sources

Abstract

To evaluate phosphorus (P)-stress-induced relative growth responses, P-efficiency characteristics, P remobilization, and redesign in root architectural systems, Brassica cultivars were grown with sparingly soluble rock phosphate and calcium phosphate [Ca 3 (PO 4 ) 2 ] or with low/high P supply in solution and sand culture experiments. Tested cultivars showed considerable genetic diversity in biomass accumulation, concentration and contents of P, P-stress factor (PSF), and P-efficiency characteristics [P-utilization efficiency (PUE), P efficiency (PE), and P-efficiency ratio (PER)]. Statistically significant correlations were observed between P efficiency and growth parameters. Elongation rates of primary roots decreased but the length of lateral roots and branched zone elongation rates increased under P starvation. Cultivars remobilized P from metabolically inactive to active sites in P-stressed plants that may have helped low-P-tolerant cultivars to establish a better rooting system, which provided basis for enhanced P-use efficiency and tolerance against P stress. Cultivars depicting high P efficiency and low PSF values were more tolerant and are a better choice to grow under P-stress environments.

Genotypic Variations in Growth Response and P-acquisition Efficiency by Spring Wheat Cultivars Exposed to Sparingly Soluble P-sources

“…2a-b). In the present study, cultivars grown with stress/low levels of P produced less DM than those grown with adequate P (control treatment), which was in agreement with earlier studies in wheat [16]- [18] and in Brassica [19] crop cultivars. The class-II cultivars (Fareed-06 and Lasani-08) exhibited more reduction in biomass in comparison with the class-I cultivars (Mairaj-08 and BWP-97), and this decline in biomass of the plants highlights more sensitivity of the class-II cultivars exposed to P-stress deficiency environment.…”

Phosphorus Uptake and Growth of Wild-Type Barley and Its Root-Hairless Mutant Cultured in Buffered-and Non-Buffered-P Solutions

“…At harvest, shoots cut from roots of the left and right root halves (in the split-root system) were carefully separated for measuring the dry weight (biomass), and the P concentration in the plant tissue. Harvested shoot and root tissues were thoroughly rinsed with distilled water to wash TCP particles and other nutrients off, and dried in an oven at 75 • C for 72 h. Shoot and root dry weights were measured and the root to shoot ratio were calculated [21].…”