Genotypic Differences of Corn for Ion Uptake¹

Abstract

Efficiency of fertilizer uptake may be improved by selecting genotypes that absorb a greater proportion of the nutrients in the soil. The objective of this investigation was to examine genotypic differences in ion influx (uptake rate per cm of root) properties of corn (Zea mays L.) roots that may influence efficiency of fertilizer uptake. Six genotypes developed in Florida and six genotypes developed in Indiana were investigated. Each represented two single‐cross hybrids and their parents. They were grown for 15 days in nutrient solution in a controlled climate chamber and the influx parameters of K, Ca, Mg, and P were determined by measuring the depletion of these ions from solution. All hybrids exhibited heterosis in the growth of shoots and roots. Florida genotypes had finer roots than Indiana genotypes. Florida genotypes had higher average Imax (maximum influx) values for Ca and P. Parent lines of Florida hybrids had higher average Imax values for Ca and lower for K and Mg than hybrids. Indiana genotypes had higher average Km, Michaelis‐Menten, values for K uptake and lower Km values for P uptake than Florida genotypes. Florida genotypes had significantly higher average Cmin (concentration in solution where net influx is zero) values for Mg and P and lower for K than Indiana genotypes. Even though Florida and Indiana genotypes originated in different geographic regions they exhibited little difference in their average net influx rates for Ca and Mg, however, there were small but significant differences between these genotypes in average influx values for P and K. Florida inbreds with higher P influx rates tended to have hybrids with higher P influx rates. While the differences in this study were not large, investigation of a larger number of genotypes is needed to determine the possibilities of developing hybrids with roots that are more effective nutrient absorbers.

Kinetics of phosphorus uptake and root morphology of local and improved varieties of maize

“…(Table 4). Baligar & Barber (1979), in a study with several maize genotypes, observed that the genotype with the highest values for Vmax and Km presented the lowest Cmin and root length. The relationships between the Puptake kinetic parameters and the root dimension characters were not uniform for all evaluated genotypes, in accordance to the results found in the present experiment.…”

“…Such variability in maize genotypes, and in other plant species, has been considered as a plant adaptation alternative to the higher or lower soil P availability, since this nutrient moves from soil to root surface by diffusion, a process which depends strongly on physical and chemical soil atributes (Nielsen & Barber, 1978;Baligar & Barber, 1979;Schenk & Barber, 1979a, 1979b1980;Anghinoni et al, 1989;Alves et al, 1998;Ciarelli et al, 1998).…”

“…Genotypes with larger and longer root systems presented also higher dry matter yield of shoot and root (Warncke & Barber, 1974;Schenk & Barber, 1979a, 1979bBaligar & Barber, 1979;Furlani et al, 1984;Furlani, 1988). Significant differences in root surface area of field grown maize genotypes were positively correlated with shoot and root dry matter yield at flowering stage (Schenk & Barber, 1980).…”

Differential response of root morphology to potassium deficient stress among rice genotypes varying in potassium efficiency

“…Manipulating the genotypic differences in crop cultivars to adapt them to adverse soil conditions such as low nutrients status is one of the key strategies for the sustainable intensification of agricultural systems (Yang et al, 2004a). Genotypic differences in K use efficiency have been reported in various crops, e.g., alfalfa (James et al, 1995), snapbean (Shea et al, 1968), soybean (Sale and Campbell, 1987), tomato (Chen and Gabelman, 1995), ramie (Liu et al, 2000), corn (Baligar and Barber, 1979), wheat (Zhang et al, 1999) and barley (Pettersson and Jensén, 1983). Genetic variation also exists in rice in low K soils (Liu et al, 1987;Yang et al, 2003;2004b).…”

Effect of N fertilizer rate and soil pH on N efficiency in corn

“…Corn hybrids differ significantly in N accumulation patterns including: total N uptake, N uptake before silking and N uptake after silking (Rhoades and Stanley, 1981). Genetic differences may be due to root morphology and ion uptake (Baligar and Barber, 1979;Pace and McClure, 1986) or utilization of N in the plant (Anderson et al, 1984;Beauchamp et al, 1976;Moll et al, 1982;Pollmer et al, 1979).…”