18 Indian Journal of Agricultural Sciences 87 (7): 870–7, July 2017/Article Evaluation of Chrysanthemum morifolium varieties for salinity tolerance under hydroponic system HENUKA RAI 1 , D V S RAJU 2 , K V PRASAD 3 , MARKANDEY SINGH 4 , GUNJEET KUMAR 5 , R N PANDEY 6 and LEKSHMY S 7 ICAR-Indian Agricultural Research Institute, New Delhi 110 012 Received : 26 February 2016; Accepted: 4 January 2017 ABSTRACT Salinity tolerance of 22 varieties of chrysanthemum (Chrysanthemum morifolium Ramat.) was studied in National Phytotron Facility, ICAR-Indian Agricultural Research Institute, New Delhi at fve different salinity levels (0, 50, 100, 150, 200 mmol/L). Salt tolerance was identifed by measuring changes of different physiological as well as morphological parameters such as chlorophyll, proline, MSI (Membrane Stability Index), shoot length, root length, dry weight, etc. In the present study, it was found that the amount of chlorophyll a, chlorophyll b and total chlorophyll decreased with increase in the amount of salt concentration. At 100 mmol/L NaCl, the highest total chlorophyll content was found in Pusa Aditya, Haldighati, Lalit, Little Pink and Jaya, whereas lowest was observed in Pusa Sona, Yellow Gold and Himanshu. The rate of reduction in dry weight is dependent on the level of stress and variety. The greatest reduction in dry weight was found under 200 mmol/L NaCl treatment. The MSI reduced up to 47.64% under 200 mmol/L NaCl treatment from 85.65% of control. Reduction in MSI with increase in salinity may be due to high electrolyte leakage from cells of susceptible varieties. An increase in Proline content was observed under salt treated plants as compared to the plants under control. There was signifcant decrease in the root length with increase in the salt concentration. On the basis of modifed standard evaluation score (SES) of visual salt injury, the 22 varieties can be grouped into tolerant, moderately tolerant, susceptible and highly susceptible with most of the varieties falling under the category of moderately tolerant. Little Pink, Lalit, Haldighati and Pusa Aditya falling under the tolerant category while Himanshu and Pusa Sona are grouped under susceptible and highly susceptible category respectively. Key words: Hoagland Solution, Membrane Stability Index, Proline, Salinity 1 Ph D Student (email: raihenuka@yahoo.com), 2 Senior Scientist (email: rajivalex@gmail.com), 3 Principal Scientist (email: kvprasad66@gmail.com), 4 Senior Scientist (email: singh_markendey@yahoo.com), Division of Floriculture and Landscaping; 5 Senior Scientist (email: kumar_gunjeet@yahoo. com), 6 Principal Scientist (email: rnpandey@iari.res.in), Division of Soil Science and Agricultural Chemistry, 7 Scientist (email: lekshmy@iari.res.in), Division of Plant Physiology. Chrysanthemum (Chrysanthemum morifolium Ramat.) is native to China and is one of the most important and popular ornamental worldwide. There are more than 30 000 chrysanthemum cultivars worldwide and about 3 000 are grown in China (Li and Shao 1990, Chen 2001). Area under chrysanthemum cultivation in India is 18.36 thousand ha (NHB 2012-13). It is mainly grown in the states of Andhra Pradesh, Karnataka, Maharashtra and Tamil Nadu. Mostly commercial varieties are susceptible to infection by a number of pests, diseases, and viruses that seriously reduce their ornamental quality (Nagata and deA ´vila 2000, Chung et al. 2001). In addition, abiotic stress such as salt stress, causes serious crop losses, reducing yield by more than half (Boyer 1982, Bray et al. 2000). The problem of soil salinity is due to continuous use of nutrient solution (fertilization) in greenhouse as well as use of reclaimed water for irrigation due to the limited supply of fresh water, especially in arid and semiarid regions of the world. Salinity is a major environmental factor affecting the performance of many crop plants (Munns 2002). Salinity inhibits the growth and reduces the yield of many plants. Reduction in growth of plants under salt stress leads to necrosis of the leaves which leads to the reduction in photosynthetically active area (PAR). Therefore, understanding the physiology of salt tolerance in plants is very important for mitigating the problem of salinity. The general characteristic of saline soils is the occurrence of high concentrations of soluble salts or high exchangeable Na (ESP>15% with pH>8.5) which interferes with the normal plant growth. Because of its increased osmotic potential, the water in saline soils is less readily available to plants leading to a physiological water stress. On the other hand the excessive uptake of Cl - and Na + results in nutrient imbalances and ion toxicity. The restriction of the uptake of chlorine and sodium in the roots and the accumulation of these ions in stems and leaves are therefore, important mechanisms in the tolerance to salt stress which depends https://doi.org/10.56093/ijas.v87i7.71806