Effect from horizontally dividing the root system of wheat plants having different phosphorus efficiencies

The mechanisms of phosphate (P) mobilized by wheat were studied with the typically efficient or inefficient genotypes grown in a split-pot experiment. The split-pot was composed of two parts, the lower part was a 2-L plastic pot containing two liters of nutrient solution and the upper part was a PCV tube six cm in diameter by eight cm high and with a nylon net bottom. The tube which was fixed on the pot lid held 250 g quartz sand. In the lid was drilled a small hole in order to add culture solution and 3% hydrogen perioxide (H2O2) instead of aerating. Two seedlings were planted in the quartz sand of each of the tubes. Ponnamperuma's recipe was used for preparing the culture solution. For each of the three genotypes tested, four P treatments were: (i) with 0.5 g TCP as the only P source added to the solution, (ii) with 0.5 g TCP as the only 1 Corresponding author (fax#: +86-10-6217-4142; e-mail address: [email protected]).