[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as...[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as the research objects,the changes in germination potential,germination index,plant height,biomass,and antioxidant enzyme activity of maize seeds were studied under optimal temperature conditions(25℃)and low temperature stress conditions(10℃).[Results]Under 10℃stress,the germination rate and germination index of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4.Under low temperature stress,Taitian 264 exhibited the least reduction in height and biomass,while Zhexuetian 1 had the most reduction.Additionally,the SOD and POD activities of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4 under both temperature conditions,while the MDA content of Taitian 264 was lower.Taitian 264 showed strong germination ability against low temperature stress.[Conclusions]This study provides a basis for timely sowing practices of sweet maize in agricultural production.展开更多
One of the most critical objectives of precision farming is to assess the germination quality of seeds.Modern models contribute to thisfield primarily through the use of artificial intelligence techniques such as machin...One of the most critical objectives of precision farming is to assess the germination quality of seeds.Modern models contribute to thisfield primarily through the use of artificial intelligence techniques such as machine learning,which present difficulties in feature extraction and optimization,which are critical factors in predicting accuracy with few false alarms,and another significant dif-ficulty is assessing germination quality.Additionally,the majority of these contri-butions make use of benchmark classification methods that are either inept or too complex to train with the supplied features.This manuscript addressed these issues by introducing a novel ensemble classification strategy dubbed“Assessing Germination Quality of Seed Samples(AGQSS)by Adaptive Boosting Ensemble Classification”that learns from quantitative phase features as well as universal features in greyscale spectroscopic images.The experimental inquiry illustrates the significance of the proposed model,which outperformed the currently avail-able models when performance analysis was performed.展开更多
Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests ...Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.展开更多
The objective of this work was to determine new approaches that could improve the germination quality of Burkea africana seeds under reproducible conditions and by means available to farmers with a view to its propaga...The objective of this work was to determine new approaches that could improve the germination quality of Burkea africana seeds under reproducible conditions and by means available to farmers with a view to its propagation. The tests concerned the influence of three pre-germinative treatments. It is about the light scarification (Scl), medium scarification (Scm) and deep scarification (Scd) of seeds in order to determine some parameters of germination that are the latency time, the time of germination, the rate of germination and the speed of germination. The treated seeds were sown in transparent germinators lined with hydrophilic paper and then after the appearance of radicles, the plants were transplanted on five types of substrates (black soil, fine sand, sawdust, mixtures 1/1 of sawdust-black soil and 1/1 of sawdust-fine sand). The results obtained by the deep (Scp) and medium (Scm) scarification compared to those of the light scarification and the control, showed a clear reduction of the lag time (3 days/15 days (control). At the 5% threshold, germination times 6.27 × 10<sup>-1</sup> (Scd) and 6.01 × 10<sup>-1</sup> (Scm) were significantly influenced. Germination rates 4.18 × 10<sup>-1</sup> (Scd) and 3.92 × 10<sup>-1</sup> (Scm) are also influenced by the pretreatment. Germination rates are significantly improved (80%). Regardless of the under treatment, the substrate “sawdust and fine sand” improves the germination of scarified seeds by 14.07% more compared to the substrate “fine sand” at the 5% threshold. The mechanical scarification and the type of substrates thus influence positively and homogeneously the germination of seeds of Burkea africana. The domestication of this species is thus possible and can be considered for useful purposes.展开更多
Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the cond...Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the conditions of introduction of the Tashkent Botanical Garden of Uzbekistan. Thus, the optimal temperature for germination of L. tatarica seeds in laboratory conditions is +20°C + 22°C, at which germination was 73%. The germination rate of seeds sown in autumn in the field was 62%, and the germination rate of seeds sown in spring was 71%. It was noted that in greenhouse conditions at an air temperature of 20°C - 22°C and a relative humidity of 49% - 53%, the rootability of cuttings was 75%. It was revealed that the studied species adapted well to the conditions of introduction. Taking into account the effectiveness of vegetative reproduction of L. tatarica, it can be recommended for improving the aesthetic condition and landscaping of cities, landscaping and landscape design.展开更多
As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different...As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.展开更多
Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination u...Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination under drought conditions is still poorly understood.Therefore,we studied the effects of melatonin on rice seed germination and physiological characteristics under drought stress.Rice seeds were treated with different concentrations of melatonin(i.e.,0,20,100,and 500μM)and drought stress was simulated with 5%polyethylene glycol 6000(PEG6000).The results showed that 100μM melatonin can effectively improve the germination potential,rate and index;the vigor index of rice seeds;and the length of the shoot and root.In addition,that treatment also increased the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),and reduced the content of malondialdehyde(MDA).The grey relational grade between the shoot MDA content and the melatonin seed-soaking treatment was the highest,which could be useful for evaluating the effect of melatonin on drought tolerance.Two-way analysis of variance showed that the effect of single melatonin treatment on rice seeds was more significant than that of single drought stress and interaction treatment of drought and melatonin(p<0.05).The subordinate function results showed that 100μM melatonin significantly improved the germination and physiological indexes of rice seeds and effectively alleviated the adverse effects of drought stress on rice seedlings.The results helped to improve the understanding of the morphological and physiological involvement of melatonin in promoting seed germination and seedling development under drought stress.展开更多
On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60...On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)were analyzed.The results showed that maize germination rate,germination vigor and growth index decreased with the increase of Pb concentration.The root length,surface area of maize increased by 0.21%-81.58%,8.99%-73.43%,1.50%-77.37%,respectively,under 20-500 mg/L Pb concentration.However,these parameters under 1000-3000 mg/L Pb concentration decreased by 37.86%-553.54%,44.99%-766.16%,55.99%-92.81%,respectively,and these lowest value appeared in 3000 mg/L Pb treatment.The root volume of maize increased by 4.57%-89.25%in 20-80 mg/L Pb concentration,and it decreased with the increase of Pb concentration when the Pb concentration was higher than 80 mg/L and decreased by 94.13%in 3000 mg/L Pb.The root surface area and length of 0.50-1.00 diameter class were higher than those of other diameter classes,and these value of maize under 500 mg/L Pb were higher than those of other concentrations.The length and perimeter of maize leaves with the highest value of 220.36 and 962.68 mm,respectively appeared in 60 mg/L Pb treatment.The leaf width and area of maize with the highest value of 15.68 mm and 2448.31 mm^(2),respectively,appeared in 40 mg/L Pb treatment,which indicated that the leaf traits of maize were promoted by low concentration Pb and inhibited by high concentration Pb.展开更多
Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarp...Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.展开更多
Micronutrient nanoparticles(NPs)are currently an option for chemical fertilization and biostimulation in crops.However,there is little information on the phytotoxic or biostimulatory effects of NPs at low concentratio...Micronutrient nanoparticles(NPs)are currently an option for chemical fertilization and biostimulation in crops.However,there is little information on the phytotoxic or biostimulatory effects of NPs at low concentrations of some elements,such as Zn.In this study,the effect of low concentrations of Zn oxide(ZnO)NPs on germination,growth variables,and nutritional attributes of lettuce(Lactuca sativa L.)was evaluated in comparison to Zn sulfate.Romaine lettuce seeds were treated with ZnSO_(4)^(-)×7H_(2)O and ZnO NPs at Zn molar concentrations of 1×10^(−3),5×10^(−3),1×10^(−4),5×10^(−4),1×10^(−5),5×10^(−5),1×10^(−6),and 5×10^(−6).The seeds treated with ZnSO4−at 5×10^(−6)registered the highest radicle length,73%more than the control treatment.The seeds treated with ZnSO4−at 5×10^(−3)registered the lowest values,with 50%less than the control treatment.ZnO NPs at 5×10^(−6)significantly increased content of chlorophyll A and B and total phenolics.These results indicate the possible existence of a mechanism related to the intrinsic nanoparticle properties,especially at low concentrations.展开更多
Ilex asprella(Hook.et Arn.)Champ.ex Benth is one of the most important traditional Chinese medicines in southern China.The seeds of Ilex asprella usually have extremely low germination due to their dormancy characteri...Ilex asprella(Hook.et Arn.)Champ.ex Benth is one of the most important traditional Chinese medicines in southern China.The seeds of Ilex asprella usually have extremely low germination due to their dormancy characteristics,which severely impacts the efficiency of seedling raising and increases labor costs.In this study,to improve the seed germination of I.asprella,the effects of germination substrate,hormone,winnowing,and stratification treatments on the seed germination of I.asprella were investigated.The results of the germination matrix showed that the highest germination percentage of 45.2%was achieved under the 20℃/10℃day/night temperature and vermiculite germination medium conditions.The results of hormone treatments revealed that 100–400 mg/L of gibberellin(GA)and 50–100 mg/L of salicylic acid(SA)were found to be effective in releasing the dormancy of I.asprella seeds.Moreover,winnowing could effectively eliminate unsaturated seeds and impurities,thus improving the seed germination of I.asprella.Furthermore,warm temperature(15℃)stratification could expand the temperature range of I.asprella’s seed germination,which was beneficial for seed germination of I.asprella and for seed nursery at room temperature in production practice.The present study obtained a method to break dormancy and increase seed germination in I.asprella,thereby forming a groundwork for improving the efficiency of large-scale planting of I.asprella.展开更多
