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Differential response of radish plants to supplemental ultraviolet‐B radiation under varying NPK levels: chlorophyll fluorescence, gas exchange and antioxidants
Author(s) -
Singh Suruchi,
Kumari Rima,
Agrawal Madhoolika,
Agrawal Shashi Bhushan
Publication year - 2012
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2012.01589.x
Subject(s) - chlorophyll fluorescence , photosynthesis , raphanus , chlorophyll , stomatal conductance , zoology , chemistry , lipid peroxidation , horticulture , antioxidant , biology , biochemistry
Current and projected increases in ultraviolet‐B (UV‐B; 280–315 nm) radiation may alter crop growth and yield by modifying the physiological and biochemical functions. This study was conducted to assess the possibility of alleviating the negative effects of supplemental UV‐B (sUV‐B; 7.2 kJ m −2 day −1 ; 280–315 nm) on radish ( Raphanus sativus var Pusa Himani) by modifying soil nitrogen (N), phosphorus (P) and potassium (K) levels. The N, P and K treatments were recommended dose of N, P and K, 1.5 times recommended dose of N, P and K, 1.5 times recommended dose of N and 1.5 times recommended dose of K. Plants showed variations in their response to UV‐B radiation under varying soil NPK levels. The minimum damaging effects of sUV‐B on photosynthesis rate and stomatal conductance coupled with minimum reduction in chlorophyll content were recorded for plants grown at recommended dose of NPK. Flavonoids increased under sUV‐B except in plants grown at 1.5 times recommended dose of N. Lipid peroxidation (LPO) also increased in response to sUV‐B at all NPK levels with maximum at 1.5 times recommended dose of K and minimum at recommended dose of NPK. This study revealed that sUV‐B radiation negatively affected the radish plants by reducing the photosynthetic efficiency and increasing LPO. The plants grown at 1.5 times recommended dose of NPK/N/K could not enhance antioxidative potential to the extent as recorded at recommended dose of NPK and hence showed more sensitivity to sUV‐B.