Response of P accumulation in wheat and maize seedlings to different substrate P levels

Wheat (Triticum aestivum L.) and maize (Zea mays L.) are very sensitive to phosphorus at seedling stage. Two varieties of wheat (“Xiaoyan 22” and “Lankao 4”) and maize (“Tunyu 65” and “Hudan 4”) were grown in Hoagland solution under different phosphate concentrations 0, 0.05 mmol (P₂O_{5)·L^-1, 0.3 mmol (P2O5)·L^-1, 0.5 mmol (P2O5)·L^-1 to investigate the response of P accumulation in wheat and maize at seedling stage to P levels in substrate. The results show a significantly difference in P accumulation in two corps under different substrate P levels. Variation in P accumulation is dependent on crop genotype, organ and the measurement time. The optimal level of P in wheat substrate is higher than that in maize during early seedling stage (25 days after seed emergence). There is, however, no observable difference between the two crops during later seedling stage (40 ~ 50 days after seed emergence). When 0.05 mmol·L^-1 treatment is used as the control, P accumulation in the entire plant of maize becomes more sensitive to substrate P level than in wheat. “Lankao 4” is more sensitive than “Xiaoyan 22” and there exists no observable difference between “Tunyu 65” and “Hudan 4”. P efficiency in wheat is higher than in maize under zero phosphate treatment, while the reverse is the case under phosphate treatment. There is no consistent relationship between different genotypes.}