Alfalfa(Medicago sativa L.),when exposed to abiotic stress such as salinity,suffers significant losses in yield and productivity.The present study evaluated the salinity tolerance of 12 alfalfa cultivars in vitro usin...Alfalfa(Medicago sativa L.),when exposed to abiotic stress such as salinity,suffers significant losses in yield and productivity.The present study evaluated the salinity tolerance of 12 alfalfa cultivars in vitro using five concentrations of sodium chloride(NaCl),ranging from 0 to 250 mmol L^(−1).The results obtained in the current study revealed that the Saudi cultivars,Kasimi and Hassawi,and the German cultivar(Berlin)had the highest salinity tolerance in terms of germination percentage(GP),corrected germination rate index(CGRI),days to reach 50%germination(GT_(50)),and ability to form cotyledonary and true leaves.Under mmol L^(−1) NaCl,the Saudi cultivar Kasimi cultivar showed GP,CGRI,and GT_(50) of 55.20%,123.15,and 3.77 days,respectively.Similarly,the German cultivar(Berlin)showed GP,CGRI,and GT_(50) of 50.06%,86.61,and 5.17 days,respectively.These findings might reveal a pivotal aspect in salt tolerance in alfalfa.Our results will help to select salt-tolerant alfalfa cultivars that could thrive in arid and semi-arid areas with salinity problems.展开更多
Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) for 5 minutes,...Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) 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.展开更多
[Objectives]In this experiment,wheat seeds were treated with different concentrations of gibberellin and different concentrations of salt solution to study the change of germination index of wheat seeds.[Methods]The g...[Objectives]In this experiment,wheat seeds were treated with different concentrations of gibberellin and different concentrations of salt solution to study the change of germination index of wheat seeds.[Methods]The germination rate,germination potential and germination index of wheat seeds were measured by routine methods,and the effect of exogenous gibberellin on germination of wheat seeds under salt stress was observed.[Results]The germination rate,germination potential and germination index of wheat seeds under salt stress were significantly increased after exogenous treatment of 0.25 and 0.50 g/L gibberellin within the range of salt concentration gradient.However,when the concentration of gibberellin was too high,it would inhibit the germination of seeds.[Conclusions]Appropriate concentration of gibberellin can effectively alleviate the stress caused by salt on wheat seed germination.In this experiment,the best concentration of gibberellin to alleviate salt stress was 0.25 g/L.展开更多
[Objectives]To explore the conditions for in vitro culture of Yangmei pollen.[Methods]Experiments were conducted on the germination characteristics of three types of Yangmei pollen using in vitro culture and germinati...[Objectives]To explore the conditions for in vitro culture of Yangmei pollen.[Methods]Experiments were conducted on the germination characteristics of three types of Yangmei pollen using in vitro culture and germination method.[Results]The suitable medium ratio for the germination of Yangmei pollen was 10%sucrose+0.01%borax+1%agar;the cultivation temperature of 30℃was more suitable for the germination of Yangmei pollen than 25℃;through analysis of variance,among the three types of Yangmei pollen,pollen of male 1 had the strongest viability,and it was the better pollination type.[Conclusions]The research could provide certain basis for introduction and cultivation of Yangmei and improving hybrid breeding effect.展开更多
Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during pla...Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during planting.In this study,transcriptomic profiles of low-temperature-and normal-temperature-germinated seeds of Xinluzao 25,a variety with low-temperature tolerance and high germination rates,were analyzed and compared.The following results were obtained.(1)A total of 81.06 Gb of clean data were obtained after transcriptome sequencing and assembly,and 76,931 non-redundant Unigene sequences were obtained after data consolidation and concatenation;of these,69,883 Unigene sequences were annotated.In addition,55,463 Unigene transcript sequences(72.2%)were annotated for Gene Ontology(GO)classification,and 26,629 genes were involved in 50 metabolic pathways identified by Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.(2)Three main pathways related to low-temperature tolerance of seed germination were identified:starch and sucrose metabolism,phenylpropanoid biosynthesis,and cysteine and methionine metabolism.Their main molecular functions involve the regulation of abscisic acid and activities of enzymes such as amylase,peroxidase,and oxidoreductase.During germination at low temperature,more genes were down-regulated than up-regulated genes at the protrusion stage(2 mm),and more genes were up-regulated than down-regulated at the germination stage(30 mm)after protrusion.(3)The enzyme activities at the two stages showed that amylase,peroxidase,catalase,and glutathione reductase had higher activities when the seeds germinated at 15℃.In this study,high expression of amylase,peroxidase,catalase,and glutathione reductase genes may be the main cause of increased tolerance to low temperature.展开更多
