PRODUCTION OF HAPLOID PLANTS FROM IN-VITRO CULTURE OF UNPOLLINATED OVULES OF CUCURBITA-PEPO

Ovaries from squash plants (cv. Eskandarani) were picked one day befor e anthesis, and exposed to cold temperature (4 degrees C) for 0, 2, 4 and 8 days. The ovules were cultured on MS medium with 30 g l(-1) sucr ose, 8 g l(-1) agar and supplemented with four concentrations of 2,4-D , i.e., 0.1, 1.0, 5 and 10 mg l(-1). Then the dishes were incubated at 25 +/- 1 degrees C under 16-h photoperiod for 4 weeks. After that ovu les were transferred to growth regulator free MS medium for 4 weeks. D ata indicated that the most plantlets per 100 cultured ovules resulted from the ovule of ovaries without cold treatment, when cultured in MS medium supplemented with 1 or 5 mg l(-1) 2,4-D. The cytological study revealed that one third of examined plants were haploid (2n = x = 20) and the others were double haploid (2n = 2x = 40).