Effect of Pre-Sowing Treatments on Mamalis (Pittosporum pentandrum Blanco Merr.) Seeds Germination under Nursery Condition

Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H2SO4) for 5 minutes, hilar removal, and a control in which the seeds were sown without being treated. The experiment was laid out in the Completely Randomized Design (CRD) with four replicates and 60 seeds per treatment. Seeds were sown in an improvised Seedbox in October 2019. Germination was monitored daily for one month. The results showed that Mamalis seeds treated with lukewarm water have the earliest germination of twelve days, with a germination percentage of 66.67%. The germination rate of another treatment ranges from 0 - 44 percent, compared to 45 percent for the control treatment. It seems prudent to conclude that to enhance the vegetative propagation methods is to soaking in warm water at 37.5˚C for 2 hours could provide the best growth.

GABA Enhances Thermotolerance of Seeds Germination by Attenuating the ROS Damage in Arabidopsis

Seeds germination is strictly controlled by environment factor such as high temperature(HT)through altering the balance between gibberellin acid(GA)and abscisic acid(ABA).Gama-aminobutyric acid(GABA)is a small molecule with four-carbon amino acid,which plays a crucial role during plant physiological process associated with pollination,wounding or abiotic stress,but its role in seeds germination under HT remains elusive.In this study we found that HT induced the overaccumulation of ROS,mainly H_(2)O_(2) and O_(2)^(-),to suppress seeds germination,meanwhile,HT also activated the enzyme activity of GAD for the rapid accumulation of GABA,hinting the regulatory function of GABA in con-trolling seeds germination against HT stress.Applying GABA directly attenuated HT-induced ROS accumulation,upregulated GA biosynthesis and downregulated ABA biosynthesis,ultimately enhanced seeds germination.Consistently,genetic analysis using the gad1/2 mutant defective in GABA biosynthesis,or pop2-5 mutant with high endogenous GABA content supported the potential function of GABA in improving seeds germination tolerance to HT through scavenging ROS overaccumulation.Based on these data,we propose that GABA acts as a novel signal to enhance thermotolerance of seeds germination through alleviating the ROS damage to seeds viability.

The BHLH Transcriptional Factor PIF4 Competes with the R2R3-MYB Transcriptional Factor MYB75 to Fine-Tune Seeds Germination under High Glucose Stress

It is known that the high level of sugar including glucose suppresses seed germination through ABA signal.ABI5 is an essential component to mediate ABA-dependent seed germination inhibition,but underlying mechanism needs more investigation.Previous study demonstrated the PIF4 activated the expression of ABI5 to suppress seed germination in darkness.Here we reported that PIF4 also mediated the seed germination inhibition through ABI5 under high concentration of glucose treatment.Furthermore,we found that PIF4 interacted with PAP1,the central factor to control anthocyanin biosynthesis.Such interaction was confirmed in vitro and in planta.Biochemical and physiological analysis revealed that PAP1 bond the promoter of ABI5 to suppress its expression,thus enhanced seed germination under high concentration of glucose treatment.Specially,PAP1 competed with PIF4 to antagonize the activation of PIF4 on ABI5 expression,thus promoted seed germination under high glucose treatment.Given these,we uncover a novel role for PIF4 and PAP1 in controlling seed germination under high glucose treatment,and reveal their antagonistic mechanism by which coordinates ABI5 expression to control seed germination in response to the glucose signal.

S-Nitrosoglutathion Reductase Activity Modulates the Thermotolerance of Seeds Germination by Controlling ABI5 Stability under High Temperature

Seed germination or dormancy status is strictly controlled by endogenous phytohormone and exogenous environment signals.Abscisic acid(ABA)is the important phytohormone to suppress seed germination.Ambient high temperature(HT)also suppressed seed germination,or called as secondary seed dormancy,through upregulating ABI5,the essential component of ABA signal pathway.Previous result shows that appropriate nitric oxide(NO)breaks seed dormancy through triggering S-nitrosoglutathion reductase(GSNOR1)-dependent S-nitrosylation modification of ABI5 protein,subsequently inducing the degradation of ABI5.Here we found that HT induced the degradation of GSNOR1 protein and reduced its activity,thus accumulated more reactive nitrogen species(RNS)to damage seeds viability.Furthermore,HT increased the S-nitrosylation modification of GSNOR1 protein,and triggered the degradation of GSNOR1,therefore stabilizing ABI5 to suppress seed germination.Consistently,the ABI5 protein abundance was lower in the transgenic line overexpressing GSNOR1,but higher in the gsnor mutant after HT stress.Genetic analysis showed that GSNOR1 affected seeds germination through ABI5 under HT.Taken together,our data reveals a new mechanism by which HT triggers the degradation of GSNOR1,and thus stabilizing ABI5 to suppress seed germination,such mechanism provides the possibility to enhance seed germination tolerance to HT through genetic modification of GNSOR1.