The demand for medicinal plants at the origin of phyto-drugs,like all ethnobotanical plants,threatens their existence today.The aim of this work was to determine suitable methods for optimizing the possibilities of re...The demand for medicinal plants at the origin of phyto-drugs,like all ethnobotanical plants,threatens their existence today.The aim of this work was to determine suitable methods for optimizing the possibilities of regenerating Stereospermum kunthianum.To achieve this objective,3 levels of mechanical scarification(light scarification,medium scarification and deep scarification)were applied to the seeds of this species using a rough instrument,and 5 days after germination,the seedlings were transplanted into 5 types of substrate to study their effects on seedling growth.The length of the seedlings was measured using a graduated ruler.The results obtained showed that the best latency time was 2 days for average seed scarifications.The highest germination half-time was 4.00±0.06 days observed for average seed scarification,the highest germination speed was 22.50±1.00 and the highest germination rate was 100.00%±0.00%for average scarification.The homogeneous substrate mixes black earth/woodsilk and Fine sand/woodsilk were more effective for seedling growth(1.9 cm/day in the juvenile state)and development.Medium seed scarification is the most effective method for regenerating Stereospermum kunthianum,and the black earth/wood shavings substrate mix is the best for its cultivation.展开更多
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 availabi...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.展开更多
Low germination and vigor of rice seed associated with dry-seed broadcasting are common problems encountered by rice growers.The objectives of this study were to evaluate the role of potassium nitrate(KNO3)on the pa...Low germination and vigor of rice seed associated with dry-seed broadcasting are common problems encountered by rice growers.The objectives of this study were to evaluate the role of potassium nitrate(KNO3)on the pattern of seed imbibition and to determine the effect of seed priming with KNO3 on the germination percentage,speed and uniformity of germination in rice seed.Experiment 1 compared the patterns of seed imbibition of six concentrations of KNO3(0,0.25,0.50,1.00,1.50,and 2.00%)in two rice cultivars-KDML105 and RD15.The results showed that soaking rice seed in KNO3 at higher concentrations could delay the imbibition time.The higher concentrations of KNO3 delayed the imbibition time of rice seed and took a longer time to reach the end of phases 1 and 2 compared to the lower concentrations.The patterns of seed imbibition using distilled water of both rice cultivars(KDML105 and RD15)were quite similar,but with different concentrations of KNO3,the imbibition time taken to reach the end of phases 1 and 2 was slightly postponed in KDML105 suggesting that different rice cultivars may need different imbibition times for soaking seed in the priming process.Experiment 2 evaluated the effects of seed priming with 1.0 and 2.0%KNO3 at different imbibition times.It was found that priming with 1.0%KNO3 showed better seed germination than priming with 2.0%KNO3 and seed priming with 1.0%KNO3 at the imbibition time of early phase 2(or 28 h for KDML105)improved seed germination and increased both the speed and uniformity of seed germination.The results of this study show promise for the use of priming with 1.0%KNO3 soaked until early phase 2 of seed imbibition for improving the seed germination and vigor of rice in dry seed broadcasting.展开更多
The effects of arsenic (As) were investigated on seed germination, root and shoot length and their biomass and some other factors to elucidate the toxicity of As. The results showed low concentrations of As (0-1 mg...The effects of arsenic (As) were investigated on seed germination, root and shoot length and their biomass and some other factors to elucidate the toxicity of As. The results showed low concentrations of As (0-1 mg/kg) stimulated seed germination and the growth of root and shoot, however, these factors all decreased gradually at high concentrations of As (5-20 mg/kg). The contents of O2^-, MDA, soluble protein and peroxidase (POD) activity all increased with increasing As concentrations. Soluble sugar content, ascorbate peroxidase (APX), and superoxide dismutase (SOD) activities decreased at low concentrations of As, and increased at high concentrations of As. While acetylsalicylic acid (ASA) and chlorophyll contents, catalase (CAT) activity displayed increasing trend when the concentrations of As was lower than 1 mg/kg, and then decreasing trend. By polyacrylamide gel electrophoresis (PAGE), As induced the expression of POD isozymes of wheat seedlings. As induced the expression of CAT isozymes but inhibited the expression of SOD isozymes of wheat seedlings at concentrations lower than 1 mg/kg. However, As inhibited the expression of CAT isozymes but induced the expression of SOD isozymes at concentrations higher than 5 mg/kg. The results indicated As could exert harmfulness in the early development stage of wheat at inappropriate concentrations.展开更多
基金Supported by Zhejiang Basic Public Welfare Research Program Project(LGN21C020006)Key Research and Development Project of Zhejiang Province(2021C02057)+1 种基金Zhejiang Major Science and Technology Project of Agricultural New Variety(Upland Food)Breeding(2021C02064)Key Research and Development Project of Zhejiang Province(2022C04024).
