Morphophysiological Responses: Criteria for Screening Heat Tolerance in Potato

Increasing temperature has become an alarming issue, especially in the context of global food security. Potato, a cool-season crop, is characterized by specific temperature requirements and develops best at about 20°C. The present study was carried out to examine the morphophysiological responses of potato cultivars under high temperature in the experimental field of Tezpur University, Assam, India, consecutively for two years (2013-14 and 2014-15). Seeds of five popular potato cultivars of North East India, viz. Kufri jyoti, Kufri megha, Kufri pokraj (high-yielding cultivar) and Rangpuria, Badami (local cultivar) were sown under three temperature conditions: normal, inside polyhouse and in the early season. Plant height, leaf area index, membrane stability index, chlorophyll stability index and tuber yield were studied. We observed increase in plant height and leaf area index under high temperature environment with a decrease in membrane stability index, chlorophyll stability index and tuber yield. The cultivars Kufri megha and Rangpuria performed better under high temperature with respect to maintenance of morphological alterations leading to lower reduction in yield. Compared to high-yielding potato cultivars, local cultivars were more prone to high temperature. Thus, morphophysiological analysis can be considered as one of the rapid and efficient methods to screen potato cultivars for heat tolerance.