The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity,which can positively affect fitness and adaptability to environmental changes.While inbreeding generally reduces th...The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity,which can positively affect fitness and adaptability to environmental changes.While inbreeding generally reduces the proportion of heterozygous individuals in a population,polyploidy tends to increase the proportion.North American Populus tremuloides is one of the most widely distributed and ecologically important tree species in the Northern Hemisphere.However,genetic variation in Mexican populations of P.tremuloides,including the genetic signatures of their adaptation to a variety of environments,remains largely uncharacterized.The aim of this study was to analyze how inbreeding coefficient(FIS)and ploidy are associated with clonal richness,population cover,climate and soil traits in 91 marginal to small,isolated populations of this tree species throughout its entire distribution in Mexico.Genetic variables were determined using 36,810 filtered SNPs derived from genome re-sequencing.We found that FIS was approximately between 0 and e1,indicating an extreme heterozygosity excess.One key contributor to the observed extreme heterozygosity excess was asexual reproduction,although ploidy levels cannot explain this excess.Analysis of all neutral SNPs showed that asexual reproduction was positively correlated with observed heterozygosity(Ho)but negatively correlated with expected heterozygosity(He).Analysis of outlier SNPs also showed that asexual reproductionwas positively correlated with Ho and negatively correlated with He,although this latter correlation was not significant.These findings support the presence of a Meselson effect.展开更多
Triploid oysters are widely cultured due to their superior growth compared to diploids.However,differences in tempera-ture-salinity adaptation between di-and triploid oysters remain inconclusive.This study compared th...Triploid oysters are widely cultured due to their superior growth compared to diploids.However,differences in tempera-ture-salinity adaptation between di-and triploid oysters remain inconclusive.This study compared the survival rates,antioxidant en-zyme activities,and gene expressions in di-and triploid Pacific oyster Crassostrea gigas cultured in different temperatures(17,20,23,26,and 29℃)and salinities(18,22,26,30,and 34).Results showed that the optimum survival condition for both di-and triploids is 23℃/30.At 23℃,triploids exhibited significantly higher superoxide dismutase activity and lower heat shock protein 70(Hsp70)expression than diploids.At 29℃,triploids exhibited significantly higher survival rates than diploids.Across varying tem-peratures,triploids demonstrated significantly higher survival rates and antioxidant enzyme activities,along with lower malondialdehyde(MDA)levels and Hsp70 expression compared to diploids.The overall results demonstrate that triploids have a more robust antioxidant ca-pacity,reduced oxidative damage,and lower mortality than diploids under temperature treatments.Additionally,at a salinity of 18,triploids showed significantly higher catalase(CAT)level than diploids.Across varying salinities,triploids maintained lower MDA levels.These results suggest that triploids possess a stronger antioxidant defense under salinity treatments.In conclusion,triploid C.gigas demonstrates superior adaptation to diverse temperature and salinity conditions over diploids and are recommended for culture to improve oyster production.展开更多
In recent years,the quality of people's lives has gradually improved,and people pay more attention to the rationality of food nutrition.Green and healthy aquatic products,as representative of high-protein and low-...In recent years,the quality of people's lives has gradually improved,and people pay more attention to the rationality of food nutrition.Green and healthy aquatic products,as representative of high-protein and low-fat foods,are increasingly sought after by people.Triploid rainbow trout(Oncorhynchus mykiss)is rich in multiple unsaturated fatty acids and trace elements,which have rich nutrition and delicate flesh,its market demand is increasing.Triploid rainbow trout aquaculture has gradually become a characteristic economic industry in China.The triploid rainbow trout is favored by farmers because of its fast growth rate,delicious meat and large population.However,the development of triploid rainbow trout aquaculture is also restricted by many problems,such as unreasonable breeding management,high feed cost and low processing efficiency.Based on the research reports of domestic and foreign experts and scholars,this paper summarized the research progress of triploid rainbow trout,analyzed the influence of different farming models,nutritional needs,disease prevention on the triploid rainbow trout industry,and put forward suggestions for the development of triploid rainbow trout industry in order to provide scientific reference for the further development of triploid rainbow trout farming technology in China.展开更多
[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, r...[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.展开更多
