Krishan Kumar Verma

Developing a mathematical model for variation of physiological responses of Jatropha curcas leaves depending on leaf positions under soil flooding

The effect of soil flooding on photosynthesis, transpiration and stomatal conductance of Jatropha curcas seedlings were studied under natural environmental variables. Soil flooding reduced photosynthesis (PN), transpiration (E) and stomatal conductance (gs) in response to leaf positions of Jatropha curcas plants. Based on the results, we conclude that decrease in stomatal opening and stomatal limitation of photosynthesis, followed by decrease in individual leaf area are the main causes of reductions in carbon uptake of flooded seedlings. A mathematical relationship was successfully developed to describe photosynthesis, transpiration and stomatal response of Jatropha under soil flooding stress.

Phytotoxicity of Fluoride in Guar (Cyamopsis tetragonoloba) Cultivars and its Effect on Morpho-Physiological and Biochemical Traits

This study reports the influence of 0 (1.42), 25, 50, 100, 200 and 400ppm (artificial contaminated water) fluoride on guar (Cyamopsis tetragonoloba L. cultivar local and sadabahar). Seedlings showed decrease in the following morphophysiological and biochemical characteristics: growth, leaf area expansion, SPAD value, chlorophyll fluorescence, yield and antioxidant enzymes, i.e. catalase, peroxidase and superoxide dismutase. At 400ppm F-contaminated irrigation water the average leaf area expansion (∼58 and 45%), shoot-root length (∼45, 46% (local) and ∼23, 54% (sadabahar), SPAD value (∼11, 25, 18% (local) and ∼12, 20, 15% (sadabahar), Fv/Fm (∼8, 11, 16% (local) and ∼6, 9, 12% (sadabahar), catalase (∼21 and 16%), peroxidise (∼42 and 38%) and SOD (∼40 and 39%) in local and sadabahar cultivar, respectively. With increasing F concentrations, growth, physiological and enzyme activity were successively reduced with days and duration of treatment frequency.

Fluoride Inhibits Root Water Transport and Affects Morpho-Physio-Biochemical Characteristics in Guar (Cyamopsis tetragonoloba)

This study focuses on the fluoride contaminated irrigation water on guar (Cyamopsis tetragonoloba) plants to investigate establishment of growth, development and physio-biochemical activity associated with yield characteristics. Long-term fluoride irrigation influence was also recorded using 15-days old established seedlings raised in earthen pots. These fully established guar plants irrigated differentially by using fluoride contaminated water i.e. 1.42 (without contamination of F), 4.02 (Unnao district, naturally contaminated water), 25, 50, 100, 200 & 400 ppm (artificially contaminated water) applied in pots. The fluoride irrigation frequency n=6 (weekly) was maintained and afterwards terminated/harvested. The results showed reduction in morpho-physiological characteristics in relation to without contaminated water (1.42 ppm) of fluoride in both cultivars i.e. HG2–20 and RGC-936. Similar trends were found in enzymatic activity such as catalase, peroxidase and superoxide dismutase in fluoride contaminated irrigation water. The higher loss was observed in 400ppmF as compared to 25, 50, 100 and 200ppm of fluoride contaminated water in both cultivars.