Rice (Oryza sativa
L.) is a major source of carbohydrate and staple food of more than 60% people in the world. It is cultivated in more than 100 countries in the world, but more than 90% of worldâ€™s rice is grown and consumed in Asia. In world's increasing population and to meet the challenge of ever increasing demand for food globally, it is necessary to develop high yielding rice varieties that are tolerant to abiotic stress conditions, such as drought, salinity and cold. The productivity of rice is low in Northern districts of Telangana during Rabi. In this zone quite often the temperature drops below 100
C during December and January resulting in poor growth of seedlings a of rice crop. Germination and seedling establishment are sensitive in rice. Cold temperature during seedling establishment (October to early November) drops to about 10 o
C and such low temperature significantly reduces seedling growth and establishment (Humphreys et al.
, 1996). For breeding cold tolerant rice variety selection of tolerance requires a suitable and cost effective evaluation and screening technology. Breeding cold tolerant varieties in rice is essential to reduce yield loss during winter or Rabi season, for which information on various traits and QTLs contributing to tolerance is necessary. Field Evaluation for cold tolerance during seedling stage under field conditions is limited by environmental variation, which makes it difficult to identify genetically superior lines. Screening for cold tolerance can be done through field evaluation, as well as laboratory screening and QTLs mapping. QTLs mapping was used to confirm the presence and absence of cold tolerant QTLs in the rice genotypes. In this SSR molecular marker was used and many QTLs have been reported which contribute tolerance against cold stress at different stages of growth viz., germination, seedling, booting, bud bursting and reproductive stages etc.