Effect of lowered N, P, K or FE levels on the growth of regenerable maize and soybean callus cultures

Abstract

Regenerable callus cultures of Zea mays L. (maize) and organogenic callus cultures of Giycine max (L.) Merr. (soybean) were grown on media with decreased levels of N, P, K or Fe for three successive transfers on the same concentration. The soybean callus was generally more sensitive than maize to decreased levels of the elements. After three transfers soybean callus growth was completely inhibited with 1/3 of the normal Fe level and was reduced to 6 to 19% of the control growth with 1/30 of the normal medium levels of N, P or K. The maize callus growth was most sensitive to decreases in N with complete growth inhibition with 1/30 of the normal N concentration. When the P, K or Fe concentrations were 1/30 of normal, the maize callus growth was from 18 to 36% of the control. In most cases the growth decreased progressively from the first to the third transfer on the deficient media.

These studies define the N, P, K and Fe concentrations which can be used for screening the maize and soybean callus systems for genotypic differences and for mutants which might show more efficient element usage or uptake. The studies also show that the levels of these elements in the normal culture media cannot be lowered to one‐third the normal level and still maintain optimal growth.

Notes

Present Address: Atomic Energy Authority, Nuclear Research Center, Radiobiology Department, Abou Zaabal 13759, Egypt.