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.

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。

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.

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.

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.

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.

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.

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.

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.

THE FIBER MORPHOLOGY VARIATION OF TRIPLOID CLONE OF POPULUS TOMENTOSA CARR.AND ITS SUPPOSED HARVESTING AGE FOR THE PAPER INDUSTRY

The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.

COMPARISON OF APMP PULP CHARACTERISTICS OF JUVENILE TRIPLOID CHINESE WHITE POPLAR IN SALINE SOIL WITH THAT OF NORMAL 5-YEAR POPLAR

In the paper, differences between the juvenile Triploid Chinese White Poplar (TCWP) in saline soil and 5-year TCWP in normal soil are compared in terms of their APMP-pulping properties. The results show that the saline planting environment does not show obvious effects on pulping properties of juvenile TCWP.

RESEARCH ON FIBER MORPHOLOGY AND PULPING PROPERTIES OF THE TRIPLOID OF PLPULUS TOMENTOSA FROM PLANTATION AT DIFFERENT AGES

The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed that the difference of chemical compositions is not significant, and the extractive contents become bigger in some sort with age, the difference of length weighted mean length of fiber also is not significant, and coarseness of fiber has trend of augment by degree, while the fines content increases obviously with age. That difference of pulping properties between chemical pulping (KP process and Soda-AQ process) and chemimechanical pulping (SCMP process and APMP process) is not significant, which is consistent with the analysis of chemical composition and fiber morphology. Considering comprehensively, the tree age of 5 years is better for paper making industry, also the mixed pulping with different ages of the triploid of populus tomentosa is feasible with steady pulp quality.

柑橘2个三倍体有性后代群体果实品质性状的遗传特点

【目的】研究柑橘三倍体有性后代果实品质性状的遗传特点,为倍性杂交创制无核三倍体新种质科学选配亲本提供理论依据。【方法】以柑橘二倍体品种秋辉橘、清见橘橙为母本,异源四倍体体细胞杂种橘柚+甜橙(NS)、甜橙+红橘(SD)为父本倍性杂交获得的2个三倍体有性后代群体成熟果实为材料,通过测定其果实横纵径、单果质量、果皮厚度、可溶性固形物和可滴定酸含量等性状,探究柑橘三倍体有性后代果实品质性状的遗传特点。【结果】三倍体后代单果质量和果实横径平均值均介于双亲之间,呈趋中变异;果实纵径变化趋势在2个组合间有差异,秋辉橘×NS组合后代呈趋大变异,而清见橘橙×SD组合则呈趋中变异;果皮厚度平均值均大于亲中值且多数高于高值亲本,存在一定程度的超高亲本遗传现象;2个组合三倍体有性后代果实可溶性固形物含量平均低低亲比率分别为74.4%、66.88%,呈趋小变异;而2个三倍体有性后代群体果实可滴定酸含量平均值均低于亲中值,且不同年份间酸含量介于亲本间和低于低值亲本的后代比例较高。【结论】推测柑橘三倍体有性后代果实单果质量、果实横径、纵径、果形指数、果皮厚度和可溶性固形物含量性状是由多基因控制的数量性状,可滴定酸含量性状可能存在主效控制基因。

长牡蛎AMPK基因在三倍体性腺发育中的表达特性及调控机制

为探究三倍体长牡蛎(Crassostrea gigas)性腺发育的分子调控机制,对AMPK基因及其靶基因在长牡蛎性腺发育过程中的表达特性进行研究。长牡蛎AMPK包含AMPKα、AMPKβ和AMPKγ三个亚基。荧光定量PCR结果显示,这三个亚基的mRNA表达量在二倍体长牡蛎性腺发育过程中均呈下降趋势,在三倍体长牡蛎性腺发育过程中均呈上升趋势。二倍体长牡蛎性腺中AMPKα亚基Thr172位点磷酸化(p-AMPKα)水平在增殖期高,到成熟期几乎完全消失,这说明在长牡蛎性腺发育早期AMPK基因可能起到重要调控作用;在三倍体长牡蛎中,不育型三倍体(3nβ)的p-AMPKα水平显著高于可育型三倍体(3nα),推测AMPKα亚基磷酸化增强可能与三倍体不育密切相关。AMPKα亚基活性蛋白主要定位在滤泡细胞、精原/精母细胞和卵原/卵母细胞,说明该蛋白可能参与调控长牡蛎配子发生的早期过程。对AMPK潜在靶基因(GCS、CREB、SREBP1、ACC和Raptor)进行表达量分析,结果显示长牡蛎中p-AMPKα可能参与了CREB和SREBP1基因表达的调控。推测在可育型三倍体长牡蛎性腺发育早期AMPK基因可能调控促进糖原和脂质的分解,为生殖细胞分裂和分化提供能量;而在不可育型三倍体长牡蛎中由于生殖细胞分裂不旺盛,AMPK基因表达未被抑制,AMPK发挥维持体内能量稳态的调控作用。

金虎杂交斑三倍体血细胞特征及染色体核型分析

为了解三倍体金虎杂交斑(棕点石斑鱼Epinephelus fuscoguttatus♀×蓝身大斑石斑鱼E.tukula♂)的细胞遗传特性。以静水压休克诱导的三倍体金虎杂交斑为研究对象,通过细胞DNA含量测定鉴定出三倍体金虎杂交斑、对三倍体金虎杂交斑进行红细胞大小、形态的比较及染色体核型分析。结果显示,三倍体金虎杂交斑的DNA含量与二倍体金虎杂交斑的DNA含量的比值为1.45︰1。三倍体金虎杂交斑血细胞长轴、短轴分别为二倍体的1.34、1.14倍(P<0.01)。三倍体金虎杂交斑血细胞体积、表面积分别为二倍体的2.07和1.54倍(P<0.01),三倍体金虎杂交斑血细胞核长轴、短轴、核表面积、核体积分别为二倍体的1.22、1.05、1.29、1.57倍(P<0.01)。通过头肾-秋水仙素注射法进行染色体核型分析结果显示,二倍体金虎杂交斑的染色体数目为48,核型为2n=48=2sm+46t,NF=50,三倍体金虎杂交斑的染色体数目为72,核型为3n=72=1m+2sm+69t,NF=75,未发现有性染色体。实验结果为石斑鱼杂交种多倍体育种提供了丰富生物学基础数据。