Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utiliz...Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utilization,environmental friendliness,porosity,amphiphilicity,and strong adhesive properties.In addition,they display excellent biocompatibility and biodegradability,which significantly enhances the stability and targeting of drugs within the body.Spores and pollen can be extracted using methods such as acidic solutions,alkaline solutions,or enzyme treatments to obtain sporopollenin,which is an extremely resilient and chemically inert complex biopolymer.The sporopollenin extracted through this process removes the original bioactive substances,such as cell nuclei,enzymes,and DNA,providing greater drug loading capacity and containing no potential allergens or immunogens,thus further enhancing its drug loading capacity and improving safety in therapeutic applications.Due to these beneficial attributes,spores,pollen and sporopollenin have gained widespread use in a variety of drug delivery systems,such as targeted delivery,sustained drug delivery,toxicity mitigation,flavor masking,vaccine delivery,delivery of labile substances,and other applications.This review introduces the types of natural spores and pollen commonly used in drug delivery systems,including their main components,common effects,and uses in drug delivery systems,and so on.It subsequently summarizes novel optimization methods in their processing,such as physical treatment,surface modification,and chemical modification,which enable higher drug loading efficiency,stability,and targeting,among other benefits.Additionally,this paper reviews the research progress and applications of natural spores,pollen,and sporopollenin in drug delivery systems,while also touching on some innovative research content,such as novel nanomotor microcarriers developed based on pollen.Based on these research findings,we further elaborate on the advantages of spores,pollen,and sporopollenin in drug delivery systems.For example,they have high stability and drug loading capacity,good adhesion,excellent targeting,and are easy to modify functionally.Currently,they show promising prospects in the fields of targeted drug delivery,sustained-release drug delivery,as well as the delivery of drugs that are effective but slightly toxic,and are often used in research on the treatment of diseases such as cancer and inflammation.We have also highlighted the challenges they face in various applications and identified some issues that need to be addressed,including difficulties in largescale production,the need to improve extraction and purification processes,and the existence of a low but still noteworthy risk of allergies,in order to fully leverage their potential in drug delivery applications.According to current research,although spores,pollen,and sporopollenin face some unresolved issues in clinical drug delivery,they still have great potential overall and are expected to become a new generation of green drug delivery platforms.In the future,further research into their unique physical and chemical properties and structural characteristics will help develop more efficient and stable drug delivery systems to meet diverse treatment needs.We believe that continued exploration of natural spores,pollen,and sporopollenin will drive this emerging field to achieve continuous breakthroughs and progress,ultimately making an important contribution to the cause of human health.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
Kanamycin was used to screen To seeds of the variety Dongnong 46 transformed by means of pollen-tube method. The results showed that 400 mg·L^-1 kanamycin could inhibit growth of non-transgenic plants, and 2 posi...Kanamycin was used to screen To seeds of the variety Dongnong 46 transformed by means of pollen-tube method. The results showed that 400 mg·L^-1 kanamycin could inhibit growth of non-transgenic plants, and 2 positive plants were gotten combined with Gus dyeing and PCR detection. It is proved that this method is economic and effective in preliminary screening the transgenic plants.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
