Nitrosomethylurea induced streptomycin resistance in Lycopersicon esculentum Mill
Rao, A.V.; JayaSree, T.; Ramesh, M.; Pavan, U.; Sadanandam, A.
Indian Journal of Experimental Biology 38(6): 617-620
2000
ISSN/ISBN: 0019-5189 PMID: 11116537 Document Number: 520918
High frequencies of streptomycin resistant variants of Lycopersicon esculentum were isolated on selective shoot regeneration medium supplemented with 0.5 mg IAA, 1.5 mg zeatin and 500 mg streptomycin sulphate/litre. Non-mutagenized (controls) and NMU [N-methyl-N-nitrosourea] treated cotyledons were placed on shoot regeneration medium supplemented with antibiotic streptomycin. Resistant shoots appeared at a high frequency in mutagenized cotyledons, whereas in controls morphogenesis was suppressed, accompanied by bleaching. Shoot regeneration occurred from the nodular tissues developed at the cut ends of cotyledons. Resistant shoots developed into complete plantlets on rooting medium containing selective concentration of antibiotic. Stability of streptomycin resistance was confirmed by leaf assay and reciprocal crosses between streptomycin-resistant and sensitive plants.