文摘[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as the research objects,the changes in germination potential,germination index,plant height,biomass,and antioxidant enzyme activity of maize seeds were studied under optimal temperature conditions(25℃)and low temperature stress conditions(10℃).[Results]Under 10℃stress,the germination rate and germination index of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4.Under low temperature stress,Taitian 264 exhibited the least reduction in height and biomass,while Zhexuetian 1 had the most reduction.Additionally,the SOD and POD activities of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4 under both temperature conditions,while the MDA content of Taitian 264 was lower.Taitian 264 showed strong germination ability against low temperature stress.[Conclusions]This study provides a basis for timely sowing practices of sweet maize in agricultural production.
文摘One of the most critical objectives of precision farming is to assess the germination quality of seeds.Modern models contribute to thisfield primarily through the use of artificial intelligence techniques such as machine learning,which present difficulties in feature extraction and optimization,which are critical factors in predicting accuracy with few false alarms,and another significant dif-ficulty is assessing germination quality.Additionally,the majority of these contri-butions make use of benchmark classification methods that are either inept or too complex to train with the supplied features.This manuscript addressed these issues by introducing a novel ensemble classification strategy dubbed“Assessing Germination Quality of Seed Samples(AGQSS)by Adaptive Boosting Ensemble Classification”that learns from quantitative phase features as well as universal features in greyscale spectroscopic images.The experimental inquiry illustrates the significance of the proposed model,which outperformed the currently avail-able models when performance analysis was performed.
基金the National Natural Science Foundation of China(No.31901300)Natural Science Foundation of Guizhou Province+2 种基金China(No.(2019)1165)Science and Technology Foundation of Guizhou ProvinceChina(No.[2018]137,No.[2018]133)。
文摘Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.
文摘The objective of this work was to determine new approaches that could improve the germination quality of Burkea africana seeds under reproducible conditions and by means available to farmers with a view to its propagation. The tests concerned the influence of three pre-germinative treatments. It is about the light scarification (Scl), medium scarification (Scm) and deep scarification (Scd) of seeds in order to determine some parameters of germination that are the latency time, the time of germination, the rate of germination and the speed of germination. The treated seeds were sown in transparent germinators lined with hydrophilic paper and then after the appearance of radicles, the plants were transplanted on five types of substrates (black soil, fine sand, sawdust, mixtures 1/1 of sawdust-black soil and 1/1 of sawdust-fine sand). The results obtained by the deep (Scp) and medium (Scm) scarification compared to those of the light scarification and the control, showed a clear reduction of the lag time (3 days/15 days (control). At the 5% threshold, germination times 6.27 × 10<sup>-1</sup> (Scd) and 6.01 × 10<sup>-1</sup> (Scm) were significantly influenced. Germination rates 4.18 × 10<sup>-1</sup> (Scd) and 3.92 × 10<sup>-1</sup> (Scm) are also influenced by the pretreatment. Germination rates are significantly improved (80%). Regardless of the under treatment, the substrate “sawdust and fine sand” improves the germination of scarified seeds by 14.07% more compared to the substrate “fine sand” at the 5% threshold. The mechanical scarification and the type of substrates thus influence positively and homogeneously the germination of seeds of Burkea africana. The domestication of this species is thus possible and can be considered for useful purposes.
文摘Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the conditions of introduction of the Tashkent Botanical Garden of Uzbekistan. Thus, the optimal temperature for germination of L. tatarica seeds in laboratory conditions is +20°C + 22°C, at which germination was 73%. The germination rate of seeds sown in autumn in the field was 62%, and the germination rate of seeds sown in spring was 71%. It was noted that in greenhouse conditions at an air temperature of 20°C - 22°C and a relative humidity of 49% - 53%, the rootability of cuttings was 75%. It was revealed that the studied species adapted well to the conditions of introduction. Taking into account the effectiveness of vegetative reproduction of L. tatarica, it can be recommended for improving the aesthetic condition and landscaping of cities, landscaping and landscape design.
基金supported by the Gorgan University of Agricultural Sciences and Natural ResourcesSabz Fanavaran Loozan Shomal Company+1 种基金University of GuilanGuilan Science and Technology Park, Iran
文摘As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.
基金This work was funded by the National Natural Science Foundation of China(31971923,31301650)the National Key R&D Program of China(2017YFD0301501)+2 种基金the Hunan Provincial Natural Science Foundation of China(2020JJ4360)the Key Scientific Research Project of Hunan Provincial Education Department of China(19A220)Innovation and Entrepreneurship Training Program for College Students of Hunan Agricultural University(XCX2021038).