A group of red interbedded sandstone, siltstone and clay\|stone occur in the inland of northern Tibet. During the last 50 years, a lot of researches have been done at this group of beds along the Qinghai\|Xizang highw...A group of red interbedded sandstone, siltstone and clay\|stone occur in the inland of northern Tibet. During the last 50 years, a lot of researches have been done at this group of beds along the Qinghai\|Xizang highway in the Kekexili area.. According to the lithological characters, the strata have been divided into tow parts, the lower part named as the Feng huoshan group, and the upper part the Yaxicuo group. It is obscure to the age of the strata. For example, Yi jixiang et al. (1990) put them in early Pliocene in the light of the microfossils which they found at the foot of Feng huoshan mountain. The fossils include (1) Charophyta: Rhabdochara? sp ., Peckichara subsphecrica?, Cyrogoniae; (2) Ostracoda: Cypris sp .; (3) Gastropod: Sinoplanorbis sp ., Amnicola sp ., Bithynia sp .; and (4) Sporopollen: Tricoporopollenites nactonodus ?, Polypodiceoisporites, Cyathidites, Schizosporis, Pediastrum. Based on different species of Charophyta, Ostracoda, Gastropod, Bivalve, Sporopollen, Zhang Yifu et al. (1994) refer the strata to Cretaceous. The lower abundance of the fossils from previous research gave lower precision of fossil identification. Thus, the age of the strata was confusion.展开更多
Microscopic examination and AFLP molecular markers were employed to determine the incidence and related markers of 2n pollen (unreduced pollen) in Populus tomentosa Carr. The parallel and tripolar spindle at metaphase...Microscopic examination and AFLP molecular markers were employed to determine the incidence and related markers of 2n pollen (unreduced pollen) in Populus tomentosa Carr. The parallel and tripolar spindle at metaphase Ⅱ and the absence of cytokinesis at telophase Ⅱ led to the formation of 2n pollen. A group of 298 clones came from their indigenous areas was investigated for the production of 2n pollen based on the pollen size differences, within a clone and between n and 2n pollen. Pollen grains of 224 clones were collected, six of them only produced normal pollen, and the rest produced 2n pollen at different frequencies (0.6% -21.9%). Clones producing six normal and 22 2n pollen were selected for AFLP analysis. Following an initial screening with 55 primer combinations, the E50-M38 (CAT/ACT) primer was identified, which generated a PCR fragment (246 bp) from the normal clones, but not from the 2n pollen producers. In addition, the E31-M50 (AAA/CAT) amplified DNA fragment (204 bp) that was present in 2n pollen producers, and absent in normal clones. Two polymorphic bands were found and they were distinguished between normal and 2n pollen clones. They are very useful as AFLP markers for molecular-assisted selection in triploid breeding of 2n gametes in P.tomentosa.展开更多
Three 2x clones with 2n pollen production, BPH322,BPH325 and W5295,7, were each mated with three 4x cultivars, Raritan, Superior and Trent, in an incomplete diallel cross design. Estimates of various heritability for ...Three 2x clones with 2n pollen production, BPH322,BPH325 and W5295,7, were each mated with three 4x cultivars, Raritan, Superior and Trent, in an incomplete diallel cross design. Estimates of various heritability for tuber yield per plant are that h2m is 3720%,h2f 1630%,h2mf 2330%,h2B 7670% and h2N 5340%. Estimates of general combining ability(GCA) and specific combining ability(SCA) are 6960% and 3030%,respectively. The results suggest that additive effect of genes for tuber yield is obvious. The 2n pollen producing diploid hybrids have good breeding values for yield ,earliness and starch content.展开更多
The pollen tube pathway method of transformation has been reported to be successful in most crops, but less successfu in maizc. DNA can be transferred by cutting the stigma following pollination and applying the DNA s...The pollen tube pathway method of transformation has been reported to be successful in most crops, but less successfu in maizc. DNA can be transferred by cutting the stigma following pollination and applying the DNA solution in a suitable period DNA presumably reaches the ovary by flowing down the pollen tube and then integrates into the just fertilized but undivided zygotic cells. To provide the molecular evidence for this procedure, the plasmids pGBIRC carrying a CaMV35S promoter-PPT acetyle transferase （bar） gene-nos terminator genc fusion construct were used. Total 3 276 seeds were produced from the ears trcated with DNA. It was found that 35 scedlings were GUS assay positive, but less intense than that of the positive controls, of which 17 were PCR amplification positive. But, only 13 of the seeds from the plants treated with DNA containing the bar gene were found to be resistant compared with the negative control. Less than 1.07% of progeny seedlings tested cxpressed a herbicide positive reaction and polymerase chain reaction （PCR） with seedling DNA did detect the bar genc. Morphological variation was observed in six plants. We succeed in obtain PPT-resistant maize inbred lines via pollen tube pathway展开更多