Effect of Food Waste Compost (FWC) and its Non-Aerated Fermented Extract (NFCE) on Seeds Germination and Plant Growth

The aim of this study was to investigate the effect of the food wastes compost (FWC) and its non-aerated fermented extract (NFCE) on seed germination and growth of tomato (Solanum lycopersicum L.), watercress (Nasturtium officinale), chili pepper (Capsicum annuum), peas (Pisum sativum L.), chickpea (Cicer arietinum) and beans (Vicia faba) under greenhouse conditions. The FWC and NFCE were physico-chemically and microbiologically characterized. The NFCE effect was evaluated on tomato, watercress, and chili pepper seeds germination and seedling growth. However, for leguminous, pea, chickpea and bean seedlings, the FWC amended soils and irrigated with NFCE were tested for plants growth. The results of FWC analyses revealed that FWC has neutral pH, low EC and C/N ratio, with fertilizing elements (N, P, K and Mg) and lack of phytotoxic effect. The NFCE was characterized by low EC and relatively high carbon content (COD = 9700 mg/l), and intense microbial activity, notably mesophilic bacteria. Therefore, in fermented compost extract, mesophilic bacteria were increased by 225, yeasts by 25 and molds by 10 times compared to those of the investigated compost. In greenhouse, the diluted NFCE increased significantly (p< 0.05) germination and growth of the tested seedlings. Used alone, the FWC amended soil or the NFCE irrigated soil, improved the growth of tested seedlings. The use of soil amended with compost and irrigated by fermented compost extract decreased significantly the growth of the same experimented seedlings. Therefore, the FWC and its fermented extract were a suitable substrate for germination and growth of the studied seeds.

The Influence of Low Frequency Electromagnetic Field （LF EMF） on the Agricultural Crops Seeds Germination

This research is about changing rate of seeds germination by low frequencies electromagnetic field. The method of resonant frequencies to increase seeds germination were developed and patented by authors of this research. The idea of the means is to research a technique to changing a capacitor component of full resistance for extracts of wheat and sunflower seeds under the influence of low frequency electromagnetic field （LF EMF）. After the green sprouting experimentin cups of Petri, it was found that most frequencies found by this method are good, and the best results increasing germination of wheat of a grade Krasnodar 99 were after treatment with 31 Hz, for sunflower of a grade Buzuluk 16 Hz.

Pectin methylesterase inhibitors GhPMEI53 and AtPMEI19 improve seed germination by modulating cell wall plasticity in cotton and Arabidopsis

The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.

Arginine promotes seed energy metabolism,increasing wheat seed germination at low temperature

Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly important for achieving high and stable wheat yields.In this study,Tongmai 6(insensitive)and Zhengmai 113(sensitive),which have different low-temperature sensitivities during germination were treated with low temperature during germination.The transcriptome,metabolome and physiological data revealed that low temperature decreased the germination rate,downregulated the expression of a large number of genes involved in regulating glycometabolism,and inhibited carbon,nitrogen(especially amino acids)and energy metabolism in the seeds.Arginine content increased at low temperature,and its increase in the low-temperature-tolerant variety was significantly greater than that in the sensitive variety.Arginine priming experiment showed that treatment with an appropriate concentration of arginine improved the seed germination rate.The conversion of starch to soluble sugar significantly increased under exogenous arginine conditions,the content of key metabolites in energy metabolism increased,and the utilization of ATP in the seeds increased.Taken together,arginine priming increased seed germination at low temperature by relieving inhibition of seed carbon and nitrogen metabolism and improving seed energy metabolism.

Genome-wide association study reveals that JASMONATE ZIM-DOMAIN 5 regulates seed germination in rice

Seed germination is a complex trait regulated by multiple genes in rice.However,the regulators of rice seed germination have yet to be sufficiently determined.Here,a quantitative trait locus(QTL)for rice seed germination was identified in a genome-wide association study.The candidate gene JASMONATE ZIM-DOMAIN 5(OsJAZ5)of the QTL was verified that positively regulates seed germination.OsJAZ5 regulation of seed germination involves an OsABI3-mediated abscisic acid pathway.Overexpression of OsJAZ5 facilitated seed germination.The application of OsJAZ5 might be useful for increasing seed germination for rice direct seeding.

Effects of Nitric Oxide on the Germination of Wheat Seeds and Its Reactive Oxygen Species Metabolisms Under Osmotic Stress

Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).

Analysis of Amylase and Superoxide Dismutase Isozymes During the Germination Process of Emmenopterys henryi Oliv Seeds

[ Objective] The study was to understand the changes of amylase（AMY） and superoxide dismutase（SOD） isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.

