Effect of culture filtrates of Fusarium fungi on oat callus cultures

Abstract

The effect of three concentrations (30, 40 and 50%) of the culture filtrate (CF) of the genus Fusarium fungi (F. sporotrichioides, F. poae, F. equiseti, F. oxysporum) on the growth and development parameters of oat callus culture was evaluated. CF at the callus proliferation stage was used to select somaclonal cell lines with mycotoxin tolerance traits. Prior to this, callusogenesis induction was carried out on the Murashige-Skoog (MS) medium with 3 mg/l 2,4-D and 2 mg/l UIC in the culture of immature embryos of the Tyumensky Golozerny, Tubinsky, Zolotoy Pochatok and Talisman varieties. The material for the experiment was selected from the ears of the plants grown in the summer period of 2016–2018 on the experimental fields in the Krasnoyarsk forest-steppe. Callus size was recorded when transplanted onto the proliferation media (MS + 1.5 mg/l 2,4-D), control and CF-containing media. After 30 days of cultivation, callus growth, signs of necrosis and organogenesis were noted. At the end of the experiment, the number of the regenerants formed was counted. The presence of CF in the proliferation medium already at a concentration of 40% provided a decrease in the proliferative activity and increased the frequency of necrosis by at least 50%. Similar results were obtained at the CF level of 50%. On the media with F. poae CF, the reduction of callus viability reached 60–70%. The calluses that remained viable under these conditions had a frequency of regenerant formation and organogenesis 2–3 times higher than the samples that were not influenced by the selective factor. This is particularly pronounced when F. sporotrichioides CF is added. However, this effect was not observed when F. oxysporum CF was applied. This may be due to the differences in the composition of the mycotoxin complex of this mushroom species from the others used in the study. For further work on the technology of creating oat forms with resistance to mycotoxins of the Fusarium genus fungi, it is assumed to use a level of selective pressure not lower than 40%.