Diploid hybrid derived from dihaploid Neo-tuberosum × Solanum phurejaand progeny of the diploid hybrid backcrossed to dihaploid Neo-tuberosum,which could produce 2n pollen, were crossed as male to S.tuberosumssp....Diploid hybrid derived from dihaploid Neo-tuberosum × Solanum phurejaand progeny of the diploid hybrid backcrossed to dihaploid Neo-tuberosum,which could produce 2n pollen, were crossed as male to S.tuberosumssp. tubersumc.v. NEA303. The performance of the 4x hybrids obtained from 4x × 2x cross was investigated for yield and yield components in the first year clonal generation. The 4x hybrids shown a drastic heterosis in plant height. Marketable yield/plant for the 4x hybrid was no better than that for the 4x cultivar, but the best hybrid individual of the two hybrid populations exceeded the best individual of the cultivar by 260 g/plant and 60 g/plant, respectively. Total yield/plant for the 4x hybrids performed drastic heterosis, however tuber number/plant was high and mean tuber weight low. These limit the use of 4x × 2x hybrids in potato breeding programs and need to be improved in near future.展开更多
为初步解析马尾松花粉对超低温保存的生理响应及相关代谢机制,该文以马尾松花粉为研究对象,在-196℃液氮进行超低温保存并分析冷存过程中[冻存前(CK)、液氮冻存后(LD)、化冻后(HD)]与活性氧(ROS)相关的生理指标及转录组数据。结果表明:...为初步解析马尾松花粉对超低温保存的生理响应及相关代谢机制,该文以马尾松花粉为研究对象,在-196℃液氮进行超低温保存并分析冷存过程中[冻存前(CK)、液氮冻存后(LD)、化冻后(HD)]与活性氧(ROS)相关的生理指标及转录组数据。结果表明:(1)马尾松花粉超低温保存的最适含水量为3.96%,该含水量下将花粉直接投入液氮保存至少48 h,冻存前后花粉存活率分别为78.54%和73.80%。(2)超氧化物歧化酶(SOD),抗坏血酸过氧化物酶(GSH),谷胱甘肽(APX),抑制羟自由基能力4个指标在冻存前后差异显著。(3)转录组测序共获得65.60 Gb过滤数据,有38505个基因比对到参考基因组(47.84%),CK vs LD、CK vs HD、LD vs HD的差异表达基因(DEGs数量分别为232个、268个、218个)。GO和KEGG分析表明,应激响应(response to stimulus)和抗氧化活性(antioxidant activity)等GO term显著富集;植物激素信号转导、MAPK信号途径、淀粉和蔗糖代谢、果糖和甘露醇代谢、过氧化物酶体等KEGG途径显著富集,从这些途径中进一步筛选到10个可能与冷冻保存过程中损伤和修复有关的基因。该研究结果为马尾松种质资源高效利用和安全保存提供了技术手段,也为进一步解析冷冻保存损伤的分子机制提供参考。展开更多
基金supported by a grant from The National Natural Science Foundation of China(32000997)。
文摘Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utilization,environmental friendliness,porosity,amphiphilicity,and strong adhesive properties.In addition,they display excellent biocompatibility and biodegradability,which significantly enhances the stability and targeting of drugs within the body.Spores and pollen can be extracted using methods such as acidic solutions,alkaline solutions,or enzyme treatments to obtain sporopollenin,which is an extremely resilient and chemically inert complex biopolymer.The sporopollenin extracted through this process removes the original bioactive substances,such as cell nuclei,enzymes,and DNA,providing greater drug loading capacity and containing no potential allergens or immunogens,thus further enhancing its drug loading capacity and improving safety in therapeutic applications.Due to these beneficial attributes,spores,pollen and sporopollenin have gained widespread use in a variety of drug delivery systems,such as targeted delivery,sustained drug delivery,toxicity mitigation,flavor masking,vaccine delivery,delivery of labile substances,and other applications.This review introduces the types of natural spores and pollen commonly used in drug delivery systems,including their main components,common effects,and uses in drug delivery systems,and so on.It subsequently summarizes novel optimization methods in their processing,such as physical treatment,surface modification,and chemical modification,which enable higher drug loading efficiency,stability,and targeting,among other benefits.Additionally,this paper reviews the research progress and applications of natural spores,pollen,and sporopollenin in drug delivery systems,while also touching on some innovative research content,such as novel nanomotor microcarriers developed based on pollen.Based on these research findings,we further elaborate on the advantages of spores,pollen,and sporopollenin in drug delivery systems.For example,they have high