Abstract:

Three wheat (Triticum aestivum L.) cultivars with different phosphorus (P) efficiency and the hybrid F1s from the careers between three cultivars were used to compare phosphorus acquisition and utilization properties under P-deficient conditions. As compared with cultivar with low P efficiency (Nc37), cultivar with high P acquisition efficiency [81(85)] had much more secondary root number per plant, larger diameter of secondary root, higher root dry weight per cm3 soil（Fig.1）, higher TTC reductive activity in root and much more accumulation of P in plant(Fig.2, 3). Its increase of P uptake under P-deficient condition was due to the changes of root amount and the enhancement of acquisition of insoluble phosphorus from the soil. The higher APase activity in flag leaf possibly had important role to improve the utilization efficiency of P in cv. Mazhamai by promoting the metabolic circling and re-utilization of P in plants (Fig.4). The Hm (heterosis from mid-parent value) and Hh (heterosis from high-parent value) on secondary root number per plant, diameter of secondary root, root dry weight per cm3 soil, TTC reductive activities in root, total P content in plant and APase activity in flag leaves were almost all positive values(Table 1, 2). The Hm and Hh of grain yield per plant in three hybrid F1s were 31.7%–32.8% and 18.5%–29.6%, respectively（Table 1）.Making the hybrid combinations from the parents with high acquisition efficiency and variety with high utilization efficiency of P, and fully utilizing the heterosis of F1 on acquisition and utilization of P, will possibly have important roles to improve the P nutrition of wheat under P-deficient condition.

Key words: Phosphorus efficiency, Wheat (Triticum aestivum L.), Hybrid F1, P-deficient condition