Effects of Pb Stress on Seed Germination and Seedling Growth of Two Weed Species Seeds

Objective] The aim was to investigate the effects of Pb stress on seed germination and seedling growth of Chenopodium glaucum and Chenopodium serot-inum L. [Method] With C. glaucum and C. serotinum as the study objects, the ef-fects of different concentrations of Pb on their seed germination and seedling growth, as wel as on the leaf SOD, POD and CAT activity were studied primarily. [Result] The germination potential of both the two kinds of weed seeds increased first and then decreased with the increase of Pb concentration. The germination po-tential of C. serotinum and C. glaucum seeds reached the peak at Pb concentration of 25 and 50 mg/L, respectively. With the increase of Pb treatment concentration, the germination rate, germination index and vigor index of C. serotinum and C. glaucum seeds decreased, and their bud length and root length also reduced gradu-al y. ln overal , the leaf SOD, POD and CAT activity of C. glaucum and C. serot-inum_ seedlings increased first and then decreased with the increased treatment concentration of Pb. The leaf SOD and POD activity of C. glaucum and C. serot-inum seedlings reached the maximum at Pb concentration of 200 and 100 mg/L, respectively, and the leaf CAT activity reached the maximum at Pb concentration of 100 mg/L. [Conclusion] The two Chenopodium species had strong tolerance to Pb stress, and they could be used as alternative accumulator plants of soil Pb contami-nation.

Effect of salinity on seed germination, growth and ion content in dimorphic seeds of Salicornia europaea L. （Chenopodiaceae）

The halophyte Salicornia europaea L. is a widely distributed salt-tolerant plant species that produces numerous dimorphic seeds. We studied germination and recovery in dimorphic seeds of Central Asian S. europaea under various salinity conditions. We also tested the effects of various salts on Na＋ and K＋ accumulation during plant development from germination to anthesis under greenhouse conditions. We found good germination （close to control） of large seeds under NaCl between 0.5 and 2%, Na2SO4 and 2NaCl ＋ KCl ＋ CaCl between 0.5 and 3%, and 2Na2SO4 ＋ K2SO4 -- MgSO4 between 0.5 and 5%. For the small seeds, we found stimulating effects of chloride salts （both pure and mixed） under 0.5-1% concentrations, and sulfate salts under 0.5-3%. Both types of seeds showed high germination recovery potential. Salt tolerance limits of the two seed types during germination and at the later stages of development were very similar （4-5%）. During plant growth the optimal concentrations of mixed chloride and sulfate salts ranged from 0.5 to 2%. The mechanisms of salt tolerance in the two seed types of S. europaea appear to differ, but complement each other, improving overall adaptation of this species to high salinity.

Effects of Used Battery on Key Enzyme Activity during the Germination of Wheat Seeds

[Objective] This study aimed to explore the effects of used battery lixivium on wheat germination. [Method] The wheat seeds were treated with used battery lix- ivium at different concentrations to detect the change of activities of amylase, pro- tease, pyruvate dehydrogenase （PDH） and polyphenol oxidase （PPO） during the ger- mination period. [Result] The results showed that the used battery affected enzyme activity. With the increase of concentration of used battery lixivium, trends of the changes of amylase and protease activities were not different. The activities were en- hanced at low concentrations of lixivium, while were inhibited at high concentrations. The tends of changes of pyruvate dehydrogenase （PDH） and polyphenol oxidase （PPO） activities were not consistent with that of either amylase or protease, which showed continuous downward trends with the increasing concentration of used battery lixivium. [Conclusion] This study is of great practical significance for understanding the effects of used battery lixivium on the germination of wheat seeds.

Effects of Cashew Seeds Storage Duration on Germination and Performance of Seedlings in Tanzania

A field trial was set in 2018/2019 season to investigate the capacity of cashew seeds to germinate and its vegetative performance with respect to the storage period at Agricultural Research Institute-(TARI-Naliendele), Mtwara-Tanzania. The variable investigated was the duration of the cashew seeds storage period. Cashew seeds were harvested at polyclonal seed gardens (PSG) for three harvesting seasons 2016, 2017 and 2018 consecutively;seeds were sorted, weighed and soaked before sowing to test viability in respective to storage time. Using a randomized complete block design obeying factorial approach the experiment was laid with three replications. The observed growth parameters were height (cm), number of leaves, leaf length (cm), leaf width (cm), leaf area (sq cm), leaf area index (LAI), canopy diameter (cm) and seedlings canopy ground area (sq cm). The analysis was done by using GenStat under Duncan Multiple Range Test (DMRT) on seed germination. The findings indicated that cashew seeds harvested in 2018 were the superior in both germination and growth vigor differing significantly (p < 0.05) from other seeds harvested in the previous years. Cashew seeds harvested in 2017 were weak and those harvested in 2016 were the worse such that no seeds were able even to germinate. Thus, it is recommendable to sow cashew seeds harvested at the current season for sowing than those stored for more than a year.