The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of pla...The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of plants, such as concentration of plant growth regulators, leaf explant orientation, leaf growth sequence and leaf segment, were studied. The results indicated that the differentiation rate of adventitious shoots was 90% on basal MS medium only supplemented with 1 5?mg·L -1 BA (6 benzyladenine) and reached the highest level(95%) when 1 0?mg·L -1 BA and 0 3?mg·L -1 NAA (naphthaleneacetic acid) were added to MS medium. 90% of differentiation rate of adventitious roots were obtained when 0 3?mg·L -1 NAA was only added to MS medium. It was also found that more adventitious shoots were regenerated from the lower segment of leaf (with petiole) than the other segments, the number of adventitious shoots decreased from top to base of leaf growth sequence and the percentage of adventitious shoot induction with adaxial side downward was higher than that with adaxial side upward.展开更多
[ Objective] This study is to provide basis for the genetic improvement of triploid watermelon cultivars from seed coat characteristiscs by analyzing its genetic properties. [ Method ] Genetic effects of seed coat cha...[ Objective] This study is to provide basis for the genetic improvement of triploid watermelon cultivars from seed coat characteristiscs by analyzing its genetic properties. [ Method ] Genetic effects of seed coat characteristics and their related characteristics in tdploid watermelon were analyzed by additive dominant genetic model based on 36 F1 hybrids which were crossed by six female parents of four ecotypes and six male parents of same ecotype according to North Carolina II crossing design. [ Result] The seed coat number characteristics was controlled by additive effects, dominant effects and error variance of genetic together. The additive effects of the length and width of abortive seed coat were significant, and the error variance was significant or highly significant. It was observed that there was a significant negative correlation of additive effects between the seed coat number and fringe soluble sugar. Also there was a significant negative correlation of dominant effects between lycopenes, dry matter and the seed coat number. However, there was a highly significant positive correlation in additive effects between the length and width of abortive seed coat. [ Conclusion ] The results provide guidance for genetic breeding of triploid watermelon cultivars.展开更多
[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, disso...[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, dissociated and stained for preparing the glass slide to reveal the chromosome number via the microscopic examination; the sparse cells with good chromosome morphology were photographed under microscope. [ Result ]Allium macrostemon Bunge in Laizhou City introduced in this study was tdploid; its somatic chromosome number was 24 and karyotype formula was K（2n） =3x=24m（2SAT） ＋ 1Bs, thus the karyotype belongs to 1A type. One of the chromosome No. 3 contained satellite, and chromosome deletion may be existed in one of the chromosome No. 5. In addition, B chromosome was observed in some cells.[ Conclusion] This introduction of triploid A. macrostemon found in China was the first time.展开更多
The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood...The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood density and some mechanical properties. The results showed that significant or extremely significant difference in air dried wood density and the mechanical properties existed among the clones, this means these wood properties were under moderate or strong genetic controls and could be improved by genetic manipulations. The radial and vertical variation patterns of air dried wood density were also studied and the results were found to coordinate with other previous research results. The vertical variation patterns of most mechanical properties within the individual tree also conformed to the general wood theories except the modulus of elasticity and cross section hardness. Among the mechanical properties, modulus of elasticity (MOE) and tangent section hardness were under strong genetic control, with the clonal repeatabilities being 0 90 and 0 80, respectively. However, the clonal repeatabilities of other mechanical properties under study were a little lower than above two indexes. Genetic correlation analysis indicated that super clonal selection and breeding for veneer timber could be realized through indirect selection of wood density and form indexes.展开更多
