Effect of phosphorus stress on the pigment and morphology of different maize genotypes

Four maize genotypes were selected to investigate the pigment and morphology of maize genotypes under low and high P dosage. The results show that the ratios of chlorophyll to carotenoid, purpurin and red pigment for four maize genotypes decrease under low P dose. Those of “7922” and “Ye107” are 0.4 ~ 0.8 times those under high P dose, with much higher decrease than in “178” and “*082”. PAL activity and total flavonoid content increase under low P dose. Those in “7922” and “Ye107” under low P dose are 1.5 ~ 2.0 times of those under high P dose, with much higher variation than in “178” and “*082”. Differences in leaf width and leaf fresh weight in “7922” and “Ye107” are significant between low and high P doses. The same is case for leaf chief venation diameter and leaf number in “Ye107”. Leaf width, leaf chief venation diameter, leaf number and leaf fresh weight is decreased under low P dose. A significant difference is observed in leaf pigments and maize leaf shape among the different genotypes. This implies that “7922”and “Ye107” are somehow sensitive to low P stress, while “178” and “*082” are tolerant to low P stress.