Valuable traits of potato (Solanum L.) varieties as influenced by climate change in European Russia

Adaptation of regional assortment of crops to climatic changes necessitates numerical assessment of the observed trends in crop main characteristics and identification of the factors causing this dynamics. In previous research we revealed that valuable traits of cultivated varieties have significantly changed over the last decades. Objective of this research was to summarize our findings on the trends in variability of potato ( Solanum tuberosum L.) valuable traits in the European Russia territory with special regard to climatic factors as causative ones. It was found out that most valuable traits of potatoes depend on temperature under lack or excess of heat. By correlation-regression analysis, the main agroclimatic factors defining development of potato plants in the European Russia are revealed. Increase in the sum of temperatures above 15 °С and earlier date for temperature to exceed 15 °С were those accelerating the most meteodependent phases, the germination and flowering. The long-time observations on phenology, weigh of marketable tuber per plant and starch content in standard varieties were evaluated in the conditions of regional experimental stations of N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). These were Polar Experimental Station (Murmansk region, variety Hibinskii rannii, 1968-2013), VIR Pushkin laboratories (St. Petersburg, varieties Nevskii, 1984-2004; Elizaveta, St. Petersburg 1999-2010), Maikop Experimental Station (the Republic of Adygea, variety Nevskii, 1990-2012). Correlation and regression analysis was used to determine significant climatic factors. It was shown that the most considerable variability of valuable traits occurred under lack (Polar Experimental Station) and excess (Maikop Experimental Station) of heat. In Murmansk region (Polar Experimental Station), planting to flowering period reduced at a decennial rate of 2.4 days, and the temperature sum for this period also decreased decennially by 15.9 °С; in Adygea (Maikop Experimental Station) the decennial rates were 6.6 days and 73.8 °С, respectively. The time from flowering to harvesting increased at Polar Experimental Station and reduced at Maikop Experimental Station. In Maikop region, the temperature sums during planting to harvesting decreased by 253.4 °С per decade. Under contrast climatic conditions, the temperature sums for interphase periods were less stable indexes than their durations. The tuber weight per plant and starchiness grew at Polar Experimental Station, whereas in the Maikop region the potato productivity increased while starchiness decreased. The obtained models allows to forecast further growth of potato productivity in European Russia caused by earlier flowering and extended period from flowering to harvesting. Earlier planting and involvement of more late-ripening varieties can be offered as a measure to update agro technologies for potato cultivation under climate changes in European Russia.