Oranges are classified as the most traded fruit variety worldwide.The diversification of the varietal profile of this group is among the objectives of the Citrus breeding program.So,the creation of new triploid hybrid...Oranges are classified as the most traded fruit variety worldwide.The diversification of the varietal profile of this group is among the objectives of the Citrus breeding program.So,the creation of new triploid hybrids via immature embryos rescue,can lead to an increase in gene pool and produce seedless varieties.In addition,flow cytometry was successfully used for analyzing ploidy levels and genetic origin of triploid plants.The present study was aimed at optimizing immature embryos in vitro germination and plantlet development based on medium chemical composition of the two orange varieties,Pineapple and Parson Brown.When the fruit gets matured,they are harvested and the seeds extracted are classified according to their size.Only those which are small are cultured in a sterile Murashige and Tucker(MT)basal medium.The different concentrations of growth regulators are put to the test in order to gain the best medium for seeds development.M1(MT+1 mg/L gibberellic acid(GA3)),M2(MT+1 mg/L kenitin+0.5 mg/L 6-benzylaminopurine(BAP)+0.1 naphthalene acetic acid(NAA)),M3(MT+25 mg/L adenine sulfate(ADS)),M4(MT+0.5 mg/L kenitin+0.5 mg/L BAP+1 mg/L GA3).Percentage of germinated embryos(PGE)is the highest in M3 with 100%and 90%for both Pineapple and Parson Brown varieties,respectively.In addition,the germination interval average(GIA)is shorter in M1 for both varieties,which takes 6 d and 7 d,respectively.As regard to speed seedling growth(mm/week),both varieties undergo significant change in all four mediums.Similarly,the highest rate of acclimatization for the Pineapple and Parson Brown varieties is 80%and 90%in M1.In general,the smaller the embryos are,the more sensitive they are to culture medium composition.It is therefore essential to optimize the medium components in order to stimulate their in vitro development.Therefore,M1(MT+1 mg/L GA3)remains the best to promote short term good germination and produce a better rate of acclimatization.展开更多
The manipulation of the chromosome set for commercially valuable marine animals is important for enhancing aquacultural production. In this study, triploid and tetraploid sea cucumber Apostichopus japonicus were induc...The manipulation of the chromosome set for commercially valuable marine animals is important for enhancing aquacultural production. In this study, triploid and tetraploid sea cucumber Apostichopus japonicus were induced by hydrostatic pressure shock, and the conditions of appropriate induction were tested with different starting times, and hydrostatic pressure intensities and durations. The highest rate of triploid induction reached 20% and that of tetraploid was 60%. In consideration of the survival rate and hatch rate, the appropriate treatment for triploid was 55 Mpa of hydrostatic pressure for 5 rain at 55 min after fertilization （a.f.）, while for tetraploid it was 60 Mpa for 5 rain at 61 min a.f. The triploid of the sea cucumber could survive through the pelagic larval stage and attachment stage, and develop like the control group of the experiment. The tetraploid, however, could not survive the attachment stage.展开更多
The fine structure of the micropyle and the initial stages of sperm entry into the egg of the artificial multiple triploid carp were observed by means of scanning electron microscopy. Only one micropyle at the animal...The fine structure of the micropyle and the initial stages of sperm entry into the egg of the artificial multiple triploid carp were observed by means of scanning electron microscopy. Only one micropyle at the animal pole of the mature egg could be found. The aperture of the outer opening of the micropylar canal was only wide enough to admit one spermatozoon to pass through. A series of ordered sequence of motile events after fertilization were observed, which including that the sperm attached to the surface of the mature eggs and passed through micropylar canal, cottonlike substances closed up the micropylar canal, cortical vesicles underwent exocytosis and digesting, the vitelline envelope was transformed into fertilization envelope and so on. In addition, a preliminary discussion on the mechanism of polyspermic fertilization in the artificial multiple triploid carp was described in this paper.展开更多
The main taste components of triploid and diploid oyster (Crassostrea gigas) were compared. Free amino acids, inosine monophosphate, succinate, trimethylamine oxide and betaine in fresh and boiled extractives were ana...The main taste components of triploid and diploid oyster (Crassostrea gigas) were compared. Free amino acids, inosine monophosphate, succinate, trimethylamine oxide and betaine in fresh and boiled extractives were analyzed. The protein, lipids, glycogen, moisture and ash, which may affect the flavour, were evaluated. In boiled extractives, the amino acids were 394.1 mg(100 g) -1 in diploid and 183.5 mg(100 g) -1 in triploid. However, in fresh oyster extractives, they were 320.0 mg(100 g) -1 and 147.3 mg(100 g) -1 respectively. The inosine monophosphate in triploid was 44% more than that in diploid, and a little difference existed in the content of trimethylamine oxide between them. The contents of these taste components were the basis for taste flavour pattern determination.展开更多
Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru...Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru/C and a base,which afforded high yields of phenolic monomers from the lignin component and a solid carbohydrate pulp,is reported.The introduction of Cs_(2)CO_(3) led to the generation of C2 side‐chained phenols through the cleavage of C_(β)–O and C_(β)–C_(γ) bonds inβ–O–4 units in addition to C3 side‐chained phenols;the relationship between C2 and C3 was dependent on the base dosage.The reaction conditions,including base species,temperature,time,and H_(2) pressure,were optimized in terms of phenolic product distribution,delignification degree,and carbohydrate retention.The carbohydrate pulps generated from reductive catalytic fractionation in the presence of Cs_(2)CO_(3) were more amenable to enzymatic hydrolysis,indicating that this treatment of biomass constituted the fractionation of biomass components together with the breakdown of biomass recalcitrance.展开更多
A total of five pairs of diploidotriploid twin-seedlings （a diploid seedling and a triploid seedling emerged from a grain） were selected out from 4500 pairs of seedlings from SARII-628, a twin-seedling rice line. SS...A total of five pairs of diploidotriploid twin-seedlings （a diploid seedling and a triploid seedling emerged from a grain） were selected out from 4500 pairs of seedlings from SARII-628, a twin-seedling rice line. SSR analysis indicated that no difference between the diploid seedling and corresponding triploid seedling in a twin-seedling was found at the 310 loci, indicating that there was no obvious change in DNA primary structure. A modified AFLP technique ＇MSAP （methylation-sensitive AFLP）＇ was used to analyze methylation mutation. Although no methylation mutation was noted among the five diploids, 29 methylation mutation loci were found from the corresponding triploids. This suggested that methylation mutation happened rapidly on Mogeneration after natural homologous triploidization. The mutations were classified into 10 types, including 3 increased types, 3 decreased types and 4 undecided types of methylation-degrees. The bands of 22 loci were sequenced and then those sequences were searched through website. The result showed that the methylation mutation involved into the whole rice genome and the 12 pairs of chromosomes. The mutation trend was site-related and there were different mutation loci for different triploids, which foretold that SARII-628 would have different evolution fates after natural homologous triploidization.展开更多
Triploidy red sea bream were induced by cold shock techniques (0 3℃) in Qingdao in April 1994, May 1995 and May 1996. Normal diploidy and triploidy chromosome metaphases were produced by chromosome spreads from the g...Triploidy red sea bream were induced by cold shock techniques (0 3℃) in Qingdao in April 1994, May 1995 and May 1996. Normal diploidy and triploidy chromosome metaphases were produced by chromosome spreads from the gastrula. Counts of 104 chromosome metaphases of normal diploid showed each of them consisted of 2 acrocentric (st) and 46 telocentric (t) chromosomes. Based on the relative lengths and arm ratios, the 48 chromosomes were matched into 24 pairs. Counts of 107 chromosome metaphases of induced triploid showed that each metaphase consisted of 3 acrocentric (st) and 69 telocentric (t) chromosomes. The 72 chromosomes were easily matched into three sets of chromosomes, based on the relative lengths and arm ratios.展开更多
The glycogen content and the activities of two key enzymes in glycogen metabolism, glycogen phosphorylase and gly- cogen synthetase, in the gonad of diploid and triploid Pacific oysters (Crassostrea gigas) were compar...The glycogen content and the activities of two key enzymes in glycogen metabolism, glycogen phosphorylase and gly- cogen synthetase, in the gonad of diploid and triploid Pacific oysters (Crassostrea gigas) were compared during maturation. The glycogen content in the gonad of diploids decreased with gametogenesis (by 85.7%), but the glycogen content in the gonad of trip- loids did not vary significantly. Activity of glycogen phosphorylase (GP) in the gonad of diploids decreased with gametogenesis (by 55.5%), while GP activity of triploids did not vary significantly during maturation. Activity of glycogen synthetase (GS) in the gonad of diploids increased slightly with gametogenesis, reaching a peak in June. Activity of GS declined sharply from June to July, which might be due to gonad spawning. GS activity of triploid oysters in spawning time (July and August) was significantly higher than that in other months, which might be explained with a ‘compensating’ mechanism for the higher glycogen content in triploids.展开更多
基金We thank the Mexican Consejo Nacional de Humanidades,Ciencias y Tecnologías(CONAHCYT)for the financial support provided to the first author to carry out his training in the Institutional Doctoral Program in Agricultural and Forestry Sciences(PIDCAFUJED)with Scholarship No.334852financial support with agreement number CONACYT-FRQ-2016:279459 for the project“Genome-wide scans for detecting adaptation to climate and soil in Populus tremuloides as the most widely distributed tree species in North America”Dr.Jesús M.Olivas-García assisted in the sampling in the state of Chihuahua,Mexico,and Katrin Groppe,Thünen Institute of Forest Genetics,Germany,provided excellent lab work.The Emerging Leaders of the Americas Program(ELAP)of the Government of Canada awarded a scholarship and the Institute of Integrative and Systems Biology(IBIS)of Laval University allowed the use of its campus and contributed to the training of the first author.
