Theor Appl Genet (1986) 72, 120-122 9 Springer-Verlag 1986 Plantlet regeneration from glume calli of maize (Zea mays L.) P. Suprasanna, K. V. Rao and G. M. Reddy * Department of Genetics, Osmania University, Hyderabad-500 007, India Received September 12, 1985; Accepted October 21, 1985 Communicated by B. R. Murty Summary. Totipotent callus cultures were established from anther-free glumes of 'Sweet corn', 'Seed corn,' 'DHM 103' and 'DHM 101' on MS medium supple- mented with 1-2 mg/1 2,4-D. The callusing response of the glumes was tested on six different media. Glumes at the uninucleate stage of pollen development callused with a high frequency compared to other stages. Or- ganogenesis was observed in 40% of the cultures on media devoid of hormones. A total of 76 plantlets were regenerated on medium with 0.5-1.0 mg/1 of both IAA and kinetin. Cytological observations in root tips in- dicated a diploid chromosome number (2n = 20). Key words: Maize glumes - Callus initiation - Plantlet regeneration Introduction In addition to genetic manipulation in plants, plant cell and tissue cultures are increasingly being used as important tools in the study of biochemical and molec- ular processes. In maize, early studies dealt with the culture of sugary (La Rue 1949; Straus and La Rue 1954) and non-sugary endosperm (Coe and Reddy 1961). This was followed by reports on callus initiation and maintenance from diploid sources (Mascarenhas et al. 1965), and successful planlet regeneration from scutellar cultures (Green and Phillips 1975) and from mesocotyl sections of germinated immature embryos (Torne et al. 1981). Callus initiation and plantlet regeneration from different explants with variable gene expression, by * To whom correspondence should be addressed utilizing specific genetic markers, may help in under- standing the biosynthesis ofanthocyanin and its regula- tion at the cellular level. The present study mainly deals with the totipotency ofglumes for callus initiation and plantlet regeneration. Materials and methods Four locally grown cultivars of maize namely 'Sweet corn', 'Seed corn', 'Deccan Hybrid Macca 103' and 'Deccan Hybrid Macca 101' were used in the present study. Fresh immature tassels, about 7-15 cm long, enclosed in leaves, were collected and sterilized with 0.1% mercuric chloride for 3 min followed by thorough washing in sterile distilled water. Anthers were removed and the glumes were inoculated onto 6 media: Blaydes (1966); B5 (Gamborg 1968); Linsmaier and Skoog (1965); Murashige and Skoog (1962); Nitsch and Nitsch (1969) and White (t954), supplemented with 2% sucrose and 0.5-4.0mg/1 2,4-dichlorophenoxy acetic acid (2,4-D). The stage of pollen development in the anther, detected by staining with acetocarmine, was used as an index for the age of the glumes. About 5-7 glumes were inoculated per test tube. The total number of explants used varied from 500 to 1,000 for each genotype. Two weeks after callus initiation, callus without any residual explant was subcultured on MS basal medium with 2,4-D. MS basal medium devoid of hormones and medium supplemented with indole 3-acetic acid (IAA) and kinetin 0.5-2.0 rag/1 were used for plantlet regeneration. A total of 150 cultures were incubated under continuous flourescent light (800 1000 lux) at 26___ 1 ~ Results and discussion About two weeks after inoculation, callus initiation was observed at the base of the glume (Fig. 1). Callus formation in some inocula was poor and exhibited rhizogenesis. Glumes collected at the uninucleate stage