Understanding the distribution,dispersal,and correlation of modern pollen with vegetation in mountainous regions is essential for establishing accurate modern analogs for fossil pollen records.This study,conducted in ...Understanding the distribution,dispersal,and correlation of modern pollen with vegetation in mountainous regions is essential for establishing accurate modern analogs for fossil pollen records.This study,conducted in Leigong Mountain on the YunnanGuizhou Plateau of southwestern China,involved the collection of 35 surface soil samples from diverse vegetation communities along an elevational gradient ranging from 1210 to 1875 meters.The results reveal a close correspondence between modern pollen assemblages and vegetation zones.Principal Component Analysis(PCA)results indicate that pollen assemblages can effectively distinguish between subtropical montane evergreen broad-leaved forest(SEBF)and subtropical montane deciduous broadleaved forest(SDBF).However,both SEBF and SDBF show significant overlap with subtropical montane evergreen-deciduous broad-leaved mixed forest(SEMF).Detrended Correspondence Analysis(DCA)results clearly distinguish the three vegetation zones,and the first axis of DCA shows a significant positive correlation with elevation(p<0.01,R=0.48).Discriminant Analysis(DA)successfully assigns 94.4%of the modern pollen samples to their respective vegetation zones.Pollen taxa such as Impatiens,Astertype,and Rosaceae exhibit significant indicative capabilities for the SEBF zone,effectively distinguishing this vegetation zone from others.Pinus and Alnus display overrepresentation in the Leigong Mountain region,while Quercus(D,deciduous-type)and Poaceae exhibit high representation in the SEBF zone.In the SEBF zone,both pollen diversity and richness are the lowest.Our study reveals the complex relationship between the richness and diversity of pollen and vegetation.The diversity and richness of tree and shrub pollen are found to be lower than those of the corresponding plants.The pollen-vegetation relationship elucidated in this study serves as a critical reference for reconstructing ancient environments from fossil pollen retrieved in this region.展开更多
Watermelon(Citrullus lanatus)holds global significance as a fruit with high economic and nutritional value.Exploring the regulatory network of watermelon male reproductive development is crucial for developing male st...Watermelon(Citrullus lanatus)holds global significance as a fruit with high economic and nutritional value.Exploring the regulatory network of watermelon male reproductive development is crucial for developing male sterile materials and facilitating cross-breeding.Despite its importance,there is a lack of research on the regulation mechanism of male reproductive development in watermelon.In this study,we identified that ClESR2,a VIIIb subclass member in the APETALA2/Ethylene Responsive Factor(AP2/ERF)superfamily,was a key factor in pollen development.RNA insitu hybridization confirmed significantClESR2 expression in the tapetum and pollen during the later stage of anther development.The pollens of transgenic plants showed major defects in morphology and vitality at the late development stage.The RNA-seq and protein interaction assay confirmed that ClESR2 regulates pollen morphology and fertility by interacting with key genes involved in pollen development at both transcriptional and protein levels.These suggest that Enhancer of Shoot Regeneration 2(ESR2)plays an important role in pollen maturation and vitality.This study helps understand the male reproductive development of watermelon,providing a theoretical foundation for developing male sterile materials.展开更多
Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce th...Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.展开更多
Lily(Lilium spp.)is an important horticultural crop,but its use is limited due to serious pollen contamination problems.There are many studies on pollen development in model plants,but few on flower crops such as lili...Lily(Lilium spp.)is an important horticultural crop,but its use is limited due to serious pollen contamination problems.There are many studies on pollen development in model plants,but few on flower crops such as lilies.Gibberellin(GA)is a large class of hormones and plays an important role in plant vegetative growth and reproductive development.GAMYB is a group of the R2R3-MYB family upregulated by gibberellin,and plays an important role in anther development.Here,we isolated a novel GAMYB,named LoMYB65,from lily,which was closely related to the AtMYB65 and AtMYB33 in Arabidopsis.Fluorescence quantitative PCR results showed that LoMYB65 was mainly expressed in lily anthers.LoMYB65 could be activated by 288μmol·L^(-1)GA3treatment and the LoMYB65 protein was located in the nucleus and cytoplasm,and had transactivation in yeast and tobacco leaf cells.The conserved motif within 226 amino acids of the C-terminal of LoMYB65 contributed to its transactivation.Overexpression of LoMYB65 caused dwarf phenotype,unnormal tapetum development,less seeds of siliques in transgenic Arabidopsis plants,the transgenic plants showed partly male sterile.Simultaneously,silencing of LoMYB65 with VIGS(Virus Induced Gene Silencing)in lily anthers caused unnormal pollen development and reduced the pollen amount.Overexpression of LoMYB65 in Arabidopsis and silencing of LoMYB65 in lily resulted in decreased pollen counts,so we speculate that LoMYB65 may be dose-dependent.Overall,these findings suggest that LoMYB65 may play an important role in anther development and pollen formation in lily.LoMYB65 may provide a useful candidate gene for pollenless breeding of lily.展开更多
The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were i...The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this study.Results showed that the content of nutrients in bee pollen increased after wall disruption.Among them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher bioaccessibility.Antioxidant activities during in vitro digestion were also improved in walldisruption bee pollen.These findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.展开更多
The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed ...The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.展开更多
Background Understanding the mechanism of male sterility is crucial for producing hybrid seeds and developing sterile germplasm resources.However,only a few cytoplasmic male sterility(CMS)lines of cotton have been pro...Background Understanding the mechanism of male sterility is crucial for producing hybrid seeds and developing sterile germplasm resources.However,only a few cytoplasmic male sterility(CMS)lines of cotton have been produced due to several challenges,like inadequate variation of agronomic traits,incomplete sterility,weak resilience of restorer lines,and difficulty in combining strong dominance.Therefore,the morphological and cytological identification of CMS in cotton will facilitate hybrid breeding.Results Two F_(2) segregating populations of cotton were constructed from cytoplasmic male sterile lines(HaA and 01A,maternal)and restorer lines(HaR and 26R,paternal).Genetic analysis of these populations revealed a segregation ratio of 3:1 for fertile to sterile plants.Phenotypic analysis indicated no significant differences in traits of flower bud development between sterile and fertile plants.However,sterile plants exhibited smaller floral organs,shortened filament lengths,and anther atrophy on the flowering day in comparison with the fertile plants.When performed scanning electron microscopy(SEM),the two F_(2) populations revealed morphological variations in the anther epidermis.Cellular analysis showed no significant differences in pollen development before pollen maturation.Interestingly,between the pollen maturation and flowering stages,the tapetum layer of sterile plants degenerated prematurely,resulting in abnormal pollen grains and gradual pollen degradation.Conclusion The results of this study suggest that fertility-restoring genes are controlled by a single dominant gene.Sterile plants exhibit distinctive floral morphology,which is characterized by stamen atrophy and abnormal anthers.Pollen abortion occurs between pollen maturity and flowering,indicating that premature tapetum degradation may be the primary cause of pollen abortion.Overall,our study provides a theoretical basis for utilizing CMS in hybrid breeding and in-depth investigation of the dominant configuration of cotton hybrid combinations,mechanisms of sterility,and the role of sterile and restorer genes.展开更多
