Neeraj KumarManohar lal2016-09-142016-09-142013http://krishikosh.egranth.ac.in/handle/1/76628The effects of low temperature on morpho-physiological traits, antioxidant defense mechanism and protein profile (SDS-PAGE) in three chickpea(Cicer arietinum L.) genotypes i.e. ICCV88503, ICCV96029 and H08-28 differing in their sensitivity to low temperature (<5 o C) was investigated under field conditions. Sampling was done 4 days after exposure (DAE) to low temperature (<5 o C) and control (>5 o C). The water potential (Ψ w) of leaf and osmotic potential (Ψ s ) of leaf decreases in all the three genotypes. ICCV88503 showed more negative values Ψ w of leaf i.e. from -0.69 to -0.88 MPa as compared to -0.66 to -0.84MPa in ICCV96029 and -0.64 to -0.83 in H08-28, respectively. The Ψ s of leaf decreased from -1.78 to -2.06 MPa in ICCV88503 and -1.59 to -2.03 MPa in ICCV96029 and -1.11 to -1.49 MPa in H08-28 after 4 days exposure to low temperature (<5 o C). The proline content of leaf increased significantly from 67.24% in ICCV88503 followed by 44.14% in ICCV96029 and 35.28% in H08-28 as compared to control. Similar increasing trends was observed in the total soluble carbohydrate (TSC) content at 4 DAE (<5 o C). A marked increase in hydrogen peroxide (H2O2 ), lipid peroxidation (MDA) content and relative stress injury (RSI %) was noticed in leaf which was higher in ICCV88503 followed by ICCV96029 and H08-28. More negative values of Ψw of leaf, Ψ s of leaf better accumulation of osmotically active solutes, i.e. Proline and TSC in leaf of ICCV88503 helped in maintaining the higher RWC % of these organs than noticed in ICCV96029 and H08-28. ROS scavenging enzyme of leaves i.e. SOD, CAT and POX specific activity increased maximum in ICCV88503 followed by ICCV96029 and H08-28 after 4 days exposure to low temperature (<5 o C) as compared to control (>5 o C). Higher specific activities of antioxidant enzymes, lower accumulation H 2O2 and MDA content in ICCV88503 than ICCV96029 and H08-28, indicated that these enzymes play a key role in removal of ROS in ICCV88503 better than other two genotypes ICCV96029 and H08-28, thus minimizing the cellular damage caused by ROS under low temperature. Pollen viability (%), in vivo pollen germination and tube growth were also adversely affected with increasing exposure to low temperature (<5 o C) and the effect being most pronounced in H08-28. SDSPAGE revealed more deletion of polypeptide bands in H08-28 than ICCV96029 and ICCV88503 with increasing exposure to low temperature (<5 o C) as compared to control (>5 o C) in leaf. The yield parameters like number of pods plant -1 , number of seeds plant -1 , 100 seed weight and seed weight plant -1 decreased more in H08-28 in early sown condition. Hence, the mechanism of cold tolerance was better in ICCV88503 as compared to ICCV96029 and H08-28 as found from physiological and biochemical traits studied.enOsmotic potential, proline, Hydrogen peroxide, relative stress injury, lipid peroxidation, antioxidant, SDS-PAGE, seed yield.Thesis