A method is presented for mass isolation of metaphase chromosomes and nuclei from plant protoplasts. The isolation procedure was developed for both monocotyledonous and dicotyledonous species using wheat (Triticum monococcum) and poppy (Papaver somniferum) cell cultures. Metaphase chromosomes were isolated from partially synchronized mitotic protoplasts, while for the isolation of nuclei unsynchronized protoplasts were used. Light and electron-microscopic studies revealed that isolated chromosomes and nuclei preserved their intact morphology. A preliminary biochemical study of chromosomal proteins was made by polyacrylamide-gel electrophoresis. Because of the purity and high quantity of isolated chromosomes and nuclei, the given isolation procedure can supply useful material for structural and biochemical studies, and for genetic manipulation.

Grapevine (Vitis vinifera L.) shows morphological plasticity influenced by environmental factors such as radiation and temperature. The effect of row orientation, exposition of leaves and orchard altitude on leaf morphological traits was evaluated. Grapevine cultivar ‘Furmint’ was investigated in this study with the new version of the GRA.LE.D. raster graphic software. The standard OIV (International Organization of Vine and Wine) descriptors were used with additional size parameters. High morphological variability was observed among the leaves collected from 4 different row orientations and 5 levels of expositions. Exposition levels were assigned according to the estimated total radiation collected by leaves at their position. Selected parameters also responded sensitively to changing elevation in the range of 110–289 m. According to the results, traditional leaf morphological investigations performed with machine vision systems may be recommended to reveal significant ecological factors on ampelometric traits.

Nine genotypes of melon (Cucumis melo L.) were selected for the investigation of regeneration. Most of the tested varieties showed regeneration ability on medium containing 0.5 mg l⁻¹ or 1 mg l⁻¹ BA, but following the appearance of shoot buds, only six varieties produced leafy shoots. The effect of combinations of BA with different auxins (IAA, NA, 2,4-D) and ABA in the culture medium on shoot regeneration was tested on cotyledon explants of 'Hógolyó' and 'Hale's Best'. To establish optimal conditions for the adventitious shoot induction six types of seedling-derived explants were prepared from seedlings of four different ages. The best results for shoot forming capacity were achieved with cotyledons followed by decapitated seedlings and hypocotyls derived from 4-day-old seedlings. Cotyledon segments of 'Hógolyó' and 'Hale's Best' were also cultivated on media with different concentrations of IAA and BA supplemented with 0.26 mg l⁻¹ ABA. The highest number of well-formed plantlets was counted for 'Hógolyó' on the medium supplemented with 0.9 mg l⁻¹ BA+ 0.6 mg l⁻¹ IAA+ 0.26 mg l⁻¹ ABA. This is the first report on the in vitro regeneration of 'Hógolyó' from decapitated seedling and hypocotyl explants and of 'JavÍtott Zentai', 'Muskotály', 'Hógolyó', 'Tétényi csereshéjú' and 'Magyar Kincs' from cotyledon explants.

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