Food allergy as a global health problem threatens food industry.Bee pollen(BP)is a typical food with allergenic potentials,although it performs various nutritional/pharmacological functions to humans.In this study,lac...Food allergy as a global health problem threatens food industry.Bee pollen(BP)is a typical food with allergenic potentials,although it performs various nutritional/pharmacological functions to humans.In this study,lactic acid bacteria(LAB)were used to ferment Brassica napus BP for alleviating its allergenicity.Four novel allergens(glutaredoxin,oleosin-B2,catalase and lipase)were identified with significant decreases in LAB-fermented BP(FBP)than natural BP by proteomics.Meanwhile,metabolomics analysis showed significant increases of 28 characteristic oligopeptides and amino acids in FBP versus BP,indicating the degradation of LAB on allergens.Moreover,FBP showed alleviatory effects in BALB/c mice,which relieved pathological symptoms and lowered production of allergic mediators.Microbial high-throughput sequencing analysis showed that FBP could regulate gut microbiota and metabolism to strengthen immunity,which were closely correlated with the alleviation of allergic reactivity.These findings could contribute to the development and utilization of hypoallergenic BP products.展开更多
Ogura cytoplasmic male sterility(Ogura CMS)is extensively applied in hybrid seed production in cruciferous crops.However,the posttranscriptional molecular basis of Ogura CMS in cruciferous crops remains elusive.Here,a...Ogura cytoplasmic male sterility(Ogura CMS)is extensively applied in hybrid seed production in cruciferous crops.However,the posttranscriptional molecular basis of Ogura CMS in cruciferous crops remains elusive.Here,a data-independent acquisition-based proteomic approach coupled with a parallel reaction monitoring-based targeted proteomic assay was used to analyze the proteome dynamics of Ogura CMS cabbage line RM and its maintainer line RF during floral bud development to obtain insights into the mechanism underlying Ogura CMS in cruciferous crops.A total of 9162 proteins corresponding to 61464 peptides were identified in RM and RF floral buds.The proteomic fluctuation of RM was weaker than that of RF.Differences in protein expression between RM and RF gradually enlarged with floral bud development.Fifteen continually up-regulated and eight continually down-regulated proteins were found in RM relative to RF throughout floral bud development.Differentially expressed proteins between RM and RF during floral bud development were implicated in the endoplasmic reticulum(ER)-associated protein processing pathway,in which most of them exhibited down-regulated expression in RM.These data suggest that ER-associated protein processing may be involved in pollen abortion in Ogura CMS cabbage by inhibiting the expression of critical factors.Our findings not only deepen the understanding of the molecular mechanisms of Ogura CMS in cruciferous crops but also provide better guidance for applying Ogura CMS in the hybrid breeding of cruciferous crops.展开更多
Exine deprived pollen only coated with inline has been isolated and artificially germinated in Brassica L. In view of the lack of exine and germ furrows, the de-exined pollen is an interesting experimental system for ...Exine deprived pollen only coated with inline has been isolated and artificially germinated in Brassica L. In view of the lack of exine and germ furrows, the de-exined pollen is an interesting experimental system for studying pollen germination. This report focuses on the microscopic and ultrastructural changes in the aspects of polarization, predetermination of the germination site and new wall synthesis during the course of isolation and germination of the de-exined pollen. It was shown that the de-exined pollen was already in an active state and had established its polarity and germination sites prior to exine detachment. The germination sites were still localized at the region of the previous germ furrows even after exine detachment. The new wall deposited at the germination sites appeared to have an important morphogenetic role in setting a limit to the size of pollen tube diameter . These results support our assumption that the de-exined pollen may have an extensive application in the research of pollen biology.展开更多
The reconstruction of paleovegetation and paleoclimate requires an understanding of the relationships between surface pollen assemblages and modern vegetation and climate.Here,we analyzed the characteristics of surfac...The reconstruction of paleovegetation and paleoclimate requires an understanding of the relationships between surface pollen assemblages and modern vegetation and climate.Here,we analyzed the characteristics of surface pollen assemblages across different vegetation zones in the Tianshan Mountains.Using surface pollen analysis and vegetation sample surveys at 75 sites on the northern slopes of the Tianshan Mountains,we determined the correlation between the percentage of dominant pollen types and the corresponding vegetation cover.Redundancy analysis was used to investigate the relationships between surface pollen assemblages and environmental factors.Our results show that the Tianshan Mountains contain several distinct ecological regions,which can be divided into five main vegetation zones from low to high altitudes:mountain desert zone(Hutubi County(HTB):500-1300 m;Qitai County(QT):1000-1600 m),mountain steppe zone(HTB:1400-1600 m;QT:1650-1800 m),mountain forest zone(HTB:1650-2525 m;QT:1850-2450 m),subalpine meadow zone(HTB:2550-2600 m;QT:2500-2600 m),and alpine mat vegetation zone(HTB:2625-2700 m;QT:2625-2750 m).The surface pollen assemblages of different vegetation zones can accurately reflect the characteristics of the mountainous vegetation patterns on the northern slopes of the Tianshan Mountains when excluding the widespread occurrence of Chenopodiaceae,Artemisia,and Picea pollen.Both average annual precipitation(P_(ann))and annual average temperature(T_(ann))affect the distribution of surface pollen assemblages.Moreover,P_(ann) is the primary environmental factor affecting surface pollen assemblages in this region.A significant correlation exists between the pollen percentage and vegetation cover of Picea,Chenopodiaceae,Artemisia,and Asteraceae.Moreover,Picea,Chenopodiaceae,and Artemisia pollen are over-represented compared with their corresponding vegetation cover.The Asteraceae pollen percentage roughly reflects the distribution of a species within the local vegetation.These results have important implications for enhancing our understanding of the relationship between surface pollen assemblages and modern vegetation and climate.展开更多
Background Plant pollen has diverse morphological characteristics that can be consistently passed down from generation to generation.Information on pollen morphology is thus immensely important for plant classificatio...Background Plant pollen has diverse morphological characteristics that can be consistently passed down from generation to generation.Information on pollen morphology is thus immensely important for plant classification and identification.In the genus Gossypium,however,in-depth research on pollen morphology is lacking,with only few reports on limited cotton species.To evaluate the diversity of pollen in Gossypium,we therefore conducted a comprehensive analysis of the pollen morphology of 33 cotton species and varieties using scanning electron microscopy.Results The 33 analyzed cotton samples exhibited common pollen morphological features,including spherical shapes,radial symmetry,echination,panporation,and operculation,while the pollen size,spine shape,spine density and length showed distinctive features.Pollen size varied significantly among species,with diameters ranging from62.43 μm in G.harknessii to 103.41 μm in G.barbadense.The exine had an echinate sculptural texture,and spines were mostly conical or sharply conical but occasionally rod-like.Spine density varied from 173 in G.incanum to 54 in G.gossypioides,while spine length ranged from 3.53 μm in G.herbaceum to 9.47 μm in G.barbadense.In addition,the 33cotton species and varieties were grouped at a genetic distance of 3.83 into three clusters.Cluster Ⅰ comprised five allotetraploid AD-genome cotton species,four D-genome species,and one K-genome species.Cluster Ⅱ included 13diploid species from A,B,D,E,and G genomes,whereas Cluster Ⅲ only consisted one E-genome species G.incanum.Conclusions Although pollen characteristics alone are not enough to resolve taxonomic and systematic relationships within the genus Gossypium,our results add to knowledge on palynomorphology and contribute to phenological information on these taxa.Our findings should aid future systematic and phylogenetic studies of the Gossypium genus.展开更多
Arabinogalactan proteins(AGPs)are widely distributed in the plant kingdom and play a vital role during the process of plant sexual reproduction.In this study,we performed a comprehensive identification of the PbrAGPs ...Arabinogalactan proteins(AGPs)are widely distributed in the plant kingdom and play a vital role during the process of plant sexual reproduction.In this study,we performed a comprehensive identification of the PbrAGPs expressed in pear pollen and further explored their influences on pollen tube growth.Among the 187 PbrAGPs that were found to be expressed in pear pollen tubes,38 PbrAGPs were specifically expressed in pollen according to the RNA-seq data.The PbrAGPs were divided into two groups of highly expressed and specifically expressed in pear pollen.We further tested their expression patterns using RT-PCR and RT-qPCR.Most of the PbrAGPs were expressed in multiple tissues and their expression levels were consistent with reads per kilobase per million map reads(RPKM)values during pollen tube growth,implying that PbrAGPs might be involved in the regulation of pear pollen tube growth.We also constructed phylogenetic trees to identify the functional genes in pear pollen tube growth.Therefore,19 PbrAGPs(PbrAGP1 to PbrAGP19)were selected to test their influences on pollen tube growth.Recombinant proteins of the 19 PbrAGP-His were purified and used to treat pear pollen,and 11 of the PbrAGP-His recombinant proteins could promote pear pollen tube growth.Additionally,pollen tube growth was inhibited when the expression levels of PbrAGP1 and PbrAGP5 were knocked down using an antisense oligonucleotide assay.PbrAGP1 and PbrAGP5 were localized in the plasma membrane and might not alter the distribution of pectin in the pollen tube.In summary,this study identified the PbrAGPs expressed in pear pollen and lays the foundation for further exploring their functions in pollen tube growth.展开更多
Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen stora...Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains.This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids.Fresh pollens were collected from two Dioscorea alata males,then lyophilized(two lyophilization treatments were applied),followed by storage at room temperature(24℃–25℃)for 12 months.Moreover,the lyophilized and stored pollens were tested for viability by crossing with four female varieties.Our results showed that lyophilization is effective for achieving viable pollens after 12 months of storage.Treatment 1(48 h drying)showed higher pollen germination and fertility rates than Treatment 2(72 h drying).Although we observed a reduction in viability of lyophilized pollens after 12 months of storage,we generated hybrid seedlings with success rates from 12%to 21%compared to 21%–31%when using fresh pollens.Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings,which grew well in a greenhouse.Lyophilization is a practical approach for a long-term storage of greater yam pollen samples.This protocol will positively impact yam breeding programs particularly in developing countries.展开更多
The Tibetan Plateau ecosystem is fragile and sensitive to climate change. Understanding the relationships between modern pollen and the vegetation and climate of the region is critical for the evaluation of ecological...The Tibetan Plateau ecosystem is fragile and sensitive to climate change. Understanding the relationships between modern pollen and the vegetation and climate of the region is critical for the evaluation of ecological processes.Here, we explore modern pollen assemblages of typical land-cover types at a large spatial scale by analyzing 36surface samples from the southeastern Tibetan Plateau, supplemented by typical desert, desert-steppe, and steppe meadow transition data selected from the Chinese Surface Pollen Database, giving a total of 75 samples. We used redundancy analysis(RDA) to explore the responses of vegetation in the assemblages to regional climate. Our results show that pollen assemblages generally reflect the vegetation composition: assemblages from alpine meadow samples are dominated by Cyperaceae, Asteraceae, Rosaceae, and Polygonaceae;alpine shrublands mainly comprise Fabaceae, Rosaceae, Ericaceae, and Quercus(Q. spinosa);and coniferous forest surface samples mainly comprise Picea, Abies, Pinus, and Betulaceae. Our RDA shows that mean annual precipitation(MAP) is the main meteorological factor affecting the pollen assemblage and vegetation type;MAP positively correlates with percentages of Cyperaceae, Poaceae, Rosaceae, and Asteraceae, and negatively correlates with percentages of Chenopodiaceae, Ephedraceae, Nitraria, and Tamaricaceae. The ratio of Artemisia to Chenopodiaceae is a useful indicator to distinguish temperate desert from other land-cover types on the Tibetan Plateau, while the ratio of Cyperaceae + Asteraceae to Artemisia + Chenopodiaceae can be used to distinguish arid desert from other landcover types, and may provide a useful altitude index for the eastern Tibetan Plateau.展开更多
Wuren walnut is a unique germplasm resource of Juglans sigillata in Guizhou Province,named after its purple and black seed coat.It is a typical medicinal and edible plant with high nutritional value and good taste com...Wuren walnut is a unique germplasm resource of Juglans sigillata in Guizhou Province,named after its purple and black seed coat.It is a typical medicinal and edible plant with high nutritional value and good taste compared with ordinary walnut.The color of its inner seed coat is different from that of ordinary walnut,which is mostly light yellow.Wuren walnut has great market potential for development.To lay a theoretical foundation for the future breeding of improved varieties,pollination tree configuration,and hybrid breeding of Wuren walnut in Guizhou Province,this paper summarized the current research status of pollen vitality and stigma acceptability of Guizhou Wuren walnut in recent years,and looked forward to future research and application.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
[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in ...[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in solid media supplemented with five plant growth regulators （GA3 , NAA, 2, 4-D, 6-BA, IAA）. Then the rate of pollen germination and the length of pollen tube were respectively measured. [Result] In a certain concentration range, GA3 most significantly promoted the pollen germination and the pollen tube growth of Shushanggan, Kalayulvke, Dayoujia, Yiliakeyulvke and Kabakehuanna; NNA had the strongest improvement function on Kumaiti’s pollen germination and pollen tube growth. [Conclusion] All the five plant growth regulators promoted the pollen germination and the pollen tube growth of apricots at low concentration but inhibited them at high concentration.展开更多
53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in n...53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in northern China. The results show that 72% of the pollen taxa (80 taxa) are the same between the traps and the surface samples. The dominant taxa in the plant communities are consistent with the main pollen taxa in the pollen assemblages at the same sites. In Pinus plant communities, both Pinus pollen influx and concentration are higher, indicating the high pollen productivity and good pollen preservation ability of Pinus. In Picea and Abies plant communities, Picea and Abies have lower pollen influxes but higher concentrations, suggesting their low pollen productivities but better pollen preservation abilities. In Betula and Quercus plant communities, Betula and Quercus have higher pollen influxes but lower concentrations, revealing their high pollen productivities but poor pollen preservation abilities. The study of relationships between pollen and vegetation with discriminant analysis shows that pollen assemblages from both trap and surface samples can reflect the characteristics of different communities and distinguish different ecological areas, but surface samples can reflect the dominant components of communities much better than the traps. The study on correlations between pollen assemblages and climate with DCCA reveals that significant correlations exist between pollen assemblages and mean temperature of the coldest month (r = 0.84 for trap samples, r = 0.72 for surface samples), and then annual mean precipitation (r = 0.73 for trap samples, r = 0.71 for surface samples).展开更多
[Objective] The aim was to explore the most efficient medium for pollen germination and suitable pollen storage temperature for three different hawthorn species in Xinjiang, and to lay foundation for the development a...[Objective] The aim was to explore the most efficient medium for pollen germination and suitable pollen storage temperature for three different hawthorn species in Xinjiang, and to lay foundation for the development and utilization of wild hawthorn resources. [Method] A randomized block design was adopted to select the most suitable concentrations of sucrose and boric acid in the medium for pollen germination under in vitro culture. The vitality of the pollens stored at different tem- peratures for six mouths was measured once every 10 d using the optimum medi- um selected in above steps. [Result] The most efficient medium for Altai hawthorn pollen germination was 1% agar ＋ 0.05% boric acid ＋ 15% sucrose, and its germi- nation rate in this medium was 30.8%; the most suitable medium for crabapple hawthorn pollen germination was 1% agar ＋ 0.01% boric acid ＋ 15% sucrose, and its germination rate in this medium was 58.7%; and the highest germination rate of Junggar hawthorn pollen was found in the medium containing 1% agar ＋ 0.01% boric acid ＋ 20% sucrose, and the germination rate reached 67.2%. There were extremely significant differences （P〈0.01） in germination rate between these treat- ments and others in each species. The pollen vitality of Altai hawthorn, crabapple hawthorn and Junggar hawthorn were lost completely after they were stored at room temperature for 40, 60 and 70 d; at 4-5 ℃ for 90, 130, and 140 d; or at -18 ℃ for 130, 160 and 170 d. Therefore, -18 ℃ was found the most efficient storage temperature for the three hawthorn species＇ pollen among the three different stor- age temperatures. [Conclusion] A certain concentration of sucrose and boric acid can promote pollen germination of the three hawthorn species. Under different stor- age temperatures, the pollen vitality of the three hawthorn species can maintain for a longer period at -18 ℃ than at 4-5 ℃, and for the shortest period at room tem- perature.展开更多
基金supported by the National Natural Science Foundation of China(grant numbers 42171157,42107475 and 41907379)College Students'Innovation and Entrepreneurship Program of Nantong University,and Foundation of Hunan Province(2023JJ40099 and 23B0678)。
文摘Understanding the distribution,dispersal,and correlation of modern pollen with vegetation in mountainous regions is essential for establishing accurate modern analogs for fossil pollen records.This study,conducted in Leigong Mountain on the YunnanGuizhou Plateau of southwestern China,involved the collection of 35 surface soil samples from diverse vegetation communities along an elevational gradient ranging from 1210 to 1875 meters.The results reveal a close correspondence between modern pollen assemblages and vegetation zones.Principal Component Analysis(PCA)results indicate that pollen assemblages can effectively distinguish between subtropical montane evergreen broad-leaved forest(SEBF)and subtropical montane deciduous broadleaved forest(SDBF).However,both SEBF and SDBF show significant overlap with subtropical montane evergreen-deciduous broad-leaved mixed forest(SEMF).Detrended Correspondence Analysis(DCA)results clearly distinguish the three vegetation zones,and the first axis of DCA shows a significant positive correlation with elevation(p<0.01,R=0.48).Discriminant Analysis(DA)successfully assigns 94.4%of the modern pollen samples to their respective vegetation zones.Pollen taxa such as Impatiens,Astertype,and Rosaceae exhibit significant indicative capabilities for the SEBF zone,effectively distinguishing this vegetation zone from others.Pinus and Alnus display overrepresentation in the Leigong Mountain region,while Quercus(D,deciduous-type)and Poaceae exhibit high representation in the SEBF zone.In the SEBF zone,both pollen diversity and richness are the lowest.Our study reveals the complex relationship between the richness and diversity of pollen and vegetation.The diversity and richness of tree and shrub pollen are found to be lower than those of the corresponding plants.The pollen-vegetation relationship elucidated in this study serves as a critical reference for reconstructing ancient environments from fossil pollen retrieved in this region.
基金support from the National Key Research and Development Program of China(2022YFD1602000)the National Natural Science Foundation of China(32202514,U22A20498 and 32072596)+2 种基金the Joint Fund of Henan Province Science and Technology Research and Development Plan,China(222103810009)the Science and Technology Innovation Team of Shaanxi,China(2021TD-32)the China Postdoctoral Science Foundation(2022M711064 and 2023M741062).
文摘Watermelon(Citrullus lanatus)holds global significance as a fruit with high economic and nutritional value.Exploring the regulatory network of watermelon male reproductive development is crucial for developing male sterile materials and facilitating cross-breeding.Despite its importance,there is a lack of research on the regulation mechanism of male reproductive development in watermelon.In this study,we identified that ClESR2,a VIIIb subclass member in the APETALA2/Ethylene Responsive Factor(AP2/ERF)superfamily,was a key factor in pollen development.RNA insitu hybridization confirmed significantClESR2 expression in the tapetum and pollen during the later stage of anther development.The pollens of transgenic plants showed major defects in morphology and vitality at the late development stage.The RNA-seq and protein interaction assay confirmed that ClESR2 regulates pollen morphology and fertility by interacting with key genes involved in pollen development at both transcriptional and protein levels.These suggest that Enhancer of Shoot Regeneration 2(ESR2)plays an important role in pollen maturation and vitality.This study helps understand the male reproductive development of watermelon,providing a theoretical foundation for developing male sterile materials.
基金supported by the National Natural Science Foundation of China(Grant No.32101489)Forestry Science and Technology Innovation Program of Hunan Province(Grant No.XLK202101-2)Science and Technology Innovation Platform and Talent Program of Hunan Province(Grant Nos.2023RC3164,2021NK1007)。
文摘Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.
基金supported by the National Key Research and Development Program of China(2022YFD1200500)the Fundamental Research Funds for the Central Universities(KYZZ2022004)+1 种基金the Project for Crop Germplasm Resources Conservation of Jiangsu(2021-SJ-011)the High Level Talent Project of the Top Six Talents in Jiangsu(NY-077)。
文摘Lily(Lilium spp.)is an important horticultural crop,but its use is limited due to serious pollen contamination problems.There are many studies on pollen development in model plants,but few on flower crops such as lilies.Gibberellin(GA)is a large class of hormones and plays an important role in plant vegetative growth and reproductive development.GAMYB is a group of the R2R3-MYB family upregulated by gibberellin,and plays an important role in anther development.Here,we isolated a novel GAMYB,named LoMYB65,from lily,which was closely related to the AtMYB65 and AtMYB33 in Arabidopsis.Fluorescence quantitative PCR results showed that LoMYB65 was mainly expressed in lily anthers.LoMYB65 could be activated by 288μmol·L^(-1)GA3treatment and the LoMYB65 protein was located in the nucleus and cytoplasm,and had transactivation in yeast and tobacco leaf cells.The conserved motif within 226 amino acids of the C-terminal of LoMYB65 contributed to its transactivation.Overexpression of LoMYB65 caused dwarf phenotype,unnormal tapetum development,less seeds of siliques in transgenic Arabidopsis plants,the transgenic plants showed partly male sterile.Simultaneously,silencing of LoMYB65 with VIGS(Virus Induced Gene Silencing)in lily anthers caused unnormal pollen development and reduced the pollen amount.Overexpression of LoMYB65 in Arabidopsis and silencing of LoMYB65 in lily resulted in decreased pollen counts,so we speculate that LoMYB65 may be dose-dependent.Overall,these findings suggest that LoMYB65 may play an important role in anther development and pollen formation in lily.LoMYB65 may provide a useful candidate gene for pollenless breeding of lily.
基金the Program of State Key Laboratory of Food Science and Technology,Nanchang University (SKLF-ZZB-202119)。
文摘The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this study.Results showed that the content of nutrients in bee pollen increased after wall disruption.Among them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher bioaccessibility.Antioxidant activities during in vitro digestion were also improved in walldisruption bee pollen.These findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.
基金supported by National Natural Science Foundation of China(Nos.31871861 and 31501548)The Apicultural Industry Technology System(NCYTI-43-KXJ17)The Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2015-IAR)。
文摘The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.
基金supported by the Fund for the Biological Breeding-Major Projects in National Science and Technology(2023ZD04038)the Key Project for Agricultural Breakthrough in Core Technology of Xinjiang Production and Construction Crops(NYHXGG,2023AA102)the Key Project for Science and Technology Development of Shihezi city,Xinjiang Production and Construction Crops(2022NY01)。
文摘Background Understanding the mechanism of male sterility is crucial for producing hybrid seeds and developing sterile germplasm resources.However,only a few cytoplasmic male sterility(CMS)lines of cotton have been produced due to several challenges,like inadequate variation of agronomic traits,incomplete sterility,weak resilience of restorer lines,and difficulty in combining strong dominance.Therefore,the morphological and cytological identification of CMS in cotton will facilitate hybrid breeding.Results Two F_(2) segregating populations of cotton were constructed from cytoplasmic male sterile lines(HaA and 01A,maternal)and restorer lines(HaR and 26R,paternal).Genetic analysis of these populations revealed a segregation ratio of 3:1 for fertile to sterile plants.Phenotypic analysis indicated no significant differences in traits of flower bud development between sterile and fertile plants.However,sterile plants exhibited smaller floral organs,shortened filament lengths,and anther atrophy on the flowering day in comparison with the fertile plants.When performed scanning electron microscopy(SEM),the two F_(2) populations revealed morphological variations in the anther epidermis.Cellular analysis showed no significant differences in pollen development before pollen maturation.Interestingly,between the pollen maturation and flowering stages,the tapetum layer of sterile plants degenerated prematurely,resulting in abnormal pollen grains and gradual pollen degradation.Conclusion The results of this study suggest that fertility-restoring genes are controlled by a single dominant gene.Sterile plants exhibit distinctive floral morphology,which is characterized by stamen atrophy and abnormal anthers.Pollen abortion occurs between pollen maturity and flowering,indicating that premature tapetum degradation may be the primary cause of pollen abortion.Overall,our study provides a theoretical basis for utilizing CMS in hybrid breeding and in-depth investigation of the dominant configuration of cotton hybrid combinations,mechanisms of sterility,and the role of sterile and restorer genes.
基金supported by the National Natural Science Foundation of China(32102605)the Agricultural Science and Technology Innovation Program under Grant(CAAS-ASTIP-2020-IAR)。
文摘Food allergy as a global health problem threatens food industry.Bee pollen(BP)is a typical food with allergenic potentials,although it performs various nutritional/pharmacological functions to humans.In this study,lactic acid bacteria(LAB)were used to ferment Brassica napus BP for alleviating its allergenicity.Four novel allergens(glutaredoxin,oleosin-B2,catalase and lipase)were identified with significant decreases in LAB-fermented BP(FBP)than natural BP by proteomics.Meanwhile,metabolomics analysis showed significant increases of 28 characteristic oligopeptides and amino acids in FBP versus BP,indicating the degradation of LAB on allergens.Moreover,FBP showed alleviatory effects in BALB/c mice,which relieved pathological symptoms and lowered production of allergic mediators.Microbial high-throughput sequencing analysis showed that FBP could regulate gut microbiota and metabolism to strengthen immunity,which were closely correlated with the alleviation of allergic reactivity.These findings could contribute to the development and utilization of hypoallergenic BP products.
基金supported by Heilongjiang Provincial Natural Science Foundation of China(Grant No.YQ2022C012)China Postdoctoral Science Foundation(Grant No.2022MD713728)+1 种基金Heilongjiang Provincial Postdoctoral Fund(Grant No.LBHZ21046)the Open Project of Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(Northeast Region),Ministry of Agriculture and Rural Affairs,and National Key Research and Development Program of China(Grant No.2023YFD1201501).
文摘Ogura cytoplasmic male sterility(Ogura CMS)is extensively applied in hybrid seed production in cruciferous crops.However,the posttranscriptional molecular basis of Ogura CMS in cruciferous crops remains elusive.Here,a data-independent acquisition-based proteomic approach coupled with a parallel reaction monitoring-based targeted proteomic assay was used to analyze the proteome dynamics of Ogura CMS cabbage line RM and its maintainer line RF during floral bud development to obtain insights into the mechanism underlying Ogura CMS in cruciferous crops.A total of 9162 proteins corresponding to 61464 peptides were identified in RM and RF floral buds.The proteomic fluctuation of RM was weaker than that of RF.Differences in protein expression between RM and RF gradually enlarged with floral bud development.Fifteen continually up-regulated and eight continually down-regulated proteins were found in RM relative to RF throughout floral bud development.Differentially expressed proteins between RM and RF during floral bud development were implicated in the endoplasmic reticulum(ER)-associated protein processing pathway,in which most of them exhibited down-regulated expression in RM.These data suggest that ER-associated protein processing may be involved in pollen abortion in Ogura CMS cabbage by inhibiting the expression of critical factors.Our findings not only deepen the understanding of the molecular mechanisms of Ogura CMS in cruciferous crops but also provide better guidance for applying Ogura CMS in the hybrid breeding of cruciferous crops.
基金National Natural Science Foundation of China Science Foundation of State Education Commission of China.
文摘Exine deprived pollen only coated with inline has been isolated and artificially germinated in Brassica L. In view of the lack of exine and germ furrows, the de-exined pollen is an interesting experimental system for studying pollen germination. This report focuses on the microscopic and ultrastructural changes in the aspects of polarization, predetermination of the germination site and new wall synthesis during the course of isolation and germination of the de-exined pollen. It was shown that the de-exined pollen was already in an active state and had established its polarity and germination sites prior to exine detachment. The germination sites were still localized at the region of the previous germ furrows even after exine detachment. The new wall deposited at the germination sites appeared to have an important morphogenetic role in setting a limit to the size of pollen tube diameter . These results support our assumption that the de-exined pollen may have an extensive application in the research of pollen biology.
基金supported by the National Natural Science Foundation of China(42071102).
文摘The reconstruction of paleovegetation and paleoclimate requires an understanding of the relationships between surface pollen assemblages and modern vegetation and climate.Here,we analyzed the characteristics of surface pollen assemblages across different vegetation zones in the Tianshan Mountains.Using surface pollen analysis and vegetation sample surveys at 75 sites on the northern slopes of the Tianshan Mountains,we determined the correlation between the percentage of dominant pollen types and the corresponding vegetation cover.Redundancy analysis was used to investigate the relationships between surface pollen assemblages and environmental factors.Our results show that the Tianshan Mountains contain several distinct ecological regions,which can be divided into five main vegetation zones from low to high altitudes:mountain desert zone(Hutubi County(HTB):500-1300 m;Qitai County(QT):1000-1600 m),mountain steppe zone(HTB:1400-1600 m;QT:1650-1800 m),mountain forest zone(HTB:1650-2525 m;QT:1850-2450 m),subalpine meadow zone(HTB:2550-2600 m;QT:2500-2600 m),and alpine mat vegetation zone(HTB:2625-2700 m;QT:2625-2750 m).The surface pollen assemblages of different vegetation zones can accurately reflect the characteristics of the mountainous vegetation patterns on the northern slopes of the Tianshan Mountains when excluding the widespread occurrence of Chenopodiaceae,Artemisia,and Picea pollen.Both average annual precipitation(P_(ann))and annual average temperature(T_(ann))affect the distribution of surface pollen assemblages.Moreover,P_(ann) is the primary environmental factor affecting surface pollen assemblages in this region.A significant correlation exists between the pollen percentage and vegetation cover of Picea,Chenopodiaceae,Artemisia,and Asteraceae.Moreover,Picea,Chenopodiaceae,and Artemisia pollen are over-represented compared with their corresponding vegetation cover.The Asteraceae pollen percentage roughly reflects the distribution of a species within the local vegetation.These results have important implications for enhancing our understanding of the relationship between surface pollen assemblages and modern vegetation and climate.
