PHOTOSYNTHETIC PIGMENT CONTENT AS A CONSEQUENTAL RESISTANCE SIGN OF POTATO VARIETIES TO HIGH TEMPERATURE AND MOISTURE LACK

Abstract

The aim of the research is increasing potato yield in dry conditions of the Middle Volga region. The research was carried out on the experimental field of the Samara Scientific Research Institute of Agriculture - branch of the Samara Research Center of the Russian Academy of Sciences. The variety testing plant nursery included 28 varieties of potatoes of domestic selection. Udacha, Zhigulevsky, Arosa and Gala breeds were the standard varieties. The plant material was planted out in two replications with 25 plants in each. To determine the content of photosynthetic pigments, extracts were prepared from ten potato leaves of each breed in 100% acetone. Measurements were performed by spectrophotometry. To measure the amount of chlorophyll a , the wavelength of 665 nm, chlorophyll b - 649 nm, and carotenoids - 440 nm were used. The concentration of pigments was determined by using Wettstein formulas. When harvesting, the potato yield was taken into account. The average concentration of chlorophyll a in the studied breeds was 0.92 mg/g, the average concentration of chlorophyll b was 0.62 mg/g, and one of carotenoids was 0.27 mg/g. Potato breeds with high concentration of photosynthetic pigments were identified. A reliable average dependence of the yield of potato breeds on the concentration of chlorophyll b in plants was revealed. The correlation coefficient was 0.42. There is no reliable dependence tested of yield on the concentration of chlorophyll a and carotenoids. Potato productivity is associated with a significant negative relationship with the ratio of both a and b chlorophyll concentrations. The most highly productive varieties were characterized by a high content of two varieties of chlorophyll. A high concentration of chlorophyll b or a minimum ratio of chlorophyll a and b concentrations can be tentatively recommended as a consequential sign for identifying potato breeds that are highly adapted to high air temperature and insufficient moisture.