Effect of Silicon (Si) Seed Priming on Germination and Effectiveness of its Foliar Supplies on Durum Wheat ( Triticum turgidum L. ssp. durum ) Genotypes under Semi-Arid Environment

Silicon (Si), a nutrient that currently arousing more and more interest from researchers, particularly in relation to water deficit resistance for durum wheat (Triticum turgidum L. ssp. Durum). The present study aimed to explore the effectiveness of Si seed priming and foliar application on durum wheat performances. Thus, a seed bioassay was conducted to assess the effect of three Si levels (15 and 20 mg/l from Na2SiO3H2O (sodium metasilicate powder extra pure) on the germination of 25 durum wheat genotypes under osmotic stress (150 g/l of PEG6000). Under field conditions in semi-arid environment, we evaluated the Si foliar application potential benefits on the physiological and agro-morphological traits. Results showed that Si application, in particular using 15 mg/l, increased significantly the germination percentage (23.96 and 22.37%) the germination index (24.67 and 25.69%), the length of shoot (23.58 and 21.65%) and roots (22.40 and 20.81%), the seedling fresh weight (35.82% and 27.80%), and the seedling vigor index (41.58% and 38.95%) under non-stressed and stressed conditions, respectively. L6 showed the highest value of germination percentage, shoot and root length, and seedling vigor index for all treatments. In semi-arid conditions, Si foliar application enhanced the relative water content (11.66%) and the chlorophyll index (13.60%). In addition, Si increased spike length (8.47%), seed number/spike (19.01%) and grain yield (19.90%) of all durum wheat genotypes. Differential genotypic responses to Si application were observed at both seedling and adult stages.