Cultivation of anthers of cucumber cultivars (Cucumis sativus L.) in a greenhouse for callus induction

The aim of this research was to investigate the effects of different plant growth regulators and MS culture medium on the characteristics of callus weight, percentage of callus formation and embryogenesis in anther culture of two cultivars of Sina and Negin cucumbers (Cucumis sativus L.).

The experiment was conducted as a factorial in a completely randomized design with three replications. In this research, to determine the stage of growth and development of microspores, male flower buds in the sizes of 0.5 to 2.2 cm were taken from mother plants. For dyeing, the anthers were separated from the buds and placed in stocarman dye solution containing one gram of carmen powder and one hundred milliliters of 45% acetic acid for one day. Then the anthers were crushed on the laboratory slide and the microspores inside them were observed under a light microscope. In the callus induction test, the factors include two cucumber cultivars (Sina and Negin), the combination of different concentrations of BAP (0, 0.7, 0.9 and 1.1 mg/liter) and 2,4-D (0, 0.75, 1 and 1.25 mg/liter). 4 anthers were cultured in each petri dish. After placing the anthers in the culture medium, the lids of the petri dishes were closed and sealed with parafilm, and then they were covered with aluminum foil and placed in the growth chamber at a temperature of 25 ± 2 degrees Celsius in the dark for 2 weeks and the environments They were cultivated once every 2 or 3 weeks.

Cytogenetic experiments showed that 1.5 cm buds containing anthers and microspores in the mononuclear stage are suitable for anther culture. The results of the analysis of the variance of the data showed a statistically significant difference at the level of 0.01 between the interaction effects of genotype and culture medium. Anthers cultured in MS base medium and media prepared with different concentrations of BAP did not show a response and were destroyed after one month of cultivation. The average main effect of cultivars on callus fresh weight after several weeks of cultivation showed that the highest callus fresh weight was obtained in Sina variety. The comparison of the average triple interaction effects of cultivar × BAP × 2,4-D for callus fresh weight in this research has shown that Sina cultivar in MS culture medium contains the growth regulator compound 0.7 mg/liter BAP and 1 mg/liter 2,4 -D has the highest callus fresh weight. By examining the interaction effect of cultivar, auxin and cytokinin, it was found that the highest percentage of callus formation was 100% in both cultivars in environments with the combination of BAP (0.7 and 0.9 mg/liter) with 2,4-D (0.75, 1 and 1.25 mg/L) and in Sina cultivar BAP (1.1 mg/L) with 2,4-D (0.75, 1.1 and 1.25 mg/L). However, the lowest percentage of callus formation was observed in Nagin cultivar in the presence of 2,4-D hormone with a concentration of 1 mg/liter with an average of 33.333%.

In general, the use of growth regulator BAP and 2,4-D in MS culture medium induced callus in anther culture of both cucumber cultivars.