Division of Genetics, Indian Agricultural Research Institute, New Delhi-110 012
*Present address: All India Co-ordinated Wheat Improvement Project, Dr. Sanjaya Rajaram Wheat Laboratory, Main Research Station, University of Agricultural Sciences, Dharwad - 580 005
Porometry is one of the most useful techniques for measuring leaf temperature, leaf relative humidity, stomatal diffusive resistance and transpiration rate. Stomatal behavior under water stress is an important aspect in breeding programme for drought resistance. Lower values for leaf temperature and transpiration rate and higher values for leaf relative humidity as well as stomatal diffusive resistance in maize are considered desirable under moisture stress conditions. In other words negative heterosis for former two characters and positive heterosis for latter two characters would be desirable. While the crosses, viz. Ib 1058 × Ib 1084, Ib 1088 × Ib 1100, Ib 1088 × Ib 1155 and Ib 1100 × Ib 1155 showed highly significant but positive heterobeltiosis for leaf relative humidity and stomatal diffusive resistance. Another cross Ib 1088 × Ib 1000 exhibited significantly negative heterobeltiosis for leaf temperature and transpiration rate and significantly positive heterobeltiosis for leaf relative humidity and stomatal diffusive resistance indicating its usefulness under moisture stress situation.
Heterobeltiosis, porometry, water stress
