Genetic analysis of proline concentration under osmotic stress in sunflower (<i>Helianthus annuus</i> L.)

Abstract

Proline concentration has been often suggested as an indicator of osmotic stress. A better understanding of the genetics of this trait is however needed. In the present study, proline concentration has been assessed, together with root and stem growth, potassium, calcium and total soluble sugars concentration and stress injury symptoms, in seedlings of sunflower hybrids and their parents grown under control and osmotic conditions. Proline strongly accumulated with osmotic stress. Its concentration exhibited a large variation among genotypes and was higher in hybrids than in parental lines. A positive association was noted between proline concentration and osmotic adjustment that was reflected in a reduction of osmotic stress induced injury, as showed by the reduced number of calli in the hybrids with higher proline concentration. Broad and narrow sense heritability was higher under osmotic stress suggesting applying the selection in osmotic stress condition. In the control treatment, dominance effects explained most of the genetic variation for proline concentration while under osmotic stress both dominance and additive variance were high. The importance of dominance and additive effects suggested that several genomic regions are controlling this trait. Good general combiners, presumably carrying positive additive alleles affecting proline concentration, were identified.

Effect of Sulfadimethoxine, Oxytetracycline, and Streptomycin Antibiotics in Three Types of Crop Plants—Root, Leafy, and Fruit

“…The highest proline accumulation occurred at the highest VAs concentration of 100 mg kg −1 . As reported in a previous study, the accumulation of proline in Medicago polymorpha and Medicago ciliaris under NaCl stress, was the greatest at the highest NaCl concentration of 100 mM [34]. Proline contributes to osmotic adjustment, stabilization, and protection of membranes integrity and macromolecules from the damage as a ROS scavenger [35,36].…”

Morphological and biochemical changes in response to salinity in sunflower (Helianthus annus L.) cultivars

“…Proline concentration has been often suggested as an indicator of osmotic stress (Khalil et al, 2016). Proline accumulation under salt stress has been correlated with salt tolerance (Mansour and Ali, 2017).…”

“…However, our result showed that there is a negative relationship of morphological traits (plant height, leaf area, fresh weight, dry matter and water contents) with proline accumulation in all sunflower cultivars (Table 6). Khalil et al (2016), stated that the negative relationship with morphological traits indicated that proline concentration may not be related with enhancing growth in sunflower but could increase survivability under stress contributing to the osmotic adjustment, and could participate in rapid recovery.…”

Proline content of sunflower cultivars in the Brazilian semiarid region

“…A number of studies regarding agronomic traits of sunflower are reported (Rauf, 2008); however, only few studies are conducted under drought stress (Casadebaig et al, 2008;Ghaffari et al, 2012;Pourmohammad et al, 2014;Khalil et al, 2016), and even less ones on drought under field conditions (Alza & Fernandez-Martinez, 1997). Most studies include only one or two cultivars.…”