文摘Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination under drought conditions is still poorly understood.Therefore,we studied the effects of melatonin on rice seed germination and physiological characteristics under drought stress.Rice seeds were treated with different concentrations of melatonin(i.e.,0,20,100,and 500μM)and drought stress was simulated with 5%polyethylene glycol 6000(PEG6000).The results showed that 100μM melatonin can effectively improve the germination potential,rate and index;the vigor index of rice seeds;and the length of the shoot and root.In addition,that treatment also increased the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),and reduced the content of malondialdehyde(MDA).The grey relational grade between the shoot MDA content and the melatonin seed-soaking treatment was the highest,which could be useful for evaluating the effect of melatonin on drought tolerance.Two-way analysis of variance showed that the effect of single melatonin treatment on rice seeds was more significant than that of single drought stress and interaction treatment of drought and melatonin(p<0.05).The subordinate function results showed that 100μM melatonin significantly improved the germination and physiological indexes of rice seeds and effectively alleviated the adverse effects of drought stress on rice seedlings.The results helped to improve the understanding of the morphological and physiological involvement of melatonin in promoting seed germination and seedling development under drought stress.
基金Basic Research in Yunnan Local Colleges and Universities(2017FH001-026,2018FH001-004)the National Natural Science Foundation of China(42167009,31300349)International Joint Innovation Team for Yunnan Plateau Lakes and Great Lakes of North America which is sponsored by Yunnan Provincial Education Department(to XC),and Scientific and Technological Innovation team Project of Agricultural Resources Utilization of Kunming University.
文摘On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)were analyzed.The results showed that maize germination rate,germination vigor and growth index decreased with the increase of Pb concentration.The root length,surface area of maize increased by 0.21%-81.58%,8.99%-73.43%,1.50%-77.37%,respectively,under 20-500 mg/L Pb concentration.However,these parameters under 1000-3000 mg/L Pb concentration decreased by 37.86%-553.54%,44.99%-766.16%,55.99%-92.81%,respectively,and these lowest value appeared in 3000 mg/L Pb treatment.The root volume of maize increased by 4.57%-89.25%in 20-80 mg/L Pb concentration,and it decreased with the increase of Pb concentration when the Pb concentration was higher than 80 mg/L and decreased by 94.13%in 3000 mg/L Pb.The root surface area and length of 0.50-1.00 diameter class were higher than those of other diameter classes,and these value of maize under 500 mg/L Pb were higher than those of other concentrations.The length and perimeter of maize leaves with the highest value of 220.36 and 962.68 mm,respectively appeared in 60 mg/L Pb treatment.The leaf width and area of maize with the highest value of 15.68 mm and 2448.31 mm^(2),respectively,appeared in 40 mg/L Pb treatment,which indicated that the leaf traits of maize were promoted by low concentration Pb and inhibited by high concentration Pb.
基金Supported by the National Key R&D Program of China(No.2018YFD0901502)the Ningbo Key R&D Science and Technology Program(Nos.2019B10009,2021Z114)the Natural Science Foundation of Zhejiang Province(Nos.LY19C190003,LQ20C190002)。
文摘Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.
文摘Micronutrient nanoparticles(NPs)are currently an option for chemical fertilization and biostimulation in crops.However,there is little information on the phytotoxic or biostimulatory effects of NPs at low concentrations of some elements,such as Zn.In this study,the effect of low concentrations of Zn oxide(ZnO)NPs on germination,growth variables,and nutritional attributes of lettuce(Lactuca sativa L.)was evaluated in comparison to Zn sulfate.Romaine lettuce seeds were treated with ZnSO_(4)^(-)×7H_(2)O and ZnO NPs at Zn molar concentrations of 1×10^(−3),5×10^(−3),1×10^(−4),5×10^(−4),1×10^(−5),5×10^(−5),1×10^(−6),and 5×10^(−6).The seeds treated with ZnSO4−at 5×10^(−6)registered the highest radicle length,73%more than the control treatment.The seeds treated with ZnSO4−at 5×10^(−3)registered the lowest values,with 50%less than the control treatment.ZnO NPs at 5×10^(−6)significantly increased content of chlorophyll A and B and total phenolics.These results indicate the possible existence of a mechanism related to the intrinsic nanoparticle properties,especially at low concentrations.
基金supported by the Fund Projects of the Central Government in Guidance of Local Science and Technology Development(GuiKeZY22096020)Natural Science Foundation of Guangxi(2019GXNSFBA245073)+1 种基金National Natural Science Foundation of China(82260750,82260749)Cooperative Project of Guangxi Botanical Garden of Medicinal Plants with China Resources Sanjiu Medical&Pharmaceutical Co.,Ltd.(202112-1).
