N Deprivation in Maize During Grain-Filling. II. Remobilization of 15N and 35S and the Relationship between N and S Accumulation1
- J. W. Friedrich and
- L. E. Schrader2
The role of N and S remobilization in ear development of maize (Zea mays L.) has not been adequately assessed. The objective of this greenhouse experiment was to determine the effect of N deprivation during grain-filling on N and S remobilization and the relationship between N and S accumulation. Maize plants were grown in nutrient solution containing 15N-nitrate and 35S-sulfate. After silking, the plants were placed in unlabelled solutions, with or without nitrate-N. The amount of labelled and unlabelled N and S in several plant fractions was determined at silking and 1, 2, 3, 5, and 7 weeks after silking. The remobilization of labelled N and S was not markedly affected by N deprivation. Unlabelled N (when supplied) and unlabelled S accumulated in all plant fractions, but did not affect the concentration of N or S in the ear. Nitrogen deprivation resulted in only a 19% decrease in ear N content. Labelled N constituted 100% of the total ear N in plants deprived of N as compared to 84% for control plants. Labelled S comprised 73% of the total ear S in N-derived plants as compared to 56% in plants supplied with N. The ratio of reduced N to reduced S (NR/SR) in the ear was lower in N-deprived plants. The NR/SR, ratio in the leaves was not affected by N deprivation, and declined during grain-filling. Apparently, the remobilization of N and S contributes more to ear development than does the absorption of N and S after silking.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .