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J Lević

Publications and source records attributed to J Lević.

2 recordsLinked to original sources

[New technology in maize breeding].

Results obtained by several approaches in the application of Biotechnology in maize breeding are reviewed. RFLP technology in the determination of genetic variation; gene transfer by the use of different methods of gene delivery and the determination of gene integration. Three technologies for foreign gene introduction have been applied; injection of plasmid pRT100 neo into archesporial tissue before micro and macro sporogenesis, slightly modified pollen-tube pathway technology and dry seed incubation in plasmid DNA solution. NPTII gene integration was followed by dot-blot and Southern blot analysis of plant DNA of both T1 and T2 plants. Gene expression was analysed by neomycin phosphotransferase activity. Transformed plants contained the selective NPTII gene sequence in an active form. Bacterial gene integration induced several heritable changes of plant phenotype. As an important change, alteration of the flowering time has been used as a criterion for selection and plant propagation to keep transformed progeny. Besides plant genome transformation, endogenous bacteria living in different maize tissue were found. As a perspective approach for biotechnology application in maize breeding biological vaccine construction has been selected. Therefore, antagonistic effect of gram positive bacterial strains to several pathogenic fungi was investigated. Results obtained after in vivo experiments are discussed.

Breeding↗

Formation of alpha- and beta-conidia by Phaeocytostroma ambiguum.

The formation of conidia in Phaeocytostroma ambiguum on different media and conditions was investigated in this study. Carnation leaf agar (CLA) and a 12 h photoperiod (24/18 degrees C) provided excellent conditions for the promotion of rapid formation of both alpha (alpha) and beta (beta) conidia in a number of P. ambiguum isolates. The dimensions of alpha- and beta-conidia amounted to 6.0-19.6 x 3.8-7.5 microm and 6.0-24.9 x 1.1-2.6 microm, respectively. They were produced on short or elongate, simple and branched conidiophores. beta-conidia have not been described before in P. ambiguum. Intermediate conidia were rarely found.

Journal Article↗