文摘Ilex asprella(Hook.et Arn.)Champ.ex Benth is one of the most important traditional Chinese medicines in southern China.The seeds of Ilex asprella usually have extremely low germination due to their dormancy characteristics,which severely impacts the efficiency of seedling raising and increases labor costs.In this study,to improve the seed germination of I.asprella,the effects of germination substrate,hormone,winnowing,and stratification treatments on the seed germination of I.asprella were investigated.The results of the germination matrix showed that the highest germination percentage of 45.2%was achieved under the 20℃/10℃day/night temperature and vermiculite germination medium conditions.The results of hormone treatments revealed that 100–400 mg/L of gibberellin(GA)and 50–100 mg/L of salicylic acid(SA)were found to be effective in releasing the dormancy of I.asprella seeds.Moreover,winnowing could effectively eliminate unsaturated seeds and impurities,thus improving the seed germination of I.asprella.Furthermore,warm temperature(15℃)stratification could expand the temperature range of I.asprella’s seed germination,which was beneficial for seed germination of I.asprella and for seed nursery at room temperature in production practice.The present study obtained a method to break dormancy and increase seed germination in I.asprella,thereby forming a groundwork for improving the efficiency of large-scale planting of I.asprella.
基金funded by the Researchers Supporting Project No.(RSP-2021/390),King Saud University,Riyadh,Saudi Arabia.
文摘Alfalfa(Medicago sativa L.),when exposed to abiotic stress such as salinity,suffers significant losses in yield and productivity.The present study evaluated the salinity tolerance of 12 alfalfa cultivars in vitro using five concentrations of sodium chloride(NaCl),ranging from 0 to 250 mmol L^(−1).The results obtained in the current study revealed that the Saudi cultivars,Kasimi and Hassawi,and the German cultivar(Berlin)had the highest salinity tolerance in terms of germination percentage(GP),corrected germination rate index(CGRI),days to reach 50%germination(GT_(50)),and ability to form cotyledonary and true leaves.Under mmol L^(−1) NaCl,the Saudi cultivar Kasimi cultivar showed GP,CGRI,and GT_(50) of 55.20%,123.15,and 3.77 days,respectively.Similarly,the German cultivar(Berlin)showed GP,CGRI,and GT_(50) of 50.06%,86.61,and 5.17 days,respectively.These findings might reveal a pivotal aspect in salt tolerance in alfalfa.Our results will help to select salt-tolerant alfalfa cultivars that could thrive in arid and semi-arid areas with salinity problems.
文摘Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) 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.
基金Supported by School-level Training Program of Hetian Vocational Technical College(HZ-2022-10).
文摘[Objectives]In this experiment,wheat seeds were treated with different concentrations of gibberellin and different concentrations of salt solution to study the change of germination index of wheat seeds.[Methods]The germination rate,germination potential and germination index of wheat seeds were measured by routine methods,and the effect of exogenous gibberellin on germination of wheat seeds under salt stress was observed.[Results]The germination rate,germination potential and germination index of wheat seeds under salt stress were significantly increased after exogenous treatment of 0.25 and 0.50 g/L gibberellin within the range of salt concentration gradient.However,when the concentration of gibberellin was too high,it would inhibit the germination of seeds.[Conclusions]Appropriate concentration of gibberellin can effectively alleviate the stress caused by salt on wheat seed germination.In this experiment,the best concentration of gibberellin to alleviate salt stress was 0.25 g/L.
文摘[Objectives]To explore the conditions for in vitro culture of Yangmei pollen.[Methods]Experiments were conducted on the germination characteristics of three types of Yangmei pollen using in vitro culture and germination method.[Results]The suitable medium ratio for the germination of Yangmei pollen was 10%sucrose+0.01%borax+1%agar;the cultivation temperature of 30℃was more suitable for the germination of Yangmei pollen than 25℃;through analysis of variance,among the three types of Yangmei pollen,pollen of male 1 had the strongest viability,and it was the better pollination type.[Conclusions]The research could provide certain basis for introduction and cultivation of Yangmei and improving hybrid breeding effect.
基金funded by the Science and Technology Project of Henan Provincial Department of Science and Technology(Item No.222102110282).
文摘Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during planting.In this study,transcriptomic profiles of low-temperature-and normal-temperature-germinated seeds of Xinluzao 25,a variety with low-temperature tolerance and high germination rates,were analyzed and compared.The following results were obtained.(1)A total of 81.06 Gb of clean data were obtained after transcriptome sequencing and assembly,and 76,931 non-redundant Unigene sequences were obtained after data consolidation and concatenation;of these,69,883 Unigene sequences were annotated.In addition,55,463 Unigene transcript sequences(72.2%)were annotated for Gene Ontology(GO)classification,and 26,629 genes were involved in 50 metabolic pathways identified by Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.(2)Three main pathways related to low-temperature tolerance of seed germination were identified:starch and sucrose metabolism,phenylpropanoid biosynthesis,and cysteine and methionine metabolism.Their main molecular functions involve the regulation of abscisic acid and activities of enzymes such as amylase,peroxidase,and oxidoreductase.During germination at low temperature,more genes were down-regulated than up-regulated genes at the protrusion stage(2 mm),and more genes were up-regulated than down-regulated at the germination stage(30 mm)after protrusion.(3)The enzyme activities at the two stages showed that amylase,peroxidase,catalase,and glutathione reductase had higher activities when the seeds germinated at 15℃.In this study,high expression of amylase,peroxidase,catalase,and glutathione reductase genes may be the main cause of increased tolerance to low temperature.
