Effects of Low Temperatures on Enzyme Activity, Chlorophyll and Ion Contents in Common Bean Genotypes

Abstract

Low temperatures slow down plant growth and development and generate physiological damages on plants. Metabolism of largely produced and consumed common bean (Phaseolus vulgaris L.) plants decelerates at temperatures below 15 degrees C. This study was carried out at Van Yuzuncu Yil University in Van province of Turkey with limited vegetation period due to its cold climate in winter. In this study, the bean plants were subjected to low temperature stress and catalase (CAT), super oxide dismutase (SOD), ascorbate peroxidase (APX) enzyme activities, malondialdehyde (MDA), chlorophyll-a, chlorophyll-b and total chlorophyll, K, Ca, and Mg ion contents of low temperature stress-tolerant Yakutiye and C30 and low temperature stress-sensitive Zulbiye and C13 bean genotypes were measured on 25th, 30th, 35th and 40th days of low temperature stress. Four bean seeds were sown in 2-liter pots filled with 2:1 peat:perlite mixture as to have 2 plants in each pot. The pots were irrigated with Hoagland nutrient solution. Low temperature stress plants were sown on 15th of March with low outdoor temperatures. In control group, been seeds were sown on 25th of April and plant samples were taken in again 5-day intervals in 4 periods (25th, 30th, 35th and 40th days of growth). Significant differences were observed in enzyme activities, chlorophyll contents and ion contents of low temperature-tolerant and sensitive bean genotypes in 4 measurement periods.