Variation in floral organs in wild populations of Brassica rapa L.
Résumé
In the hermaphroditic plants, floral morphological traits can significantly affect reproductive system by favouring the deposit of self or cross pollen. In the Brassica species, the self-incompatibility mechanism is undoubtedly the main cause of their allogamy; however, floral organs variation can modulate or reinforce the cross pollination level of the plants. In this study, we investigated floral variation among wild populations of Brassica rapa L. from Algeria. We estimated 20 floral traits, including sepals, petals, pistil, stamens and nectaries as well as ovules production. Floral parameters were measured using stereomicroscope. Each flower's ovule number and stigma-anther separation were also quantified under dissecting microscope. We found that all the flower parameters vary among populations or among individuals, especially stigma surface, nectary surface and stigma-anther separation. These three parameters have a coefficient of variation greater than 18,9%. Moreover, the individual variation is different according to the populations. These results suggest that floral morphology may affect pollination efficiency and as a consequence seed production in B. rapa wild populations but with different contributions according to the floral traits