stability and drug loading capacity,good adhesion,excellent targeting,and are easy to modify functionally.Currently,they show promising prospects in the fields of targeted drug delivery,sustained-release drug delivery,as well as the delivery of drugs that are effective but slightly toxic,and are often used in research on the treatment of diseases such as cancer and inflammation.We have also highlighted the challenges they face in various applications and identified some issues that need to be addressed,including difficulties in largescale production,the need to improve extraction and purification processes,and the existence of a low but still noteworthy risk of allergies,in order to fully leverage their potential in drug delivery applications.According to current research,although spores,pollen,and sporopollenin face some unresolved issues in clinical drug delivery,they still have great potential overall and are expected to become a new generation of green drug delivery platforms.In the future,further research into their unique physical and chemical properties and structural characteristics will help develop more efficient and stable drug delivery systems to meet diverse treatment needs.We believe that continued exploration of natural spores,pollen,and sporopollenin will drive this emerging field to achieve continuous breakthroughs and progress,ultimately making an important contribution to the cause of human health.
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.
文摘Kanamycin was used to screen To seeds of the variety Dongnong 46 transformed by means of pollen-tube method. The results showed that 400 mg·L^-1 kanamycin could inhibit growth of non-transgenic plants, and 2 positive plants were gotten combined with Gus dyeing and PCR detection. It is proved that this method is economic and effective in preliminary screening the transgenic plants.
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.
文摘A group of red interbedded sandstone, siltstone and clay\|stone occur in the inland of northern Tibet. During the last 50 years, a lot of researches have been done at this group of beds along the Qinghai\|Xizang highway in the Kekexili area.. According to the lithological characters, the strata have been divided into tow parts, the lower part named as the Feng huoshan group, and the upper part the Yaxicuo group. It is obscure to the age of the strata. For example, Yi jixiang et al. (1990) put them in early Pliocene in the light of the microfossils which they found at the foot of Feng huoshan mountain. The fossils include (1) Charophyta: Rhabdochara? sp ., Peckichara subsphecrica?, Cyrogoniae; (2) Ostracoda: Cypris sp .; (3) Gastropod: Sinoplanorbis sp ., Amnicola sp ., Bithynia sp .; and (4) Sporopollen: Tricoporopollenites nactonodus ?, Polypodiceoisporites, Cyathidites, Schizosporis, Pediastrum. Based on different species of Charophyta, Ostracoda, Gastropod, Bivalve, Sporopollen, Zhang Yifu et al. (1994) refer the strata to Cretaceous. The lower abundance of the fossils from previous research gave lower precision of fossil identification. Thus, the age of the strata was confusion.
文摘Microscopic examination and AFLP molecular markers were employed to determine the incidence and related markers of 2n pollen (unreduced pollen) in Populus tomentosa Carr. The parallel and tripolar spindle at metaphase Ⅱ and the absence of cytokinesis at telophase Ⅱ led to the formation of 2n pollen. A group of 298 clones came from their indigenous areas was investigated for the production of 2n pollen based on the pollen size differences, within a clone and between n and 2n pollen. Pollen grains of 224 clones were collected, six of them only produced normal pollen, and the rest produced 2n pollen at different frequencies (0.6% -21.9%). Clones producing six normal and 22 2n pollen were selected for AFLP analysis. Following an initial screening with 55 primer combinations, the E50-M38 (CAT/ACT) primer was identified, which generated a PCR fragment (246 bp) from the normal clones, but not from the 2n pollen producers. In addition, the E31-M50 (AAA/CAT) amplified DNA fragment (204 bp) that was present in 2n pollen producers, and absent in normal clones. Two polymorphic bands were found and they were distinguished between normal and 2n pollen clones. They are very useful as AFLP markers for molecular-assisted selection in triploid breeding of 2n gametes in P.tomentosa.
