TY - BK AU - Reynolds,M.P. AU - Ageeb,O.A.A. AU - Kholi,M.M.|Martino,D AU - Nagarajan,S. AU - Razzaque,M.A. AU - Rajaram,S. ED - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico) TI - La temperatura del follaje en el periodo posantesis y su relaciĆ³n con el rendimiento SN - 9974-7586-0-2 U1 - 633.1158 PY - 1998/// CY - la Estanzuela (Uruguay) PB - INIA|CIMMYT KW - Canopy KW - AGROVOC KW - Environmental factors KW - Flowering KW - Heat KW - Injurious factors KW - Research projects KW - Yield factors KW - Wheat KW - Yields KW - CIMMYT KW - INIA N2 - The canopy temperature depression (CTD) refers to the cooling effect experience by the leaves when water evaporates from their surface. While the soil humidity has a major influence on CTD, genotypic effects also play a role under high yielding conditions caused by the heat and drought stress. CTD allows an indirect estimate of the stomatal conductance and is an integrative character being influenced by various important physiological processes including photosynthetic metabolism, vapor transpiration and the plant nutrition. The CTD measured on the sunny days, during the grain filling period, frequently demonstrated a strong relationship with the final yield. Under these conditions such a result is produced by the fact that the lines with a high number of grains (potential number of grains, sink) demonstrate their ability to fill the grain through superior photosynthetic metabolism (potential source). In other words, the differences found in the measurement of CTD under correct conditions allow a genetic resolution to visualize the potential yield, which is affected by the balance between potential growth and its partitioning. Quick and easy to measure, the CTD can be an attractive selection tool in the plant breeding. The experiments have been conducted by CIMMYT, in collaboration with the National Programs in India, Sudan, Bangladesh and Nigeria, to evaluate CTD as an early selection tool for tolerance to heat. CTD was measured on populations derived from the F2 bulks and recombinants of the selfed (inbred) lines (RILs) at various locations in Mexico. The results demonstrate that i. The measurement of CTD in bulks in Mexico was significantly correlated with their average performance at 11 other locations internationally ii. CTD was an excellent indicator of which of the bulks produced inbred lines tolerant to heat and iii. the CTD measured in RILs was significantly correlated with their performance ER -