Abstract: To clarify the reasons for differences in phosphorus(P) absorption and utilization in wheat with different P efficiency.Useing the platform National Long-term Monitoring Station for Chao Soil Fertility,to study the P-efficient cultivar Xuke 168 and the P-inefficient cultivar Lankao 198 differences in the root biomass, root morphology, root activity and P transport capacity under two P levels (P0 and P1 represent low P and normal P treatments,respectively).The results showed that the root dry quality, root length, root surface area, root volume generally showed that Xuke 168 was greater than Lankao 198 in the same treatment.Under P0 treatment, the root average diameter of Xuke 168 was smaller than that of Lankao 198. Except for the overwintering stage, the root average diameter of Xuke 168 was higher than that of Lankao 198 under P1 treatment. In the same treatment, the root activity of Xuke 168 was higher than that of Lankao 198.At booting stage, the root activity difference between the two cultivars was the biggest.Xuke 168 was 1.36 times that of Lankao 198 under P0 treatment, and 1.34 times that of Lankao 198 under P1 treatment. Under the same treatment, grain yield, pre-anthesis phosphorus transport and the contribution rate of post-anthesis phosphorus uptake to grain phosphorus of Xuke 168 was significantly higher than that of Lankao 198, and the contribution rate of pre-anthesis phosphorus transport to grain phosphorus of Xuke 168 was lower than that of Lankao 198. Compared with P1, the root dry quality, root length, root surface area, root volume, average root diameter, grain yield, root activity, plant P accumulation, pre-flower P transport, P uptake after anthesis and the contribution rate of post-anthesis P uptake to grain P decreased, while root-shoot ratio and the contribution of pre-anthesis P uptake to grain P increased.The P-efficient cultivar Xuke 168 has high root vitality, root biomass and developed root system,which is the basis for the absorption of P. P-inefficient cultivar Lankao 198 lacks P absorption due to its small root biomass in the early growth period, smaller root caps in the late growth period, and weak root activity, resulting in P-inefficient. In summary, higher P transport capacity, grain distribution capacity and reasonable root-shoot ratio promote the utilization of P by crops, which are important factors for crop P efficiency.

Key words: Wheat, Root morphology, Root activity, Root biomass, P efficiency, P transfer, Yield

CLC Number: 

• S143.2