Productive Traits and Triploid Rate Stability in Triploidy-Induced ‘Haida No. 2’ Strain of the Pacific Oyster, Crassostrea gigas

In order to evaluate the effects of triploidy induction on a selected strain‘Haida No.2’of the Pacific oyster Crassostrea gigas,which is characterized with golden shell color and high growth rate,the growth,survival rate and stability of triploid rate were analyzed at different development stages in the present study.Three different conditions inhibiting the release of polar body Ⅱ or polar body Ⅰ were tested:(A)Cytochalasin-B(CB),0.5mg L^(−1) at 10min post-insemination for 15 min;(B)CB,0.5mg L^(−1)at 15 min postinsemination for 20 min;and(C)CB,0.7mg L^(−1),at 15 min post-insemination for 20 min.The triploidy induction treatments significantly reduced the D-larvae and survival rates at the larvae stage but not at the juvenile and adult stages.Triploid rate dramatically decreased at the larval stage and did not significantly change at the juvenile and adult stages.Regarding the stability of the triploid rate,there was a significant difference between the three treatment groups.Larvae from the treatment A and control groups exhibited higher growth rates in shell height than those from the other two treatment groups at day 27.Triploid juveniles and adults from the treatment A group exhibited a higher wet weight than diploids from the control group and triploids from the other treatment groups.Triploidy induction did not affect the shell color of the progeny.The results obtained in the study demonstrate that triploidy induction has the potential to be used to increase the production of C.gigas variety‘Haida No.2’without modifying its golden shell color.

Selection of Media for Hardwood Cuttings Container Seedling-raising of Triploid Clones of Populus tomentosa

[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.

Establishment of in Vitro Regeneration System of Triploid Chinese White Poplar

初步建立了三倍体毛白杨 (PopulustomentosaCarr.)组织培养再生系统。组织培养时 ,外植体最好选用在弱光下从休眠芽上萌发的幼芽或嫩茎 ,经HgCl2 溶液表面消毒后 ,接种到大量元素减半、含 0 .2 5mg/L吲哚乙酸和 1.0 0mg/L玉米素的MS培养基上。试管苗的生根可采用含 0 .2 5mg/L吲哚丁酸和 10mg/L维生素B1的MS培养基。试管苗茎段的分化依无性系和外源激素条件的不同而异。无性系B19的茎段较易分化 ,而无性系B30 4和B331分化较难。最适的分化培养基为大量元素减半、含 0 .0 5～ 0 .10mg/L吲哚乙酸和 1.0

恩诺沙星对湘云鲫(Triploid crucian carp)组织转氨酶(GPT、GOT)活性的影响

采用胸腔注射法,研究了恩诺沙星对湘云鲫(Triploid crucian carp)组织谷草转氨酶(GOT)和谷丙转氨酶(GPT)活性的影响。结果显示,给药后5 d,各试验组GPT、GOT酶活性均升高,与对照组之间呈显著差异水平(P<0.05);给药后10 d,各浓度组GPT酶活性有所降低,而GOT酶活性则继续升高,鳃的GOT酶活性达到了最大值;给药后15、20 d,各浓度组GPT酶活性继续下降,而肝脏、肾脏GOT酶活性在给药后15 d时达到最大值,之后开始下降;给药后25 d,鳃的GPT酶活性除200 mg/kg组外都恢复至正常水平,而肝脏、肾脏各浓度组的GPT酶活性显著低于对照组(P<0.05),肝脏的GOT酶活性恢复到了正常水平,而鳃和肾脏的GOT酶活性略高于对照组水平。

Discovery of Triploid Allium macrostemon Bunge in Laizhou City of Shandong Province

[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.

Genetic Control of Air-Dried Wood Density, Mechanical Properties and Its Implication for Veneer Timber Breeding of New Triploid Clones in Populus tomentosa Carr

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.

Cytological Basis of Polyspermic Fertilizationin An Artificial Multiple Triploid Carp1

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.

Comparison of Taste Components between Triploid and Diploid Oyster

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.

Natural Homologous Triploidization and DNA Methylation in SARII-628,a Twin-seedling Line of Rice (Oryza sativa)

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.

PRELIMINARY STUDY ON CHROMOSOMES OF INDUCED TRIPLOID IN THE RED SEA BREAM, PAGROSOMUS MAJOR

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.

Seasonal Variation of the Glycogen Enzyme Activity in Diploid and Triploid Pacific Oyster Gonad During Sexual Maturation

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.

Transcriptomic Analysis of Pacific Oyster(Crassostrea gigas) Zygotes Under Hypotonic Triploid Induction

Polyploid breeding is widely used in various marine species. Low salinity treatment is an effective method of inducing triploid of bivalve mollusks. In this study, RNA-seq was performed to determine genes and pathways involved in hyposaline adaption and cell division of Pacific oyster(Crassostrea gigas) zygotes, trying to better understand the possible molecular mechanism of hypo-osmotic induction. A total of 26965 unigenes were generated in the de novo assembly of clean Illumina reads with an average length of 934 bp and N50 of 1721 bp. Of 3024 differentially expressed genes(DEGs), 2501 were up-regulated and 523 were downregulated. GO(Gene Ontology) annotation and KEGG(Kyoto Encyclopedia of Genes and Genomes) pathway analysis of these DEGs revealed that these DEGs participate a variety of biological processes including osmoregulation, cytoskeleton organization, cell survival and death, and substantially modulate cell proliferation and embryonic development. In summery, RNA-seq methodology was applied for the first time to demonstrate hypotonic-induced transcriptomic alteration in oyster zygotes. Our findings not only interpreted the relatively high mortality of induced larvae, but also provided a valuable reference for further investigations on the mechanism of hyposaline induction, thus should aid to the application of low salinity in triploid induction in large scale aquaculture in future.

Chromosome Behavior of Heat Shock Induced Triploid in Fenneropenaeus Chinensis

Triploidy was induced in Chinese shrimp Fenneropenaeus chinensis by 30±0.5℃heat shock treatment (initiated at 20 min after fertilization) for 10 min to inhibit the release of PB2 at 18.0℃. The highest triploid rate obtained was 84.5% in nauplius stage. The effect of heat shock treatment on meiosis and cleavage of eggs was investigated in this work aimed to establish efficient procedures for triploid induction and to gain understanding of the mechanism of triploid production. Three pronuclei that could be observed in the treated eggs under fluorescence microscope developed into triploid embryos. Some abnormal chromosome behavior was observed in heat shocked eggs.

Integration of Ru/C and base for reductive catalytic fractionation of triploid poplar

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.

Lignin Characterization of Triploid Clones of Populus tomentosa Carr.

In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.

Effects of Fertilization Treatments on Plantation Growth of Triploid Clones in Populus tomentosa

With four clones of triploid Populus tomentosa as materials, the effects of fertilization treatment on growth and physiological characters in terms of leaf nitrogen content, phosphorous content, potassium content, net photosynthetic rate, transpiration rate, water utilization efficiency and chlorophyll content have been studied. Compared with the general fertilizer as a control, the long-effect fertilizer, especially for Populus, produce more favorable results, for P. tomentosa on sandy land.

Analysis on Genetic Background of Female Triploid and Male Diploid Individuals of Siraitia grosvenorii by Using RAPD Molecular Markers

In order to provide molecular biological basis for breeding of excellent seedless varieties of Siraitia grosvenorii, the genetic background of 28 female triploid and male diploid individuals of S. grosvenorii was analyzed by using RAPD molecular markers. The results showed that female triploid and male diploid individuals of S. grosvenorli had abundant genetic background, with great genetic similarity cecfficients and close genetic distance. Overall, the genetic background of female triploid and male diploid individuals of S. grosvenorii exhibited relatively low complexity. Therefore, it is necessary to take corresponding measures for germplasm innovation to enrich the genetic background of seedless parents of S. grosvenorii.

Triploid Wild Rice (BKK) Strain Found in Bangkok Originated from Hybridizations among Three Parental <i>Oryza</i>Species

A wild rice (BKK) strain showing sterile spikelet and big leaves inhabited at the basin of the Chao Phraya river of Bangkok city, Thailand. The BKK strain was found as a natural triploid and thus its origin has been interested long time. Three different-sized fragments were amplified in RNA polymerase I largest subunit (PolA1) gene, which is a single-copy nuclear gene per haploid genome. Short type (0.14 kb) intron 20 sequence of BKK strain was identical to that of O. rufipogon and O. sativa. Phylogenetic analysis showed that long type (1.5 kb and 1.8 kb) intron 20 sequences of BKK strain were closely related to that of O. longistaminata and O. officinalis, respectively. We analyzed protein tag (Ptag) sequence encoded by exons 19 to 21 of PolA1 gene. Determined three Ptag sequences of BKK strain were identical to that of O. rufipogon, O. longistaminata, and O. officinalis, respectively. Relative DNA content of nuclei in O. officinalis and BKK strain was 1.5 and 1.75 times than that in O. sativa, respectively. And BKK strain contained CentO-C1 repeats, which were unique to O. officinalis. These results indicated that BKK strain comprised three genomes of O. rufipogon, O. longistaminata, and O. officinalis.

Investigation on Evolutionary Relationships of the Subgenomes in Interspecific Triploid Cotton via Meiotic FISH

We report in this paper primary studies on interspecific species of cotton vis GISH(genomic in situ hybridization).We use interspecific triploid hybrids(F1 from hybridization of allotetraploid cultivated species with diploid A,D,or C genome species) and two cultivated tetraploids to study

TRIPLOIDY INDUCTION IN PACIFIC OYSTER CRASSOSTREA GIGAS BY CAFFEINE WITH THERMAL SHOCK

Zygotes of Pacific oyster (Crassostrea gigas) were treated for triploid induction with caffeine (10 mmol/L, 15mmol/L and 20mmol/L) in combination with thermal shocks (at 40 minute post -fertilization) lasting for 5 and 10 minutes. The highest yield of triploids, 41. 5%, was obtained from the treatment with 20 mmol/L caffeine at 34℃ lasting 10 minutes. The triploid levels were less than 30. 0% in other treatments. Triploid indution was more effective in treatment with 15 - 20 mmol/L caffeine at 34 - 38℃ than with lower concentrations of caffeine at temperatures below 32℃. Our results suggest tha triploid induction with caffeine in combination with thermal shocks is less efficient than some other methods reported previously.