文摘Three 2x clones with 2n pollen production, BPH322,BPH325 and W5295,7, were each mated with three 4x cultivars, Raritan, Superior and Trent, in an incomplete diallel cross design. Estimates of various heritability for tuber yield per plant are that h2m is 3720%,h2f 1630%,h2mf 2330%,h2B 7670% and h2N 5340%. Estimates of general combining ability(GCA) and specific combining ability(SCA) are 6960% and 3030%,respectively. The results suggest that additive effect of genes for tuber yield is obvious. The 2n pollen producing diploid hybrids have good breeding values for yield ,earliness and starch content.
文摘The pollen tube pathway method of transformation has been reported to be successful in most crops, but less successfu in maizc. DNA can be transferred by cutting the stigma following pollination and applying the DNA solution in a suitable period DNA presumably reaches the ovary by flowing down the pollen tube and then integrates into the just fertilized but undivided zygotic cells. To provide the molecular evidence for this procedure, the plasmids pGBIRC carrying a CaMV35S promoter-PPT acetyle transferase （bar） gene-nos terminator genc fusion construct were used. Total 3 276 seeds were produced from the ears trcated with DNA. It was found that 35 scedlings were GUS assay positive, but less intense than that of the positive controls, of which 17 were PCR amplification positive. But, only 13 of the seeds from the plants treated with DNA containing the bar gene were found to be resistant compared with the negative control. Less than 1.07% of progeny seedlings tested cxpressed a herbicide positive reaction and polymerase chain reaction （PCR） with seedling DNA did detect the bar genc. Morphological variation was observed in six plants. We succeed in obtain PPT-resistant maize inbred lines via pollen tube pathway
文摘Diploid hybrid derived from dihaploid Neo-tuberosum × Solanum phurejaand progeny of the diploid hybrid backcrossed to dihaploid Neo-tuberosum,which could produce 2n pollen, were crossed as male to S.tuberosumssp. tubersumc.v. NEA303. The performance of the 4x hybrids obtained from 4x × 2x cross was investigated for yield and yield components in the first year clonal generation. The 4x hybrids shown a drastic heterosis in plant height. Marketable yield/plant for the 4x hybrid was no better than that for the 4x cultivar, but the best hybrid individual of the two hybrid populations exceeded the best individual of the cultivar by 260 g/plant and 60 g/plant, respectively. Total yield/plant for the 4x hybrids performed drastic heterosis, however tuber number/plant was high and mean tuber weight low. These limit the use of 4x × 2x hybrids in potato breeding programs and need to be improved in near future.
文摘为初步解析马尾松花粉对超低温保存的生理响应及相关代谢机制,该文以马尾松花粉为研究对象,在-196℃液氮进行超低温保存并分析冷存过程中[冻存前(CK)、液氮冻存后(LD)、化冻后(HD)]与活性氧(ROS)相关的生理指标及转录组数据。结果表明:(1)马尾松花粉超低温保存的最适含水量为3.96%,该含水量下将花粉直接投入液氮保存至少48 h,冻存前后花粉存活率分别为78.54%和73.80%。(2)超氧化物歧化酶(SOD),抗坏血酸过氧化物酶(GSH),谷胱甘肽(APX),抑制羟自由基能力4个指标在冻存前后差异显著。(3)转录组测序共获得65.60 Gb过滤数据,有38505个基因比对到参考基因组(47.84%),CK vs LD、CK vs HD、LD vs HD的差异表达基因(DEGs数量分别为232个、268个、218个)。GO和KEGG分析表明,应激响应(response to stimulus)和抗氧化活性(antioxidant activity)等GO term显著富集;植物激素信号转导、MAPK信号途径、淀粉和蔗糖代谢、果糖和甘露醇代谢、过氧化物酶体等KEGG途径显著富集,从这些途径中进一步筛选到10个可能与冷冻保存过程中损伤和修复有关的基因。该研究结果为马尾松种质资源高效利用和安全保存提供了技术手段,也为进一步解析冷冻保存损伤的分子机制提供参考。
