Effects of osmotic and water stresses on root and shoot morphology and seed yield in sunflower (Helianthus annuus L) genotypes bred for Morocco or issued from introgression with H. argophyllus T. & G.

Abstract

The effect of osmotic and water stresses on various morphological traits was studied in eight experimental varieties of sunflower bred for Moroccan conditions or issued from interspecific hybridization with H.argophyllus or H.debilis. Seed yield of the same genotypes was also evaluated under rainfed and irrigated field conditions. Shoot and root growth were significantly reduced by osmotic stress (-0.6 and -1.0 MPa) induced with polyethylene glycol (PEG 6000). Considerable genotype variation was expressed for all traits. Significant genotype by stress interaction was observed for root dry weight and volume as well as seed yield. The morphological traits were not related to seed yield in the correlation and principal component analyses. Four genotypes issued from introgression with H.argophyllus were grouped and distinct from other genotypes according to hierarchical ascending classification. One genotype issued from introgression with H.debilis and three non-introgressed sunflower varieties were found to be very distinct from each other and from those introgressed with H.argophyllus.

Changes in the root proteome of Triticosecale grains germinating under osmotic stress

“…It was observed that higher concentrations of PEG solutions result in more significant inhibition of root elongation. A similar relationship was also noticed in another study (El Midaoui et al 2003).…”

Water Stress Effects on Leaf Growth and Chlorophyll Content but Not the Grain Yield in Traditional Rice (<i>Oryza sativa</i> Linn.) Genotypes of Assam, India II. Protein and Proline Status in Seedlings under PEG Induced Water Stress

“…Inhibition of germination at higher osmotic potential may possibly be attributed to moisture deficit in the seed below the threshold requirement for germination [34]. The reduction in shoot and root growth is important as PEG induced stress affects root volume and root length [10]. The reduction of root volume under induced osmotic stress originates not only from growth inhibitions but also from a loss of turgidity [35].…”

“…Drought effect on seed yield is due to the relation with duration of watering from flowering until physiological maturity [10].…”

Early establishment performance of local and hybrid maize under two water stress regimes

“…Water stress significantly reduced root length in all genotypes, with hybrids being worst affected, decreasing by 33%, on average. Midaoui et al (2003) observed that root length of sunflower was reduced by water stress. Loresto et al (1989), working on rice, found that root length was positively and significantly correlated with drought resistance.…”