Chrysanthemum Research Paper

Chrysanthemum (Chrysanthemum morifolium Ramat.) belongs to the family Asteraceae and is native to China. The name chrysanthemum is derived from Greek word “Chryos” which means golden and “anthos” means flower. The genus Chrysanthemum forms a polyploidy complex with ploidy number ranging from 2x to 25x with basic chromosome number (x) 9. It also known as “Autumn Queen” and “Queen of the East”. Chrysanthemum is one of the leading cut flower in the international market and ranking 2nd in global cut flower trade after rose. C. morifolium is a hybrid arising out of complex interspecific crosses in which number of elemental species have been involved viz., C. sinense, C. indicum, C. japonicum, C. ornatum, C. satsumense and C. boreale. It has earned

In India, it is also equally popular as both cut flower as well as potted plants. It is mainly cultivated in the states of Andhra Pradesh, Karnataka, West Bengal, Punjab, Bihar, Maharashtra and Tamil Nadu and comprises as an important component of floricultural export. However, most of the commercial varieties are susceptible to infection by a number of insects, pathogens, and parasites which seriously reduce their ornamental quality (Nagata and deA ´vila 2000; Chung et al., 2001) as well as their vase life too. 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 regular use of nutrient solution (fertilization) in greenhouse as well as by use of reclaimed water for irrigation purpose due to the limited supply of fresh water, especially in arid and semiarid areas of the world. In the present context, salinity is becoming a major challenge in India where availability of good quality water is an important issue in wake of increasing population and urbanization. Moreover the availability of good quality land is a major concern when pressure on land is increasing due to the intensification of cropping system in the context of food

Salinity inhibits the growth and reduces the yield of many plants. The reduction in growth of plants under salt stress is due reduction in absorbance of photosynthetically active Radiation (PAR) by leaves, which has adverse consequences on the quality of produce. It imposes both osmotic and ionic stress in number of crop plants. Therefore, understanding the physiology of salt tolerance in plants is very important for mitigating the problem of salinity. Under saline conditions, the occurrence of high concentrations of soluble salts or high exchangeable sodium (ESP>15% with pH>8.5) interferes with the growth and development process. The water in saline soils is less readily available to plants due to increased osmotic potential, leading to a physiological water stress. On the other hand, the excessive uptake of Na+ and Cl- results in nutrient imbalance and may cause ion toxicity in plants. Due to salt stress, there will be production of reactive oxygen species which cause oxidative damage and ultimately leading to cell injury (Sairam et al., 2002). Salt stress also cause reduction in protein synthesis and nucleic acid metabolism (Boyer, 1965; Kaiser,1987), decrease in uptake of K+, Mg2+, Ca2+ followed by decrease in growth at higher sodium concentration (Poonia,1972). There will be accumulation of proline, a compatible