XVI International Botanical Congess

Hybrid wheat obtention requires a transformation in flower behaviour from self to cross-fertilization. Male sterile plants can be obtained by the use of a Chemical Hybridizing Agent (CHA). The efficiency of CHA foliar application depends largely on the vegetative state and is influenced by edaphic and climatic factors. In order to obtain hybrid seeds, male-sterile plants must be pollinated by a second variety, shedding a great number of viable pollen grains. Hybrid seed production requires an adaptation of both parents : female line receptivity, pollen production by male line, synchronous flowering. Male and female plants are sown in alternate strips, hybrid seed set results from the harvest of the female strip and is highly variable. Germination performace of hybrid seed is commonly improved, but different paramaters can influence seed purity. Hybrid wheat development is linked to the profitability of the production system and the reliability of seed production.