EFFECT OF GENOTYPE, SOURCE TISSUE AND MEDIA COMPOSITION ON CUCUMIS AND CUCURBITA PROTOPLAST ISOLATION AND REGENERATION

The aim of this work was to examine the effect of accession or genotype, source of protoplasts and culture technique on protoplast culture. Protoplasts were isolated and cultured from Cucumis anguria (3 accessions), C. melo (6 accs.), C. metuliferus (4 accs.), C. sativus (4 accs.), C. zeyheri (4 accs.), Cucurbita argyrosperma (2 subsp.), C. ficifolia, C. pepo (3 subsp.), C. maxima subsp. andreana, and C. moschata. Young leaves, hypocotyls, growing apices and calli were used as a source of protoplasts. Callus cultures were derived from young leaves, cotyledons and hypocotyls cultured on three media: MSC (MS + NAA/BAP 2.5/1.0 mg/L), DB1 (2,4-D/BAP 1.0/1.0 mg/L) and EM (2,4-D/BAP 1.0/0.1 mg/L). Protoplasts were cultured either in liquid or agarose-solidified LCM medium (NAA/2,4-D/BAP 1.0/0.5/0.5 mg/L). For some genotypes CML medium (NAA/IPA 4.7/2.8 mg/L) was used. The most suitable genotypes for mesophyll protoplast culture were: C. anguria var. longaculeatus, C. melo MR-1 (Ames 8578), C. melo cv. Charentais D 132, C. metuliferus (CZ 09-H41-0587), C. sativus (line SM-6514, CZ 09-H39-0768); cv. Borciagovskij (CZ 09-H39-056) and C. zeyheri (CZ 09-H41-0196; CZ 09-H41-0595). Hypocotyls and growing apices were not suitable. The most suitable accessions for callus protoplast culture were Cucumis melo MR-1 (CZ 09-H40-600), C. melo (CZ 09-H40-1114) and the most suitable explant was hypocotyl. The most suitable medium was MSC. Callus protoplasts had lower regeneration ability than mesophyll protoplasts. LCM medium without agarose was more suitable for protoplast culture than other versions.