基金This research was supported by the grants from the National Natural Science Foundation of China(32072023)the Project of Sanya Yazhou Bay Science and Technology City(SCKJ-JYRC-2022-88).
文摘Background Plant pollen has diverse morphological characteristics that can be consistently passed down from generation to generation.Information on pollen morphology is thus immensely important for plant classification and identification.In the genus Gossypium,however,in-depth research on pollen morphology is lacking,with only few reports on limited cotton species.To evaluate the diversity of pollen in Gossypium,we therefore conducted a comprehensive analysis of the pollen morphology of 33 cotton species and varieties using scanning electron microscopy.Results The 33 analyzed cotton samples exhibited common pollen morphological features,including spherical shapes,radial symmetry,echination,panporation,and operculation,while the pollen size,spine shape,spine density and length showed distinctive features.Pollen size varied significantly among species,with diameters ranging from62.43 μm in G.harknessii to 103.41 μm in G.barbadense.The exine had an echinate sculptural texture,and spines were mostly conical or sharply conical but occasionally rod-like.Spine density varied from 173 in G.incanum to 54 in G.gossypioides,while spine length ranged from 3.53 μm in G.herbaceum to 9.47 μm in G.barbadense.In addition,the 33cotton species and varieties were grouped at a genetic distance of 3.83 into three clusters.Cluster Ⅰ comprised five allotetraploid AD-genome cotton species,four D-genome species,and one K-genome species.Cluster Ⅱ included 13diploid species from A,B,D,E,and G genomes,whereas Cluster Ⅲ only consisted one E-genome species G.incanum.Conclusions Although pollen characteristics alone are not enough to resolve taxonomic and systematic relationships within the genus Gossypium,our results add to knowledge on palynomorphology and contribute to phenological information on these taxa.Our findings should aid future systematic and phylogenetic studies of the Gossypium genus.
基金supported by the earmarked fund for China Agriculture Research System(CARS-28-37)the Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2022E21)+1 种基金the Youth Foundation of Shandong Institute of Pomology,China(GSS2022QN11)the Natural Science Foundation of Shandong Province,China(ZR2019BC075,ZR2020MC141,and ZR2021MC177)。
文摘Arabinogalactan proteins(AGPs)are widely distributed in the plant kingdom and play a vital role during the process of plant sexual reproduction.In this study,we performed a comprehensive identification of the PbrAGPs expressed in pear pollen and further explored their influences on pollen tube growth.Among the 187 PbrAGPs that were found to be expressed in pear pollen tubes,38 PbrAGPs were specifically expressed in pollen according to the RNA-seq data.The PbrAGPs were divided into two groups of highly expressed and specifically expressed in pear pollen.We further tested their expression patterns using RT-PCR and RT-qPCR.Most of the PbrAGPs were expressed in multiple tissues and their expression levels were consistent with reads per kilobase per million map reads(RPKM)values during pollen tube growth,implying that PbrAGPs might be involved in the regulation of pear pollen tube growth.We also constructed phylogenetic trees to identify the functional genes in pear pollen tube growth.Therefore,19 PbrAGPs(PbrAGP1 to PbrAGP19)were selected to test their influences on pollen tube growth.Recombinant proteins of the 19 PbrAGP-His were purified and used to treat pear pollen,and 11 of the PbrAGP-His recombinant proteins could promote pear pollen tube growth.Additionally,pollen tube growth was inhibited when the expression levels of PbrAGP1 and PbrAGP5 were knocked down using an antisense oligonucleotide assay.PbrAGP1 and PbrAGP5 were localized in the plasma membrane and might not alter the distribution of pectin in the pollen tube.In summary,this study identified the PbrAGPs expressed in pear pollen and lays the foundation for further exploring their functions in pollen tube growth.
基金financially supported by the AfricaYam Project(Grant OPP1052998-Bill and Melinda Gates Foundation).
文摘Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains.This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids.Fresh pollens were collected from two Dioscorea alata males,then lyophilized(two lyophilization treatments were applied),followed by storage at room temperature(24℃–25℃)for 12 months.Moreover,the lyophilized and stored pollens were tested for viability by crossing with four female varieties.Our results showed that lyophilization is effective for achieving viable pollens after 12 months of storage.Treatment 1(48 h drying)showed higher pollen germination and fertility rates than Treatment 2(72 h drying).Although we observed a reduction in viability of lyophilized pollens after 12 months of storage,we generated hybrid seedlings with success rates from 12%to 21%compared to 21%–31%when using fresh pollens.Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings,which grew well in a greenhouse.Lyophilization is a practical approach for a long-term storage of greater yam pollen samples.This protocol will positively impact yam breeding programs particularly in developing countries.
基金supported by the NSFC (42161144012, 42030505, 42271176, and 41972020)the Western Light Project of CAS (xbzgzdsys-202204)Youth Innovation Promotion Association of CAS (2022439)
文摘The Tibetan Plateau ecosystem is fragile and sensitive to climate change. Understanding the relationships between modern pollen and the vegetation and climate of the region is critical for the evaluation of ecological processes.Here, we explore modern pollen assemblages of typical land-cover types at a large spatial scale by analyzing 36surface samples from the southeastern Tibetan Plateau, supplemented by typical desert, desert-steppe, and steppe meadow transition data selected from the Chinese Surface Pollen Database, giving a total of 75 samples. We used redundancy analysis(RDA) to explore the responses of vegetation in the assemblages to regional climate. Our results show that pollen assemblages generally reflect the vegetation composition: assemblages from alpine meadow samples are dominated by Cyperaceae, Asteraceae, Rosaceae, and Polygonaceae;alpine shrublands mainly comprise Fabaceae, Rosaceae, Ericaceae, and Quercus(Q. spinosa);and coniferous forest surface samples mainly comprise Picea, Abies, Pinus, and Betulaceae. Our RDA shows that mean annual precipitation(MAP) is the main meteorological factor affecting the pollen assemblage and vegetation type;MAP positively correlates with percentages of Cyperaceae, Poaceae, Rosaceae, and Asteraceae, and negatively correlates with percentages of Chenopodiaceae, Ephedraceae, Nitraria, and Tamaricaceae. The ratio of Artemisia to Chenopodiaceae is a useful indicator to distinguish temperate desert from other land-cover types on the Tibetan Plateau, while the ratio of Cyperaceae + Asteraceae to Artemisia + Chenopodiaceae can be used to distinguish arid desert from other landcover types, and may provide a useful altitude index for the eastern Tibetan Plateau.
