Expression de différents écotypes de gombo (Abelmoschus esculentus L.) au déficit hydrique intervenant pendant la boutonnisation et la floraison

Behaviour of different ecotypes of okra (Abelmoschus esculentus L.) under water deficit during budding and flowering phases. Despite numerous uses and its well known nutritional value, okra is cultivated on very small surfaces, on surroundings of traditional houses and often in dumping ground. To this little interest are added drought, diseases and pests that generate an important reduction of yield, leading okra to play the last roles in agricultural research programs of the country and this, despite the existence of early maturing ecotypes or resistant to some abiotic constraints. The low rate of improved varieties is the proof that it is necessary to develop strategies for participatory breeding programs that take into account farmers selection criteria including genotypes tolerant or resistant to drastic conditions such as water deficit to periods where the plant is expressing its genetic potential. Six ecotypes obtained through participatory plant breeding process in five agricultural districts of the country have been assessed for the tolerance to the drought occurring during the budding and the flowering phases. Results show that water deficit during budding phase has disastrous consequences for okra plants. The yield declines, and also the length, the number and the weight of fruits. Two types of period of flowering phases of okra plant have been observed: the period which intervenes during the accelerated growth phase of the main stem (type 1) and the one which starts once the growth of main stem begins to decline (type 2); this last type is the most frequently met. Water deficit during the phase of budding causes earlier flowering of type 2 plants and leads to delayed flowering of the type 1 plants. The best variables for discriminating okra ecotypes during water deficit are the relative water content (RWC), the length and the number of fruits. Three ecotypes (V1, V3 and V4) are chosen to be used in breeding program of okra for resistance to water deficit.