Effect of Seed Coating and PEG-Induced Drought on the Germination Capacity of Five Clover Crops

Sustained germination-promoting effect of cold atmospheric plasma on spinach seeds

Cold atmospheric plasma (CAP) irradiation exhibits a sterilizing effect without causing thermal denaturation or leaving behind residual toxicants. CAP also has potential applications in various fields, including agriculture, leading to research efforts in recent years. This study investigated the effects of CAP on the seed germination rate of spinach (Spinacia oleracea), which typically has a low seed germination rate. Our results confirmed that irradiation with N2-CAP and Air-CAP significantly enhanced the germination rate of spinach seeds. Notably, we discovered that CAP irradiation promoted germination even in spinach seeds coated with a fungicide (thiuram) and a disinfectant (Captan), which are commonly used. Additionally, we examined whether the interval between CAP irradiation and the subsequent germination-induction treatment influenced the germination efficiency. We found that the germination-promoting effect of CAP on spinach seeds persisted for at least 30 days, demonstrating the high utility and practicality of CAP in the agricultural sector.

The plant protection preparation GZM improves crop immunity, yield, and quality

Lauryl alcohol, a natural compound found in plants and other organisms, is widely used to make surfactants, food, and pharmaceuticals. GZM, a plant protection preparation with lauryl alcohol as its major component is thought to establish a physical barrier on the plant surface, but its physiological functions are unknown. Here, we show that GZM improves the performance of peanut (Arachis hypogaea) plants in both the laboratory and the field. We demonstrate that the treatment with GZM or lauryl alcohol raises the contents of several specific lysophospholipids and induces the biosynthesis of phenylpropanoids, flavonoids, and wax in various plant species. In the field, GZM improves crop immunity, yield, and quality. In addition, GZM and lauryl alcohol can inhibit the growth of some pathogenic fungi. Our findings provide insights into the physiological and biological effects of GZM treatment on plants and show that GZM and lauryl alcohol are promising preparations in agricultural production.

Comparative Analysis of Tolerance to Salt Stress and Water Deficit in Two Invasive Weeds of the Genus Erigeron (Asteraceae)

Erigeron bonariensis and E. sumatrensis are two noxious weeds present in many parts of the world. Their tolerance to salinity and water deficit was analysed at the seed germination stage and during vegetative development. Seed germination was tested in solutions with different concentrations of NaCl and polyethylene glycol (PEG). Growth parameters, photosynthetic pigments, ion accumulation, and antioxidant mechanisms were analysed in plants that were subjected to increasing NaCl solutions, or severe water deficit by completely restricting irrigation. Seed germination was mostly affected by NaCl, but less by PEG in both species. E. bonariensis had a faster germination in all treatments and maintained a higher percentage of germination under the highest concentration of salt applied. Growth responses were similar in the two species, both being more affected by higher salt concentrations than by water deficit. The main differences in the responses of the two species to stress regard K⁺ and proline concentration. K⁺ in roots decreased under salt stress in E. sumatrensis, but remained constant in leaves, whereas in E. bonariensis increased in roots and leaves in salt-stressed plants. Proline concentration increased in all E. bonariensis plants under salt stress, but only in those under the highest salt concentration in E. sumatrensis. The results obtained indicate that the two species are relatively tolerant to water deficit and medium salinity but are susceptible to high NaCl concentrations.

Improved drought tolerance of EMS mutagenized Alfalfa (Medicago sativa L.) mutants by in vitro screening at germination stage

The objectives of this study were to determine drought tolerant novel mutant of alfalfa (Medicago sativa L.) genotypes by screening EMS mutagenized 340675 M₃ seeds at germination stages in the presence of osmotic stress of 35% PEG₆₀₀₀. Root growth assay provided several drought tolerant candidate mutants. Of those, 4 mutants were further evaluated at water deficit conditions applied for 24 days after the first cutting at flowering bud stage. The results revealed that mutants determined as drought tolerant at germination stage were also tolerant to water deficit conditions. Protein content and superoxide dismutase values were found to be higher in all mutants than controls. Ascorbate peroxides, glutton reductase and lipid peroxidase values varied based on the mutant genotype and duration of drought stress. Drought stress significantly changed transcriptional levels of MtP5CS, MtDehyd, MseIF-2, MtRD2 and MsNAC genes. These results indicated that in vitro screening of alfalfa mutant seeds for osmatic tolerance at germination and early seedling growth stages was successfully able to determine the drought tolerant alfalfa mutants which were also tolerant to water deficit conditions after the first cutting at flowering bud stage.

Genetic variation among einkorn genotypes based on gene targeted functional markers and its possible relationship with drought tolerance at seed germination stage

BACKGROUND

Einkorn wheat is one of the first primary genetic resources for discovery of new alleles related to biotic and abiotic stress tolerances for further genetic improvements while it became more popular especially for its native grain status as healthy food resources. Therefore, this study aims to determine germination parameters of 32 local einkorn (Triticum monococcum) genotypes collected from Kastamonu and its vicinity, Turkey under drought stress conditions, and to reveal the genetic relationship of those genotypes based on drought related gene targeted functional markers (GTFMs).

METHODS AND RESULTS

Germination test was conducted at 20 ± 0.5 °C in darkness with randomized complete block design with 4 replications. Seeds placed on double filter papers in a covered glass petri dishes (80 × 15 mm) were treated with polyethylene glycol (PEG₆₀₀₀) with a -0.23 MPa. The final germination percentages (FGPs), speed and span of germination parameters were determined. Drought stress severely worsened all germination parameters measured. The genotypes SG24 and SG12 were the most drought tolerant and sensitive genotypes based on 21.1% and 64.8% of reduction rates in FGPs, respectively. Twelve GTFMs produced a total of 32 bands and 26 of them were polymorphic. The mean polymorphism ratio of the markers and average band per marker were determined as 86.31% and 2.66, respectively. The highest polymorphism information content (PIC) was obtained from AIB1 gene marker (0.875).

CONCLUSIONS

This study revealed that there was a significant genetic variation for drought tolerance levels of local einkorn wheat genotypes at germination stage and drought related GTFMs can be used not only to reveal genetic variation but also to distinguish the drought tolerant genotypes.

Water Stress Inhibits Germination While Maintaining Embryo Viability of Subtropical Wetland Seeds: A Functional Approach With Phylogenetic Contrasts

Wetland species commonly exhibit a range of strategies to cope with water stress, either through drought tolerance or through avoidance of the period of limited water availability. Natural populations provide a genetic resource for ecological remediation and may also have direct economic value. We investigated the effects of drought stress on the seed germination of wetland species. Nineteen species were germinated in four concentrations of polyethylene glycol 6000 (PEG) and were evaluated daily (12-h light photoperiod) or after 35 days (continuous darkness) to determine seed germination under water stress. Germination percentage decreased with an increase in polyethylene glycol 6000 (PEG) concentration, but species' germination response to PEG concentration varied significantly. Seeds recovered their germinability after the alleviation of water stress, but the extent of recovery was species-dependent.