Photosynthesis and Hill Reaction - a Physiological Inquiry into a Thermosensitive Genic Male Sterile (TGMS) Rice Used in Two Line Breeding

摘要

An investigation was carried out to understand the physiological mechanisms of male sterility in rice. The critical sterility temperature and critical stage of thermosensitivity of the selected TGMS (Thermosensitive Genie Male Sterile) line, TS 29 was studied using a Phytotron. Variations in the physiological traits were analyzed at Stage VII of panicle development (Filling phase of pollen, floret and panicle reach full length and colour turns to green). High significant reductions in photosynthetic rate, transpiration rate, hill reaction, sugars and carbohydrate contents were recorded. The high temperature induced male sterility in TGMS line was associated with accumulation of starch and higher diffusive resistance. However a reverse of all the above responses was found in the TS 29 grown under fertility inducing low temperature and in the variety CO 46. The results revealed that some physiological traits play an important role by acting as signals or messengers in response to temperature leading to pollen abortion.