文摘The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity,which can positively affect fitness and adaptability to environmental changes.While inbreeding generally reduces the proportion of heterozygous individuals in a population,polyploidy tends to increase the proportion.North American Populus tremuloides is one of the most widely distributed and ecologically important tree species in the Northern Hemisphere.However,genetic variation in Mexican populations of P.tremuloides,including the genetic signatures of their adaptation to a variety of environments,remains largely uncharacterized.The aim of this study was to analyze how inbreeding coefficient(FIS)and ploidy are associated with clonal richness,population cover,climate and soil traits in 91 marginal to small,isolated populations of this tree species throughout its entire distribution in Mexico.Genetic variables were determined using 36,810 filtered SNPs derived from genome re-sequencing.We found that FIS was approximately between 0 and e1,indicating an extreme heterozygosity excess.One key contributor to the observed extreme heterozygosity excess was asexual reproduction,although ploidy levels cannot explain this excess.Analysis of all neutral SNPs showed that asexual reproduction was positively correlated with observed heterozygosity(Ho)but negatively correlated with expected heterozygosity(He).Analysis of outlier SNPs also showed that asexual reproductionwas positively correlated with Ho and negatively correlated with He,although this latter correlation was not significant.These findings support the presence of a Meselson effect.
基金supported by grants from the Key R&D Program of Shandong Province(No.2022LZGCQY010)the National Natural Science Foundation of China(No.32373115)the China Agriculture Research System Project(No.CARS-49).
文摘Triploid oysters are widely cultured due to their superior growth compared to diploids.However,differences in tempera-ture-salinity adaptation between di-and triploid oysters remain inconclusive.This study compared the survival rates,antioxidant en-zyme activities,and gene expressions in di-and triploid Pacific oyster Crassostrea gigas cultured in different temperatures(17,20,23,26,and 29℃)and salinities(18,22,26,30,and 34).Results showed that the optimum survival condition for both di-and triploids is 23℃/30.At 23℃,triploids exhibited significantly higher superoxide dismutase activity and lower heat shock protein 70(Hsp70)expression than diploids.At 29℃,triploids exhibited significantly higher survival rates than diploids.Across varying tem-peratures,triploids demonstrated significantly higher survival rates and antioxidant enzyme activities,along with lower malondialdehyde(MDA)levels and Hsp70 expression compared to diploids.The overall results demonstrate that triploids have a more robust antioxidant ca-pacity,reduced oxidative damage,and lower mortality than diploids under temperature treatments.Additionally,at a salinity of 18,triploids showed significantly higher catalase(CAT)level than diploids.Across varying salinities,triploids maintained lower MDA levels.These results suggest that triploids possess a stronger antioxidant defense under salinity treatments.In conclusion,triploid C.gigas demonstrates superior adaptation to diverse temperature and salinity conditions over diploids and are recommended for culture to improve oyster production.
基金Supported by Tianjin Science and Technology Plan Projects(22ZYCGSN00050,22ZYCGSN0024023ZYCGSN00350,23ZYCGSN00310,24ZYCGSN00080)+3 种基金Gansu Provincial Science and Technology Plan(22CX8NE20823CXND0002)Gannan Prefecture Science and Technology Plan Project(2023ZZ1NC006)Tianjin Education Commission Research Program Project(2022ZD004)。
文摘In recent years,the quality of people's lives has gradually improved,and people pay more attention to the rationality of food nutrition.Green and healthy aquatic products,as representative of high-protein and low-fat foods,are increasingly sought after by people.Triploid rainbow trout(Oncorhynchus mykiss)is rich in multiple unsaturated fatty acids and trace elements,which have rich nutrition and delicate flesh,its market demand is increasing.Triploid rainbow trout aquaculture has gradually become a characteristic economic industry in China.The triploid rainbow trout is favored by farmers because of its fast growth rate,delicious meat and large population.However,the development of triploid rainbow trout aquaculture is also restricted by many problems,such as unreasonable breeding management,high feed cost and low processing efficiency.Based on the research reports of domestic and foreign experts and scholars,this paper summarized the research progress of triploid rainbow trout,analyzed the influence of different farming models,nutritional needs,disease prevention on the triploid rainbow trout industry,and put forward suggestions for the development of triploid rainbow trout industry in order to provide scientific reference for the further development of triploid rainbow trout farming technology in China.
基金Supported by National Key Technology R&D Program during the 11th Five-year Plan Period(2006BAD32B01)~~
文摘[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.
文摘The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of plants, such as concentration of plant growth regulators, leaf explant orientation, leaf growth sequence and leaf segment, were studied. The results indicated that the differentiation rate of adventitious shoots was 90% on basal MS medium only supplemented with 1 5?mg·L -1 BA (6 benzyladenine) and reached the highest level(95%) when 1 0?mg·L -1 BA and 0 3?mg·L -1 NAA (naphthaleneacetic acid) were added to MS medium. 90% of differentiation rate of adventitious roots were obtained when 0 3?mg·L -1 NAA was only added to MS medium. It was also found that more adventitious shoots were regenerated from the lower segment of leaf (with petiole) than the other segments, the number of adventitious shoots decreased from top to base of leaf growth sequence and the percentage of adventitious shoot induction with adaxial side downward was higher than that with adaxial side upward.
文摘[ Objective] This study is to provide basis for the genetic improvement of triploid watermelon cultivars from seed coat characteristiscs by analyzing its genetic properties. [ Method ] Genetic effects of seed coat characteristics and their related characteristics in tdploid watermelon were analyzed by additive dominant genetic model based on 36 F1 hybrids which were crossed by six female parents of four ecotypes and six male parents of same ecotype according to North Carolina II crossing design. [ Result] The seed coat number characteristics was controlled by additive effects, dominant effects and error variance of genetic together. The additive effects of the length and width of abortive seed coat were significant, and the error variance was significant or highly significant. It was observed that there was a significant negative correlation of additive effects between the seed coat number and fringe soluble sugar. Also there was a significant negative correlation of dominant effects between lycopenes, dry matter and the seed coat number. However, there was a highly significant positive correlation in additive effects between the length and width of abortive seed coat. [ Conclusion ] The results provide guidance for genetic breeding of triploid watermelon cultivars.
基金Supported by the Program from Ludong University(043312)~~
文摘[Objective]The study was to analyze the karyotype of Allium macrostemon Bunge in Laizhou City of Shandong Province.[ Method] The root tip of A. macrostemon was pretreated with 8-hydroxyquinoline solution, fixed, dissociated and stained for preparing the glass slide to reveal the chromosome number via the microscopic examination; the sparse cells with good chromosome morphology were photographed under microscope. [ Result ]Allium macrostemon Bunge in Laizhou City introduced in this study was tdploid; its somatic chromosome number was 24 and karyotype formula was K（2n） =3x=24m（2SAT） ＋ 1Bs, thus the karyotype belongs to 1A type. One of the chromosome No. 3 contained satellite, and chromosome deletion may be existed in one of the chromosome No. 5. In addition, B chromosome was observed in some cells.[ Conclusion] This introduction of triploid A. macrostemon found in China was the first time.
文摘The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood density and some mechanical properties. The results showed that significant or extremely significant difference in air dried wood density and the mechanical properties existed among the clones, this means these wood properties were under moderate or strong genetic controls and could be improved by genetic manipulations. The radial and vertical variation patterns of air dried wood density were also studied and the results were found to coordinate with other previous research results. The vertical variation patterns of most mechanical properties within the individual tree also conformed to the general wood theories except the modulus of elasticity and cross section hardness. Among the mechanical properties, modulus of elasticity (MOE) and tangent section hardness were under strong genetic control, with the clonal repeatabilities being 0 90 and 0 80, respectively. However, the clonal repeatabilities of other mechanical properties under study were a little lower than above two indexes. Genetic correlation analysis indicated that super clonal selection and breeding for veneer timber could be realized through indirect selection of wood density and form indexes.
文摘Oranges are classified as the most traded fruit variety worldwide.The diversification of the varietal profile of this group is among the objectives of the Citrus breeding program.So,the creation of new triploid hybrids via immature embryos rescue,can lead to an increase in gene pool and produce seedless varieties.In addition,flow cytometry was successfully used for analyzing ploidy levels and genetic origin of triploid plants.The present study was aimed at optimizing immature embryos in vitro germination and plantlet development based on medium chemical composition of the two orange varieties,Pineapple and Parson Brown.When the fruit gets matured,they are harvested and the seeds extracted are classified according to their size.Only those which are small are cultured in a sterile Murashige and Tucker(MT)basal medium.The different concentrations of growth regulators are put to the test in order to gain the best medium for seeds development.M1(MT+1 mg/L gibberellic acid(GA3)),M2(MT+1 mg/L kenitin+0.5 mg/L 6-benzylaminopurine(BAP)+0.1 naphthalene acetic acid(NAA)),M3(MT+25 mg/L adenine sulfate(ADS)),M4(MT+0.5 mg/L kenitin+0.5 mg/L BAP+1 mg/L GA3).Percentage of germinated embryos(PGE)is the highest in M3 with 100%and 90%for both Pineapple and Parson Brown varieties,respectively.In addition,the germination interval average(GIA)is shorter in M1 for both varieties,which takes 6 d and 7 d,respectively.As regard to speed seedling growth(mm/week),both varieties undergo significant change in all four mediums.Similarly,the highest rate of acclimatization for the Pineapple and Parson Brown varieties is 80%and 90%in M1.In general,the smaller the embryos are,the more sensitive they are to culture medium composition.It is therefore essential to optimize the medium components in order to stimulate their in vitro development.Therefore,M1(MT+1 mg/L GA3)remains the best to promote short term good germination and produce a better rate of acclimatization.
基金the National High-Tech Research and Development Program of China (863 Program, No.2506AA10A411)by the Dalian Natural Science Foundation (No. 99058)
文摘The manipulation of the chromosome set for commercially valuable marine animals is important for enhancing aquacultural production. In this study, triploid and tetraploid sea cucumber Apostichopus japonicus were induced by hydrostatic pressure shock, and the conditions of appropriate induction were tested with different starting times, and hydrostatic pressure intensities and durations. The highest rate of triploid induction reached 20% and that of tetraploid was 60%. In consideration of the survival rate and hatch rate, the appropriate treatment for triploid was 55 Mpa of hydrostatic pressure for 5 rain at 55 min after fertilization （a.f.）, while for tetraploid it was 60 Mpa for 5 rain at 61 min a.f. The triploid of the sea cucumber could survive through the pelagic larval stage and attachment stage, and develop like the control group of the experiment. The tetraploid, however, could not survive the attachment stage.
文摘The fine structure of the micropyle and the initial stages of sperm entry into the egg of the artificial multiple triploid carp were observed by means of scanning electron microscopy. Only one micropyle at the animal pole of the mature egg could be found. The aperture of the outer opening of the micropylar canal was only wide enough to admit one spermatozoon to pass through. A series of ordered sequence of motile events after fertilization were observed, which including that the sperm attached to the surface of the mature eggs and passed through micropylar canal, cottonlike substances closed up the micropylar canal, cortical vesicles underwent exocytosis and digesting, the vitelline envelope was transformed into fertilization envelope and so on. In addition, a preliminary discussion on the mechanism of polyspermic fertilization in the artificial multiple triploid carp was described in this paper.
基金supported by Shandong Natural Science Foundation(No.Y2001D06).
