Effect of Varying Media Formulations on Microtuberization in the Potato Cultivars

Abstract

In vitro microtuberization represents the transitory phase between in vitro multiplication of a healthy plant material and field growing stage. Microtubers are small in size, less in weight, having similar morphology and biochemical features with traditional tubers and are produced in vitro in a plethora of different growing systems with varying environment and media constituents. Microtubers offer a lot of advantages to storage, transport and mechanization and are used as in basic and strategic research covering the areas of plant metabolism, germplasm selection and molecular farming. Microtuberization is a complex physiological process regulated by many factors like genotype of the cultivar and environmental conditions. So, its response varies from cultivar to cultivar. In the present study, we mainly focussed on some of our Indian potato cultivars viz. Kufri Chipsona 1, Kufri Chipsona 2, Kufri Pukhraj and Kufri Ashoka along with an exotic variety Desiree, which are suitable to our agro-climatic zones. Various media formulations were used to study the effect of sucrose and chloro choline chloride (CCC) on different cultivars in the same environmental conditions. In the media containing 8% sucrose concentration along with benzyl amino purine (BAP) and CCC, the potato cultivar Kufri Pukhraj showed good response, Kufri Ashoka and Kufri Chipsona 1 showed average response whereas, Desiree and Kufri Chipsona 2 showed poor response with respect to average tuber weight, length and tuber number per plantlet. In 6% sucrose, again the cultivar Kufri Pukhraj showed good response, Kufri Chipsona 1 and Kufri Ashoka showed average response whereas, Kufri Chipsona 2 and Desiree showed poor response. In 4% sucrose, the cultivars Kufri Pukhraj and Kufri Ashoka showed maximum response Desiree and Kufri Chipsona 2 showed average response while, Kufri Chipsona 1 showed poor response. Early tuber induction was observed in the cultivars Kufri Pukhraj and Desiree while late tuberization was observed in the cultivar Kufri Chipsona 1. Similarly, the effect of CCC on microtuberization of these cultivars was also studied. In media containing 8% sucrose and 500 mg/L CCC, the best results were shown by the cultivar Kufri Pukhraj, followed by Kufri Ashoka and Kufri Chipsona 2 whereas, Kufri Chipsona 1 and Desiree showed least response. In media containing 8% sucrose and 250 mg/L CCC, the best response was shown by Kufri Ashoka and Kufri Pukhraj followed by Desiree and Kufri Chipsona 1 while, Kufri Chipsona 2 showed least response. Kufri Chipsona 1and Kufri Pukhraj showed early tuber induction while, Kufri Chipsona 2 showed late tuber induction in all CCC concentrations. When both CCC and BAP were omitted from the tuberization media containing only sucrose, the cultivars Kufri Pukhraj and Kufri Chipsona 1 showed best response in 8%, 6%, 4% sucrose whereas Desiree showed good response in 8% and 6% sucrose, followed by Kufri Chipsona 2 and least response was shown by Kufri Ashoka. Early tuber induction was seen in case of Desiree and Kufri Pukhraj whereas, Kufri Chipsona 1 and Kufri Chipsona 2 showed late response to tuber induction. As a whole, the cultivar Kufri Pukhraj showed best performance in terms of tuber yield and size, as compared to other cultivars when grown at various media formulations.