Production of doubled haploid plants of Cucurbitaceae family crops through unpollinated ovule culture in vitro

E. Domblides, N. Shmykova, G. Khimich, I. Korotseva, L. Kan, A. Domblides, V. Pivovarov, A. Soldatenko
Genotype accession, cultivation condition of donor plant, stages of embryo sac, composition of induction medium, growing condition in vitro, the choice of regeneration medium, adaptation in vivo, self-pollination of regenerated plants have impact on the efficiency of the DH-technology. DH-plants were obtained from 12 accessions of cucumber, five accessions of winter squash, nine accessions of summer squash, one accession of patty pan squash, and one accession of Styrian pumpkin. For cultivation, it is necessary to use unpollinated ovules containing nearly matured embryo sac just before flower opening. Our own induction medium IМС (induction Medium for Cucurbitaceae) on MSM base with addition of amino acids (100 mg L‑1 proline, 100 mg L‑1 serine and 800 mg L‑1 glutamine), vitamins according to NLN medium, 30 g L‑1 sucrose, 200 mg L‑1 ampilicillin and 7 g L‑1 agar has been developed and successfully used to produce DH-plants. In all accessions results in gynogenesis process were obtained either with TDZ (0.2 or 0.02 mg L‑1) or with 2,4-D (1 or 2 mg L‑1). 0.0001 µM epibrassinolid had positive effect on ovules of summer squash and cucumber. For cucumber ovules it was necessary to expose to 32°C for 7-10 days in dark and then the ovules must have been transferred on fresh medium every 7 days. The ovules of other species were cultivated under light and embryoids were transferred on regeneration MS medium without hormones with 2% sucrose and 3 g L‑1 Phytogel. The yield of embryoids per an ovary was 55, 20, 9, 2, 1 in summer squash, cucumber, winter squash, patty pan squash, Styrian pumpkin, respectively. Cytological observation showed regenerated plants had been doubled haploids after well passed adaptation in vivo. About 30% of plants in all species studied had mixed ploidy.
Domblides, E., Shmykova, N., Khimich, G., Korotseva, I., Kan, L., Domblides, A., Pivovarov, V. and Soldatenko, A. (2020). Production of doubled haploid plants of Cucurbitaceae family crops through unpollinated ovule culture in vitro. Acta Hortic. 1294, 19-28
DOI: 10.17660/ActaHortic.2020.1294.4
gynogenesis, DH-plants, Cucumis sativus L., Cucurbita maxima Duchesne ex Lam, Cucurbita pepo L., medium IMC, embryogenesis

Acta Horticulturae