Chlorophyll stability index (CSI): its impact on salt tolerance in rice.

Salinity is a major constraint to successful agriculture in the arid and semiarid tropics. High-yielding varieties do not perform well under salt stress conditions. Thus, there is a need to develop special varieties that can perform well under saline conditions. The area with potential saline soil is about 20 million ha, and about 7 million ha are severely affected by salinity. This constitutes a major part of problem soils in India. Irregular monsoon and irrigation in red soil cause salinity problems in large areas. The chlorophyll stability index (CSI) is an indication of the stress tolerance capacity of plants. A high CSI value means that the stress did not have much effect on chlorophyll content of plants. A higher CSI helps plants to withstand stress through better availability of chlorophyll. This leads to increased photosynthetic rate, more dry matter production, and higher productivity. This indicates how well chlorophyll can perform under stress.