γ-Aminobutyric Acid (GABA) Priming Improves Seed Germination and Seedling Stress Tolerance Associated With Enhanced Antioxidant Metabolism, DREB Expression, and Dehydrin Accumulation in White Clover Under Water Stress

As an important plant growth regulator, the role of γ-aminobutyric acid (GABA) in regulating seeds germination was less well elucidated under water stress. The present study was conducted to investigate the impact of GABA pretreatment on seeds germination of white clover (Trifolium repens) under water deficient condition. Results demonstrated that seeds pretreated with 2μmol/l GABA significantly alleviated decreases in endogenous GABA content, germination percentage, germination potential, germination index, root length, and fresh weight along with marked reduction in mean germination time after 7days of germination under drought stress. In addition, seeds priming with GABA significantly increased the accumulation of soluble sugars, non-enzymatic antioxidants [reduced ascorbate, dehydroascorbic acid, oxidized glutathione (GSSG), and reduced glutathione (GSH)], and enzymes [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathioe reductase, and monodehydroasorbate reductase (MDHR)] activities involved in antioxidant metabolism, which could be associated with significant reduction in osmotic potential and the accumulation of superoxide anion, hydrogen peroxide, electrical leakage, and malondialdehyde in seeds under drought stress. The GABA-pretreated seeds exhibited significantly higher abundance of dehydrin (DHN, 56 KDa) and expression levels of DHNs encoding genes (SK2, Y2K, Y2SK, and Dehydrin b) and transcription factors (DREB2, DREB3, DREB4, and DREB5) than the untreated seeds during germination under water-limited condition. These results indicated that the GABA regulated improvement in seeds germination associated with enhancement in osmotic adjustment, antioxidant metabolism, and DREB-related DHNs expression. Current study will provide a better insight about the GABA-regulated defense mechanism during seeds germination under water-limited condition.

Germination of palm seeds under periods of rehydration

Palm seeds are indicative of being recalcitrant species. Seeds germination for many species, is slow and uneven, even in favorable conditions, often due to the resistance of the woody endocarp that makes them impermeable to water. Most species also have the characteristic of not tolerating the drying process at low moisture levels, thus losing their viability. In view of these considerations, the objective was to evaluate the effect of different periods of rehydration on the germinative process of seeds of royal palm, dwarf palm and jeriva. Seeds were homogenized and immersed in water containing 3 times their volume, with daily replacement. The experimental design used was completely randomized, with 5 treatments (0, 3, 6, 9, and 12 days of rehydration), with 4 replications of 25 seeds. The seeds were placed in transparent “gerbox” plastic boxes containing medium vermiculite as substrate and placed in BOD with a photoperiod of 16-hour of light and their respective optimum temperatures for each species. The number of germinated seeds was counted every 2 days until germination stabilized. The variables analyzed were germination percentage, germination speed index (GSI), average germination time (AGT) and distribution of germination over the days. Rehydration for 3 days increased the germination rate of royal palm seeds. For dwarf and jeriva species, rehydration did not influence the analyzed variables. The GSI and AGT were negatively influenced by the rehydration periods for royal palm. Rehydration prolonged the peak of germination of the studied species.

The Use of Fermented Typha Domingensis Residues by Pleurotus Ostreatus as A bio-Fortification to Control Root Disease on Cucumber Caused by Rhizoctonia Solani

Cucumber is one of important crops and susceptible to root disease caused by Rhizoctonia solani. The study aimed to evaluate the efficiency of two isolates of P. ostreatus (Ah and Ak) and soil treatment with several rates of Typha domingensis residues fermented by P. ostreatus to control R. solani that causes root diseases on cucumbers. In vitro trails, R. solani inhibited significantly by isolate (Ah) as well as redial mycelial growth and the percentage of cucumber seeds germination. In field trails, the number of germinated seedlings was highest at fermented T. domingensis 59.81 compare to control treatment which was 59.81. Disease severity (DS) of root damage was recorded in R. solani and R. solani + Fermented T. domingensis treatments and reached 70.4 and 64.27 respectively.

