Studies of phosphorus uptake and accumulation of cold type wheat

Previous studies indicated that the canopy temperature was different among different wheat genotypes after anthesis.There were many reports about the physiological,anatomic and ecological characteristics of different wheat genotypes with lower and higher canopy temperature,but little about their nutritional traits.The objective of this study was to probe the P uptake and accumulation characteristics of genotypes with lower canopy temperature.Field experiments were conducted from 2002 to 2004 at the Agricultural Experimental Station of Northwest A F University,Yangling,Shaanxi Province,China.It is a sub-humid area susceptible to drought.The genotypes(Xiaoyan 6 and Shaan 229) have lower canopy temperature and were named cold type wheat(CTW).NR9405 and 9430 have higher canopy temperature,so they belong to warm type wheat(WTW).Each genotype received four fertilizer treatments: CK(no fertilizer),P fertilization(P2O5 176.2 kg/ha),N fertilization(N 237.0 kg/ha),and NP fertilization(P2O5 176.2 kg/ha plus N 237.0 kg/ha).The treatments(variety fertilizer) used a factorial arrangement in a 44 randomized complete block design.Each treatment was replicated three times.The area of each plot was 2.1 m2.The soil was classified as Eum-Orthic Anthrosol,equivalent to an Udic Haplustalf in the USDA system.The soil had the following characteristics: OM,9.6 g/kg;total N,1.1 g/kg;available N(NO3-+NH4+),17.5 mg/kg;available P,12.3 mg/kg and available K2O,141.2 mg/kg.The results showed that there was no difference in P accumulation capability before anthesis of CTW and WTW,but the P accumulation in flag leaves and ears etc of CTW was higher than that of WTW.P uptake rate of CTW was 24.4% higher than that of WTW during filling stage.P accumulate rate in grain of CTW was 6.3%、11.1%、18.5% and 50.6% higher than those of WTW in the CK,P,N and NP treatments,respectively,at maturity stage.It is concluded that the CTW genotypes have higher P uptake capacity than WTW and are more responsive to N and P fertilizers.