Effect of Salinity on Seed Germination and Seedling Development of Sorghum (Sorghum bicolor (L.) Moench) Genotypes

Abstract

Salinity is one of the most important abiotic stresses that negatively affects plant growth and development around the world. It has been reported that approximately 19.5% of all irrigated land and 2.1% of dry land is affected by salt stress, and these percentages continue to increase. Sorghum, a C4 plant, is the fifth most important cereal in the world. Numerous studies reported that there are high genetic variations in sorghum. These genetic variations can be monitored to search for the most salt-tolerant genotypes. Therefore, the aim of our study was to investigate the responses of ten sorghum genotypes to different levels of salinity. We focused on germination and seedling growth as the most critical stages of plant development. In our research we included germination percentage, germination index, mean germination time, seedling vigor index, seedlings’ shoot and root lengths, fresh and dry seedling weight, and salinity tolerance indices. For data assessment we applied two-way ANOVA, non-metric multidimensional scaling, and hierarchical agglomerative classification. Our results demonstrate that salinity was responsible for 98% of the variation in assessed parameters, whereas genotype effect accounted for only 2% of the documented variation. It can be concluded that seedling traits can be used as a valid criterion for the selection of genotypes with a better tolerance to salinity stress.

Osmotic Stress or Ionic Composition: Which Affects the Early Growth of Crop Species More?

“…The effect of salinity on germination of model plants was also distinct in our study. It is well recognized that salt stress negatively relates to seed germination and vigor [16]. For all plants, a decrease in seed germination was observed in the first days of the experiment.…”

“…Our study focused on three phases of plant development that are responsible for successful crop establishment: germination, seedling emergence and plantlet early growth. It is important to note that germination is the first and one of the most important and sensitive stages of the plant life cycle [10,16,56]. Salinity inhibits germination of plant seeds in one of two ways: at higher salinities germination is stopped without loss of viability, whereas at lower salinities the delay of germination can cause some stress to seeds but does not prevent germination [57].…”

“…The natural brine was taken from salt spring no. 16 Table S1. First, we performed a preliminary experiment.…”

“…These conditions may cause significant reductions in the rate and percentage of germination. Numerous studies have been carried out to determine salinity effects on seed germination and seedling growth [14,[16][17][18]. Under salt stress, seed germination differs between plant species, and significant variation is observed within cultivars [16,19].…”

“…Numerous studies have been carried out to determine salinity effects on seed germination and seedling growth [14,[16][17][18]. Under salt stress, seed germination differs between plant species, and significant variation is observed within cultivars [16,19]. For example, the early seedling stage of rice is among the stages most sensitive to salt stress, so studies on this stage of growth could provide a basis for improving tolerance across the life cycle of the plant [20].…”