Improving the yield and quality of potato tubers through preplant inoculation of healthy hydroponic minitubers with Bacillus subtilis endophytic bacteria

The study was aimed at examining how the preplant inoculation of seed tubers (healthy hydroponic minitubers and super elite reproductive tubers) with Bacillus subtilis 10-4 endophytic bacteria affects the yield and quality (phytonutrient composition) of potato tubers. It was shown that with the inoculation of hydroponic minitubers and super elite tubers, the number of tubers per one potato plant exceeded control by 35%; the yield exceeded control by 68.5 and 16.7%, respectively. In addition, more tubers of marketable quality were obtained in terms of both number and weight as compared to control. The pretreatment of tubers with endophyte had no effect on starch accumulation in the tubers grown from minitubers and super elite reproductive tubers while decreasing the content of reducing sugars by 57 and 11% and promoting a more intensive accumulation of vitamin C (up to 24 and 19%), as well as anthocyanins up to 64 and 67%, as compared to control. The nitrogen content of tubers grown from bacterized minitubers and super elite tubers increased by 15 and 9% as compared to untreated control; phosphorus content, by 42 and 15%; potassium content, by 10 and 7%; copper content, by 13 and 8%; iron content, by 10 and 6%, respectively. The study results indicate that the use of healthy hydroponic minitubers for preplant inoculation provides a more effective yield increase and a significant improvement in the phytonutrient composition of tubers (especially in terms of phosphorus and copper content) as compared to super elite reproductive tubers.