Investigation and Study of Some Angiospermic Seeds with Special References to Germination and Their Viability in Tribal District Dhar (M.P.), India

An extensive and intensive plant survey in different areas of Dhar district of Madhya Pradesh was carried out in the year 2020-2021. Dhar district is situated in the South-western part of Madhya Pradesh with highly rich floristic biodiversity of plant. The total area of district is 8153 sq. km. of which forest encompasses 1370 sq. km. covering 15.79 percent of its geographical area and covered by Vindhyan scab, Malwa plateau and Narmada basin. The tribal of this area includes Bhil, Bhilala, Barela and Pateliya are the major tribes inhabiting the area and depending on forest. The present study highlights the seeds germination and their viability in different sites of Dhar district of Madhya Pradesh, India. 30 angiospermic seed diversity of higher plants was undertaken. Preliminary study of Seeds germination and their viability survey conducted in the different 11 sites of tribal district Dhar (M.P.), India and reported 29 species under 25 genera and 13 families. Leguminosae is most dominant families with 14 species fallowed by Combretaceae with 4 species and other remains families having one species. It is also noticed that 29 species are used by the ethnic communities of the district for various purposes. In the present communications hindi name, scientific name, family, filed notes and flowering and fruiting periods have been provided. Keywords: Dhar, CAMPA, Seed germination, Seed viability, Narmada River, Malwa plateau, Vindhyan scab

Non-chemical treatments to improve the seeds germination and plantlets growth of sessile oak

The current study aimed to investigate the effect of different treatments applied to sessile oak seeds in order to improve the germination features, development and growth of seedlings. The seeds were subjected to electric field, electromagnetic field and γ rays’ treatments. For the electric field study three distinct voltages (10V, 30V and 50V) and three values of exposure time (15 min., 35 min. and 60 min.) were considered. Displaying the seeds in an electric field for 60 minutes increased the germination rate with 58.89%. The highest value for the seedling’s height was obtained when seeds were exposed for 15 minutes at an intensity of 30V. The interaction between the intensity and the timing showed that treating seeds with 30V for 35 minutes improved significantly the seedlings peculiarities. In regard to the electromagnetic field, the seeds were subjected to a single value of electromagnetic field (B=0,4mT; i=0,680 A) and three values of exposure time: 10 min., 20 min. and 30 min. The sessile oak seeds subjected to the electromagnetic field for 20 minutes induced the highest value of germination percentage (90.00%) and germination index (1.81) and those seeds produced plantlets with high diameter (2.69 mm) and with significant differences towards non-treated plants. For γ rays treatments a dosage of 2 Gy induced the highest value of germination percentage (86.67%), of germination index (2.02); of germination energy (7.7); and of germination speed (7.24). A dosage of 6 Gy decreased the values of the same parameters. Our results showed that a dosage of 2 Gy improved also the growth parameters such as plantlets diameter (2.65 mm) and height (11.25 cm). In short, the physical treatments represent an ecological substitute approach towards the chemical substances presently used to improve seeds germination. Using physical treatments for seeds germination and growth of seedlings might be a harmless alternative for environment.

Sterilizing the Surface of Seeds by Chlorine Gas v1

This protocol sterilizes the surface of seeds for use in clean culture conditions without damaging the seeds germination or growth ability.

SEED METRICS AND INFLUENCE OF TEMPERATURES AND PRE-GERMINATION TREATMENTS ON GERMINATION OF CAESALPINIA FERREA SEEDS

The objective of this study was to evaluate seed metrics, optimum temperature for germination and efficiency of five pre-germination treatments for overcoming dormancy of Caesalpinia ferrea seeds. Seeds were subjected to constant temperatures of 15, 20, 25, 30 and 35°C and to the following pre-germination treatments: nicking with pincers; immersion in water for 24 hours at room temperature; scarification with sandpaper; immersion in caustic soda for 60 minutes; and control (untreated seeds). Germination rate was assessed by germination percentage and germination speed index. A completely randomized design was used with four replicates of 50 seeds each and means were compared by Tukey test at 5% probability. The best germination performance was obtained in the 15-30°C temperature range and by using chemical scarification with immersion in caustic soda, and mechanical scarification by nicking with pincers and by rubbing on sandpaper.