文摘The main taste components of triploid and diploid oyster (Crassostrea gigas) were compared. Free amino acids, inosine monophosphate, succinate, trimethylamine oxide and betaine in fresh and boiled extractives were analyzed. The protein, lipids, glycogen, moisture and ash, which may affect the flavour, were evaluated. In boiled extractives, the amino acids were 394.1 mg(100 g) -1 in diploid and 183.5 mg(100 g) -1 in triploid. However, in fresh oyster extractives, they were 320.0 mg(100 g) -1 and 147.3 mg(100 g) -1 respectively. The inosine monophosphate in triploid was 44% more than that in diploid, and a little difference existed in the content of trimethylamine oxide between them. The contents of these taste components were the basis for taste flavour pattern determination.
文摘Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru/C and a base,which afforded high yields of phenolic monomers from the lignin component and a solid carbohydrate pulp,is reported.The introduction of Cs_(2)CO_(3) led to the generation of C2 side‐chained phenols through the cleavage of C_(β)–O and C_(β)–C_(γ) bonds inβ–O–4 units in addition to C3 side‐chained phenols;the relationship between C2 and C3 was dependent on the base dosage.The reaction conditions,including base species,temperature,time,and H_(2) pressure,were optimized in terms of phenolic product distribution,delignification degree,and carbohydrate retention.The carbohydrate pulps generated from reductive catalytic fractionation in the presence of Cs_(2)CO_(3) were more amenable to enzymatic hydrolysis,indicating that this treatment of biomass constituted the fractionation of biomass components together with the breakdown of biomass recalcitrance.
文摘A total of five pairs of diploidotriploid twin-seedlings （a diploid seedling and a triploid seedling emerged from a grain） were selected out from 4500 pairs of seedlings from SARII-628, a twin-seedling rice line. SSR analysis indicated that no difference between the diploid seedling and corresponding triploid seedling in a twin-seedling was found at the 310 loci, indicating that there was no obvious change in DNA primary structure. A modified AFLP technique ＇MSAP （methylation-sensitive AFLP）＇ was used to analyze methylation mutation. Although no methylation mutation was noted among the five diploids, 29 methylation mutation loci were found from the corresponding triploids. This suggested that methylation mutation happened rapidly on Mogeneration after natural homologous triploidization. The mutations were classified into 10 types, including 3 increased types, 3 decreased types and 4 undecided types of methylation-degrees. The bands of 22 loci were sequenced and then those sequences were searched through website. The result showed that the methylation mutation involved into the whole rice genome and the 12 pairs of chromosomes. The mutation trend was site-related and there were different mutation loci for different triploids, which foretold that SARII-628 would have different evolution fates after natural homologous triploidization.
文摘Triploidy red sea bream were induced by cold shock techniques (0 3℃) in Qingdao in April 1994, May 1995 and May 1996. Normal diploidy and triploidy chromosome metaphases were produced by chromosome spreads from the gastrula. Counts of 104 chromosome metaphases of normal diploid showed each of them consisted of 2 acrocentric (st) and 46 telocentric (t) chromosomes. Based on the relative lengths and arm ratios, the 48 chromosomes were matched into 24 pairs. Counts of 107 chromosome metaphases of induced triploid showed that each metaphase consisted of 3 acrocentric (st) and 69 telocentric (t) chromosomes. The 72 chromosomes were easily matched into three sets of chromosomes, based on the relative lengths and arm ratios.
基金This study was supported by the 863 Program （2004AA603820 and 2006AA10A401）the National Natural Science Foundation （39900111 and 30771662）.
文摘The glycogen content and the activities of two key enzymes in glycogen metabolism, glycogen phosphorylase and gly- cogen synthetase, in the gonad of diploid and triploid Pacific oysters (Crassostrea gigas) were compared during maturation. The glycogen content in the gonad of diploids decreased with gametogenesis (by 85.7%), but the glycogen content in the gonad of trip- loids did not vary significantly. Activity of glycogen phosphorylase (GP) in the gonad of diploids decreased with gametogenesis (by 55.5%), while GP activity of triploids did not vary significantly during maturation. Activity of glycogen synthetase (GS) in the gonad of diploids increased slightly with gametogenesis, reaching a peak in June. Activity of GS declined sharply from June to July, which might be due to gonad spawning. GS activity of triploid oysters in spawning time (July and August) was significantly higher than that in other months, which might be explained with a ‘compensating’ mechanism for the higher glycogen content in triploids.
