The contribution of green plant parts to grain filling of durum wheat under water deficit
Résumé
The grain developing and filling are considered as key step for durum wheat yield (Triticum turgidum), under water deficit. The present work aimed to evaluate the contribution of green organs to grain filling. Excision and shading the green organs were performed on five genotypes contrasted for their reaction for the water deficit. The experiment was conducted under three water treatments, 100%, 60% and 30% of field capacity. The contribution of current photosynthesis and reserves remobilization in the grain filling, were obtained by excision and shading of plant organs. The results showed that the contribution of each green organ to grain filling was dependent greatly on genotype and also the water supply. The photosynthetic activity of ear and reserves re-mobilization, contributed the largest rates in grain filling. This contribution, mainly the remobilization, increased more in most genotypes under the water deficit. The contribution rate of the current photosynthesis of the flag leaf and awns proved more effective in well-watered conditions. The reserves translocation resulting from the photosynthetic activity of the spike’s neck for grain filling were greatly dependent on the genotypes where it was higher in ACSAD1361 and Waha. However, it rose with increasing water deficit.