Abstract:

A wheat (Triticum aestivum L.) cultivar CA9325 was cultured in quartz sand and nutrient solution with the treatments of P supplied all the time and P deficiency at flagging stage. At anthesis stage, plants were treated with removing partial spikelet and daubing NAA or not on the incision part. The results showed that at maturity, the dry weight and P content were the highest in grains and the lowest in flag leaves. In P supply treatments, dry weights of different organs were higher in CK than in those with 1/3 spikelets removal, and less than in those with 1/4 or 1/5 spikelets removal. Dry weight of roots, ratio of root to shoot, 1 000-grain weight and P content in all plants removed partial spikelets showed a compensatory increase. Grains and whole plant with 1/4 spikelets removal both had the highest dry weight and P content. This was a significantly negative correlation between P accumulation in the plant and P utilization efficiency in grains. In the removing partial spikelets treatments, dry weight and P accumulation in grains were higher in the combined treatments daubed by NAA than in those no NAA, indicating that NAA has a positive capacity to regulate and control grain construction, sink potential, assimilate and P transportation and distribution in plant and accumulation in grains.

Key words: Wheat (Triticum aestivum L.), Sink size, NAA, Assimilate, Phosphorus, Distribution