Screening of sunflower (Helianthus annus L.) accessions under drought stress conditions, an experimental assay

Abstract

Drought is the major abiotic stress that limits the crop production at drastic level. Screening of tolerant accessions from available germplasm is the basic step in plant breeding. Sunflower is becoming popular and major oilseed crop in world but unfortunately it is drought sensitive. Screening in field has uncertainties due to the uncontrolled conditions, interaction of biotic and abiotic stresses and variability in environmental factors. Response of the sixty sunflower accessions to drought stress at germination and seedling stage was examined by using polyethylene glycol (PEG-6000) as drought simulator under laboratory. Normal and drought stress treatments i.e. T 1 = zero (control), T 2 =-1.33 MPa and T 3 =-1.62 MPa were developed by dissolving 0, 15 g and 20 g Polyethylene Glycol (PEG-6000) in 100 mL distilled water and a completely randomized design with three replications were used. Promptness, germination, seedling height, fresh weight, dry weight and stress indexes were determined to evaluate the response of sunflower accessions under normal and PEG simulated drought stress treatments. Principal component analysis was used to select the drought tolerant and sensitive accessions. The accessions 017583, A-75, A-79, 017592, G-33, A-48, A-23, G-61, HBRS-1 and 017566 were selected as drought tolerant while, CM-621, 017577, HA-124, HA-133, HA-342 and HA-341 were as drought sensitive. This study may be helpful for the comparison of drought indexes in a controlled experimental assay and for the identification of drought tolerant sunflower cultivars to be used in further breeding programs.

Multiple genomic regions influence root morphology and seedling growth in cultivated sunflower (Helianthus annuus L.) under well-watered and water-limited conditions

“…Thus, despite the genetic bottleneck that occurred during the domestication of sunflower [ 59 , 89 , 90 ], cultivated sunflower appears to have retained considerable functional variability. The observed reduction in aboveground growth under osmotic stress ( Table 1 ) was consistent with previous work in sunflower (e.g., [ 91 – 93 ]) and other species (e.g., [ 94 – 96 ]) where osmotic stress was induced using PEG. In partitioning root morphology into upper vs. lower root sections, we observed a shift from higher TRL allocation (i.e., more lateral root growth near the soil surface) under control conditions towards reduced TRL allocation values (i.e., increased TRL deeper in the soil) under stress ( Fig 1 ).…”

Heterotic Effect of Different Cytoplasmic Combinations in Sunflower Hybrids Cultivated Under Diverse Irrigation Regimes

“…The experiment was conducted over two years over the two environments (normal irrigated and water stress). Water stress was created by withholding the irrigation throughout anthesis and soft dough phases of crop growth [39]. In the normal irrigation environment, six irrigations (recommended by PAU for cultivation of sunflower in the Punjab region) were applied during the crop season, whereas in the water stress environment, only two irrigations were applied during the crop season to create water stress for both years.…”

Characterization for Drought Tolerance and Physiological Efficiency in Novel Cytoplasmic Male Sterile Sources of Sunflower (Helianthus annuus L.)

“…There were 20 plants (10 in each plot) of every parent and their hybrids in each replication. Similarly, the nearby field was chosen for the drought screening trial, the same set of experiment was repeated with a different water regime by withholding irrigation during anthesis and soft dough stages of crop growth [66]. The same experiment was repeated in the February 2012 for the second-year evaluation trial.…”