Tissue Cultures of Maize (Zea mays L.): Initiation, Maintenance, and Organic Growth Factors¹

Abstract

Callus from 17 of 23 single crosses and 10 of 17 inbreds of Zea nmys L. was isolated from mature embryos grown on Linsmaier and Skoog RM medium with 15 mg 2,4-dichlorphenoxyacetlc acid (2,4-D) per liter. This callus growth was greatest from the first node of the seedling shoot; occasionally callus growth was observed from the radicle and coleoptile regions. All callus was easily transferred and maintained on media with 2 mg 2,4-D/liter.Genetic variability for callus growth was observed among both single crosses and inbreds. Callus was initiated from 70% of 23 single crosses tested and from only 40% of the 17 inbreds tested. The most rapidly growing cultures were isolated from OhSIA X Os420 which had a 20-to 25-fold fresh-weight increase during a 30-day incubation at 30 C.Cultures maintained on 2,4-D did not require cytokiuins for growth, nor was 2,4-D effectively replaced by idoleacetic acid or ,~-napthaleneacetic acid. Several complex media additives were studied and only 800 mg yeast extract/liter and 200 mg casamino acids/liter individually stimulated significant increases in fresh weight over unsupplemented media. The callus from OhS1A X Os420 has been maintained for 20 months with transfer to fresh media every 30 days (representing 19 subcultures).

Natural and induced variation in tissue culture

“…Physical and morphological changes in unorganized callus A number of different expressions of physiological and morphological changes have been reported in unorganized callus tissue including 1) habituation (loss of exogenous requirement for some growth factor, usually auxin), 2) changes in biochemical sensitivity and requirements, 3) alterations of growth habit, and 4) modifications of cellular constituents. r Variation has also been reported on numerous occasions between plants; GREEN et al (1974) for instance, report remarkable differences among 17 inbred and 23 hybrid corn (Zen map) lines, but this paper will be restricted to reports of variation within individual clones. I) Habituation.…”

A Study of in vitro Regeneration in Relation to Doses of Growth Regulators in Hybrids of Upland Cotton

“…Evidence exists that genetic factors are the main contributors to in vitro response to regeneration in crop plants (Hartmann et al, 1989). Genotypic differences in callus induction and plant regeneration ability have been established in several crops including corn (Green et al, 1974;Tomes and Smith, 1985), oats (Cummings et al, 1976;Rines and McCoy, 1981), barley (Hanzel et al, 1985), triticale (Sharma et al, 1980) and wheat (Ahloowalia, 1982). Genetic control of regeneration has been reported to vary from dominant effect of nuclear genes in corn (Hodges et al, 1986) to additive gene action in wheat and rice (Lazar et al, 1984;Miah et al, 1985;Quimio and Zapata, 1990).…”

Genotypic differences in organogenesis from callus of ten triticale lines

“…Vast differences due to genotype have also been reported in corn (Zea muys L.) in their ability to initiate callus and regenerate plantlets (GREEN & PHILLIPS, 1975 ;GREEN et al, 1974). Callus differentiation was induced by transferring callus onto MS medium containing 0 or 0.1 mg/l 2,4-D. Organogenesis occurred in the callus sub-cultured on both media but with higher frequency in media containing 0.1 mg/l 2,4-D ( Table 2).…”