Although haploids were successfully produced via irradiated pollen technique and anther culture in Cucurbita maxima and Cucurbita moschata, the haploidization efficiency is still low due to genotype dependence. Thus, as an alternative technique, the efficacy of the ovule culture was investigated. Ovules were extracted at different flowering time and then cultured on a solid MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), benzylaminopurine (BAP), thidiazuron (TDZ), and naphthaleneacetic acid (NAA) to induce callogenesis and plant regeneration. The gynogenic response was influenced by the combination of plant growth regulators, genotype and culture time. The medium containing of 4.0 mg/l BAP + 0.05 mg/l NAA + 0.1 mg/l TDZ provided the highest response at anthesis time. Plantlets were rooted and elongated on a solid MS medium supplemented with 0.01 mg/l indole-3-acetic acid (IAA) + 1.0 mg/l BAP. The ploidy observations of 122 plants revealed that 70 plants were haploid, 46 plants were diploid and the others were mixoploid.
Datta S.K. (2005): Androgenic haploids: Factors controlling development and its application in crop improvement. Current Science, 89: 1870–1878.
Diao Wei-Ping, Jia Yuan-Yuan, Song Hui, Zhang Xiao-Qing, Lou Qun-Feng, Chen Jin-Feng (2009): Efficient embryo induction in cucumber ovary culture and homozygous identification of the regenetants using SSR markers. Scientia Horticulturae, 119, 246-251
https://doi.org/10.1016/j.scienta.2008.08.016
Ficcadenti N., Sestili S., Annibali S. (1999): In vitro gynogenesis to induce haploid plants in melon (Cucumis melo L.). Journal of Genetics & Breeding, 53: 255–257.
A. G�mes-Juh�sz, P. Balogh, A. Ferenczy, Z. Krist�f (2002): Effect of optimal stage of female gametophyte and heat treatment on in vitro gynogenesis induction in cucumber ( Cucumis sativus L.). Plant Cell Reports, 21, 105-111
https://doi.org/10.1007/s00299-002-0482-8
Golabadi M., Ghanbari S., Keighobadi K., Ercisli S. (2017): Embryo and callus induction by different factors in ovary culture of cucumber. Journal of Applied Botany and Food Quality, 90: 68–75.
Kurtar Ertan Sait, Balkaya Ahmet (2010): Production of in vitro haploid plants from in situ induced haploid embryos in winter squash (Cucurbita maxima Duchesne ex Lam.) via irradiated pollen. Plant Cell, Tissue and Organ Culture (PCTOC), 102, 267-277
https://doi.org/10.1007/s11240-010-9729-1
Kurtar E.S., Sari N., Abak K. (2002): Obtention of haploid embryos and plants through irradiated pollen technique in squash (Cucurbita pepo L.). Euphytica, 127: 335–344.
https://doi.org/10.1023/A:1020343900419
Ertan Sait Kurtar, Ahmet Balkaya, Mehtap Ozbakir, Tenzile Ofluoglu (2009): Induction of haploid embryo and plant regeneration via irradiated pollen technique in pumpkin (Cucurbita moschata Duchesne ex. Poir). African Journal of Biotechnology, 8, 5944-5951
https://doi.org/10.5897/AJB09.730
Kurtar Ertan Sait, Balkaya Ahmet, Kandemir Dilek (2016): Evaluation of haploidization efficiency in winter squash (Cucurbita maxima Duch.) and pumpkin (Cucurbita moschata Duch.) through anther culture. Plant Cell, Tissue and Organ Culture (PCTOC), 127, 497-511
https://doi.org/10.1007/s11240-016-1074-6
KWACK Soo Nyeon, FUJIEDA Kunimitsu (1988): Somatic Embryogenesis in Cultured Unfertilized Ovules of Cucurbita moschata. Journal of the Japanese Society for Horticultural Science, 57, 34-42
https://doi.org/10.2503/jjshs.57.34
Malik A.A., Cui L., Zhang S., Chen J.F. (2011): Efficiency of SSR markers for determining the origin of melon plantlets derived through unfertilized ovary culture. Horticultural Science, 8: 27–34.
Metwally E.I., Moustafa S.A., El-Sawy B.I. (1998): Haploid plantlets derived by anther culture of Cucurbita pepo. Plant Cell, Tissue and Organ Culture, 52: 171–176.
https://doi.org/10.1023/A:1005908326663
Tantasawat P.A., Sorntip A., Poolsawat O., Chaowiset W., Pornbungkerd P. (2015): Evaluation of factors affecting embryo-like structure and callus formation in unpollinated ovary culture of cucumber (Cucumis sativus). International Journal of Agriculture and Biology, 17: 3.
Plapung P., Khumsukdee S., Smitamana P. (2014): Development of cucumber lines resistant to Cucumber mosaic virus by ovule culture. Journal of Agricultural Technology, 10: 733–741.
Shalaby Tarek A. (2007): Factors affecting haploid induction through in vitro gynogenesis in summer squash (Cucurbita pepo L.). Scientia Horticulturae, 115, 1-6
https://doi.org/10.1016/j.scienta.2007.07.008
Sun S.R., Zhai Q.H., Hu J.B., Chen J.F., Zhang P. (2009): Effects of several physiological factors on embryo formation in unpollinated ovary culture of pumpkin (Cucurbita moschata Duch. ex Poiret). Plant Physiology Journal, 45: 977–980.