Effects of Phosphine on Germination and Physiological Characteristics of Rice Seeds

[Objective] This study aimed to investigate the effects of phosphine on germination and physiological characteristics of rice seeds. [Method] Simulation envi- ronments were conducted to study the effects of high-level phosphine on germination status and physiological characteristics of rice seeds and explore the early environ- mental and ecological effects of phosphine on rice growth in phosphorus cycle of paddy field. [Result] Experimental results showed that the increase of phosphine con- centration in the environment resulted in the decrease of germination rate and ger- mination potential by 11.11% and 19.71%, respectively. In addition, the activities of catalase （CAT） and peroxidase （POD） were reduced to 94.35% and 92.61%, respec- tively; the content of malondialdehyde （MDA） was maximally increased by 29.11%, indicating that both germination potential and growth condition of rice seeds were in- hibited under conditions of high-level phosphine. [Conclusion] This study provided theoretical basis for investigating the effects of phosphine on germination of rice seeds under natural environment.

Influence of Temperature and Salinity on Germination of Eelgrass (Zostera marina L.) Seeds

Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA) (P<0.001). The highest germination rate (83.3 ± 3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃, while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.

The Influence of Induced Drought Stress on Germination of Cenchrus ciliaris L.and Cenchrus setigerus Vahl.:Implications for Rangeland Restoration in the Arid Desert Environment of Kuwait

Drought impacts in arid desert ecosystems can result in decreased ecosystem productivity and biodiversity.Imple­mentation of restoration projects in arid desert environments is largely dependent on water availability and soil mois­ture condition.This study investigated the influence of induced drought stress by using polyethylene glycol(PEG-6000)solution on germination viz.Cenchrus ciliaris and Cenchrus setigerus as the important rangeland species.The water stress potential treatments were 0(control),-0.5 MPa,-1.0 MPa,-1.5 MPa,and-2.0 MPa.The extent of seed germi­nation was severely affected by decreased water stress potential.As drought increased,the percentage of germination decreased in both Cenchrus’species.The water deficit at-0.5 MPa showed a significant(P<0.001)reduction in the final germination percentage in the case of C.setigerus and C.ciliaris by 65%and 42.5%,respectively.At-1.0 MPa to-1.5 MPa,changes in intermediate germination were observed in C.ciliaris(from 35%to 17.5%,respectively)and C.setigerus(from 22.5%to 11.25%respectively).Higher levels of water stress(-2.0 MPa)prevented the survival of both species.Understanding the germination strategies of native desert plant species associated with drought stress and identifying favorable conditions during the germination process can be useful for restoration practices and rangeland management actions to improve desert ecosystems and maintain biodiversity.

Does Cold Plasma Affect Breaking Dormancy and Seed Germination? A Study on Seeds of Lamb's Quarters(Chenopodium album agg.)

Low-pressure discharge is applied for stimulation of germination of two seed lots of Lamb＇s Quarters （Chenopodium album agg.） with different starting germinations （17%, 8%） and in different stages of dormancy. Different exposition durations with cold plasma treatment were applied. The variable of the ratio cumulative germination was calculated. The Richards＇ equation was used for curve-fitting and simulation of the growth curves. Population parameters, namely Vi - viability, Me - time, Qu - dispersion, and Sk - skewness, counted from the curves described the germination rate well. Significant differences among Qu confirmed the erratic dormancy and gradual germination of Lamb＇s Quarters. No difference in the Me parameter was found between two tested seed lots, and no interspecies characteristics were changed using low-pressure discharge. The results suggested that plasma treatment changed seed germination in Lamb＇s Quarters seeds.

Effects of Space Radiation Mutation on Germination and Growth of Sugarcane Hybrid Seeds

[Objectives] This study was conducted to investigate the mutagenic effects of space radiation mutagenesis on sugarcane hybrid seeds. [Methods] Sugarcane hybrid spikes were subjected to space radiation mutagenesis treatment to identify the effects on the germination, seedling growth and plant growth and development of sugarcane hybrid seeds. [Results] The space radiation treatment had a great impact on the germination and growth of sugarcane hybrid seeds, especially on the germination of sugarcane seeds. The germination number per gram of seeds increased significantly, and the survival rate of seedlings increased significantly. The effect on the growth status was relatively small. The average number of tillers decreased slightly, the percentage of available stems increased, and the plants became higher, which resulted in a greater effect on sugarcane yield. Sugarcane sucrose was increased. The seed germination and late growth status indicated that space radiation promoted the germination and growth of sugarcane hybrid seeds. [Conclusions] This study provides a basis for the space radiation mutagenesis breeding of sugarcane hybrid seeds and the promotion of sugarcane breeding process.