文摘The demand for medicinal plants at the origin of phyto-drugs,like all ethnobotanical plants,threatens their existence today.The aim of this work was to determine suitable methods for optimizing the possibilities of regenerating Stereospermum kunthianum.To achieve this objective,3 levels of mechanical scarification(light scarification,medium scarification and deep scarification)were applied to the seeds of this species using a rough instrument,and 5 days after germination,the seedlings were transplanted into 5 types of substrate to study their effects on seedling growth.The length of the seedlings was measured using a graduated ruler.The results obtained showed that the best latency time was 2 days for average seed scarifications.The highest germination half-time was 4.00±0.06 days observed for average seed scarification,the highest germination speed was 22.50±1.00 and the highest germination rate was 100.00%±0.00%for average scarification.The homogeneous substrate mixes black earth/woodsilk and Fine sand/woodsilk were more effective for seedling growth(1.9 cm/day in the juvenile state)and development.Medium seed scarification is the most effective method for regenerating Stereospermum kunthianum,and the black earth/wood shavings substrate mix is the best for its cultivation.
基金This study was made possible by generous support of the Kuwait Institute for Scientific Research(KISR).
文摘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.
基金financially supported by a Kasetsart University 72 Year Anniversary Graduate Scholarship, from the Graduate School, Kasetsart University, Thailand
文摘Low germination and vigor of rice seed associated with dry-seed broadcasting are common problems encountered by rice growers.The objectives of this study were to evaluate the role of potassium nitrate(KNO3)on the pattern of seed imbibition and to determine the effect of seed priming with KNO3 on the germination percentage,speed and uniformity of germination in rice seed.Experiment 1 compared the patterns of seed imbibition of six concentrations of KNO3(0,0.25,0.50,1.00,1.50,and 2.00%)in two rice cultivars-KDML105 and RD15.The results showed that soaking rice seed in KNO3 at higher concentrations could delay the imbibition time.The higher concentrations of KNO3 delayed the imbibition time of rice seed and took a longer time to reach the end of phases 1 and 2 compared to the lower concentrations.The patterns of seed imbibition using distilled water of both rice cultivars(KDML105 and RD15)were quite similar,but with different concentrations of KNO3,the imbibition time taken to reach the end of phases 1 and 2 was slightly postponed in KDML105 suggesting that different rice cultivars may need different imbibition times for soaking seed in the priming process.Experiment 2 evaluated the effects of seed priming with 1.0 and 2.0%KNO3 at different imbibition times.It was found that priming with 1.0%KNO3 showed better seed germination than priming with 2.0%KNO3 and seed priming with 1.0%KNO3 at the imbibition time of early phase 2(or 28 h for KDML105)improved seed germination and increased both the speed and uniformity of seed germination.The results of this study show promise for the use of priming with 1.0%KNO3 soaked until early phase 2 of seed imbibition for improving the seed germination and vigor of rice in dry seed broadcasting.
基金Project supported by the National"Eleventh Five-Year Plan"Impor-tant Special Program of China(No.2006BAD02A15)the NaturalScience Foundation of Henan Province(No.0411031800)the Application Science and Technology Study Foundation of Henan Normal University(No.2004Y02).
文摘The effects of arsenic (As) were investigated on seed germination, root and shoot length and their biomass and some other factors to elucidate the toxicity of As. The results showed low concentrations of As (0-1 mg/kg) stimulated seed germination and the growth of root and shoot, however, these factors all decreased gradually at high concentrations of As (5-20 mg/kg). The contents of O2^-, MDA, soluble protein and peroxidase (POD) activity all increased with increasing As concentrations. Soluble sugar content, ascorbate peroxidase (APX), and superoxide dismutase (SOD) activities decreased at low concentrations of As, and increased at high concentrations of As. While acetylsalicylic acid (ASA) and chlorophyll contents, catalase (CAT) activity displayed increasing trend when the concentrations of As was lower than 1 mg/kg, and then decreasing trend. By polyacrylamide gel electrophoresis (PAGE), As induced the expression of POD isozymes of wheat seedlings. As induced the expression of CAT isozymes but inhibited the expression of SOD isozymes of wheat seedlings at concentrations lower than 1 mg/kg. However, As inhibited the expression of CAT isozymes but induced the expression of SOD isozymes at concentrations higher than 5 mg/kg. The results indicated As could exert harmfulness in the early development stage of wheat at inappropriate concentrations.