基金Supported by Guizhou Provincial Forestry Bureau Outstanding Youth Talent Training Special Fund Project(QLKH JZ[2022]05)National Natural Science(31860215)Guizhou Provincial Science and Technology Achievement Promotion Program(QKHCG[2020]1Y051)。
文摘Wuren walnut is a unique germplasm resource of Juglans sigillata in Guizhou Province,named after its purple and black seed coat.It is a typical medicinal and edible plant with high nutritional value and good taste compared with ordinary walnut.The color of its inner seed coat is different from that of ordinary walnut,which is mostly light yellow.Wuren walnut has great market potential for development.To lay a theoretical foundation for the future breeding of improved varieties,pollination tree configuration,and hybrid breeding of Wuren walnut in Guizhou Province,this paper summarized the current research status of pollen vitality and stigma acceptability of Guizhou Wuren walnut in recent years,and looked forward to future research and application.
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Supported by Key Technology Integration and Demonstration of Xinjiang Characteristic Fruit Trees'High Efficiency and Safe Production,Science and Technical Plan Project of Xinjiang Uygur Autonomous Region(201130102)Key Technology Integration and Demonstration of Xinjiang Apricot Industrial Development,Science and Technical Plan Project of Xinjiang Uygur Autonomous Region(200931101)Financial Support from Xinjiang Uygur Autonomous Region Fruit Trees Key Subject~~
文摘[Objective] This study aimed to investigate the influence of different plant growth regulators on apricot pollen germination and pollen tube growth. [Method] Pollens of six kinds of Xinjiang apricots were cultured in solid media supplemented with five plant growth regulators （GA3 , NAA, 2, 4-D, 6-BA, IAA）. Then the rate of pollen germination and the length of pollen tube were respectively measured. [Result] In a certain concentration range, GA3 most significantly promoted the pollen germination and the pollen tube growth of Shushanggan, Kalayulvke, Dayoujia, Yiliakeyulvke and Kabakehuanna; NNA had the strongest improvement function on Kumaiti’s pollen germination and pollen tube growth. [Conclusion] All the five plant growth regulators promoted the pollen germination and the pollen tube growth of apricots at low concentration but inhibited them at high concentration.
基金Preliminary Special Foundation for National Key Basic Research of China, No.2003CCA01800Key National Natural Science Foundation of China, No.40730103+3 种基金National Natural Science Foundation of China, No.40672107 No.40571166Natural Science Foundation of Hebei Province, No.D2008000186 No.D2009000300
文摘53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in northern China. The results show that 72% of the pollen taxa (80 taxa) are the same between the traps and the surface samples. The dominant taxa in the plant communities are consistent with the main pollen taxa in the pollen assemblages at the same sites. In Pinus plant communities, both Pinus pollen influx and concentration are higher, indicating the high pollen productivity and good pollen preservation ability of Pinus. In Picea and Abies plant communities, Picea and Abies have lower pollen influxes but higher concentrations, suggesting their low pollen productivities but better pollen preservation abilities. In Betula and Quercus plant communities, Betula and Quercus have higher pollen influxes but lower concentrations, revealing their high pollen productivities but poor pollen preservation abilities. The study of relationships between pollen and vegetation with discriminant analysis shows that pollen assemblages from both trap and surface samples can reflect the characteristics of different communities and distinguish different ecological areas, but surface samples can reflect the dominant components of communities much better than the traps. The study on correlations between pollen assemblages and climate with DCCA reveals that significant correlations exist between pollen assemblages and mean temperature of the coldest month (r = 0.84 for trap samples, r = 0.72 for surface samples), and then annual mean precipitation (r = 0.73 for trap samples, r = 0.71 for surface samples).
基金Supported by Special Fund for Forestry-scientific Research in the Public Interest(201404722)Xinjiang Uygur Autonomous Region Fruit Trees Key Subject~~
文摘[Objective] The aim was to explore the most efficient medium for pollen germination and suitable pollen storage temperature for three different hawthorn species in Xinjiang, and to lay foundation for the development and utilization of wild hawthorn resources. [Method] A randomized block design was adopted to select the most suitable concentrations of sucrose and boric acid in the medium for pollen germination under in vitro culture. The vitality of the pollens stored at different tem- peratures for six mouths was measured once every 10 d using the optimum medi- um selected in above steps. [Result] The most efficient medium for Altai hawthorn pollen germination was 1% agar ＋ 0.05% boric acid ＋ 15% sucrose, and its germi- nation rate in this medium was 30.8%; the most suitable medium for crabapple hawthorn pollen germination was 1% agar ＋ 0.01% boric acid ＋ 15% sucrose, and its germination rate in this medium was 58.7%; and the highest germination rate of Junggar hawthorn pollen was found in the medium containing 1% agar ＋ 0.01% boric acid ＋ 20% sucrose, and the germination rate reached 67.2%. There were extremely significant differences （P〈0.01） in germination rate between these treat- ments and others in each species. The pollen vitality of Altai hawthorn, crabapple hawthorn and Junggar hawthorn were lost completely after they were stored at room temperature for 40, 60 and 70 d; at 4-5 ℃ for 90, 130, and 140 d; or at -18 ℃ for 130, 160 and 170 d. Therefore, -18 ℃ was found the most efficient storage temperature for the three hawthorn species＇ pollen among the three different stor- age temperatures. [Conclusion] A certain concentration of sucrose and boric acid can promote pollen germination of the three hawthorn species. Under different stor- age temperatures, the pollen vitality of the three hawthorn species can maintain for a longer period at -18 ℃ than at 4-5 ℃, and for the shortest period at room tem- perature.
