基于多世代群体的甜瓜果实色泽和外形性状的遗传分析

探讨甜瓜果实色泽和外形性状的遗传规律,为甜瓜重要商品性的遗传改良提供理论依据。以薄皮甜瓜‘HB74’和厚皮甜瓜‘HNA24’为亲本构建F_1、F_2和BC_1群体,春秋两季对各群体的甜瓜果实皮色、果肉颜色、种皮颜色、果实形状、果面沟、果脐等6个性状进行统计分析。结果表明,果实皮色、果肉颜色和种皮颜色在F_2和BC_1群体中的分离比约为3∶1和1∶1,为一对基因控制的质量性状,深绿果皮、白果肉和浅黄种皮为显性;果实形状偏向共显性遗传,果面沟偏向显性遗传,而果脐偏向隐性遗传,但这3个性状的分离不完全符合单基因遗传。对重组性状的统计结果发现,果实皮色和果肉颜色呈连锁关系,而与种皮颜色独立。     

节瓜果皮颜色遗传规律的研究

用2个果皮青绿色自交系桂优1号毛节瓜、环江节瓜和1个果皮深绿色自交系七星节瓜作亲本,通过正、反交及回交组配,对其杂交组合(桂优1号毛节瓜×七星节瓜、环江节瓜×七星节瓜)的F1、F2、BC1和BC2各世代的果色进行统计.结果表明:F1果色表现一致,无论正、反交均表现为深绿色;F2果色无论正、反交都分离出深绿色和青绿色两种果色,且分离比率接近3:1;BC1(以深绿色的自交系作父本进行回交)果实颜色均表现为深绿色,BC2(以青绿色的自交系作父本进行回交)果实颜色则表现出深绿色和青绿色的分离,分离比率接近1:1.根据经典遗传学原理对节瓜果皮颜色的遗传效应进行了研究,初步推断出:节瓜果实的深绿色与青绿色受一对核基因控制,深绿色对青绿色为显性.     

甜瓜茎蔓苦味性状的遗传分析

甜瓜茎蔓苦味特征表现为茎蔓具有浓郁的苦味。通过对2组茎蔓具苦味与茎蔓无苦味甜瓜杂交F1、F2代及回交世代BC1、BC2的茎蔓苦味性状的分离观察研究表明,茎蔓苦味性状分离规律均符合孟得尔的3∶1和1∶1的遗传规律;说明茎蔓苦味性状是由1对核基因控制独立遗传的显性性状。该性状可作为苗期遗传标记性状,应用于甜瓜杂交育种和杂交一代品种纯度的早期鉴定。     

甜瓜果实颜色3 个质量性状基因的定位

 以甜瓜（Cucumis melo L.）黄绿皮、白肉、无覆纹的自交系‘K1-7’为母本,黄皮、橘红肉、 无覆纹的自交系‘K3-92-1’为父本杂交,组建F2 遗传群体,采用MSG（multiplexed shotgun genotyping） 法对F2 群体进行基因分型,并在甜瓜全基因组范围内扫描SNP 遗传标记。利用检测到的44 722 个SNP 标记位点进行高密度Bin 遗传图谱的构建,并对甜瓜果皮底色、覆纹颜色和果肉颜色等3 个质量性状进行 遗传分析和基因定位。结果表明,果皮底色和果肉颜色由单基因控制,黄绿果皮和橘红色果肉为显性性 状,果皮底色基因定位在4 号染色体409 828 ~ 835 625 bp 区间内,长度约为425 kb,果肉颜色基因定位 在9 号染色体20 433 942 ~ 20 573 889 bp 区间内,长度约为139 kb,覆纹颜色由两个有上位效应的基因控 制,其中1 个基因位点与果皮颜色控制位点在同一区域,1 个基因定位在2 号染色体末端23 736 803 ~ 23 787 235 bp 区间内,长度约为51 kb。     

甜瓜雄全同株与纯雌株基因遗传分析及初步定位

利用甜瓜纯雌系WI998与雄全同株品系TopMark配制杂交组合,通过对P1、P2、F1、F2、BC1P1、BC1P26个世代群体的遗传分析,对决定甜瓜性别表达基因进行研究;同时以F2分离群体为试材,采用SSR分子标记构建甜瓜遗传图谱,定位控制甜瓜性别表达基因。研究结果表明,控制甜瓜性别表达的基因有3个,分别为:雄全同株基因a、雌全同株基因g和纯雌系基因gy。初步构建了一个包括31个SSR标记和2个形态学标记的甜瓜遗传图谱,找到了两个与性别表达基因相关的SSR分子标记,其中MU55491与a基因的遗传距离为13.5cM,MU147232与gy基因的遗传距离为11.6cM。     

番茄绿果与红果颜色性状遗传的研究

以绿果番茄‘绿樱’和红果番茄‘TTD1003A’为亲本材料,构建4个世代P_1、P_2、F_1和F_2遗传群体,采用标准比色卡,对成熟果实的果色、果皮色、果肉色和胎座胶状物质颜色进行观察分析。结果表明:在F_2代分离群体中,果色分离比例为,红︰棕︰黄︰绿=9︰3︰3︰1;果皮色为,黄色︰透明=3︰1;果肉色为,红︰浅黄︰浅绿=12︰3︰1,即果色、果皮色和果肉色的遗传符合孟德尔遗传规律,且分别由两对、一对和两对核基因控制;果实绿色相对果实红色为隐性,果皮透明相对果皮黄色为隐性,果肉浅绿色相对果肉红色为隐性,果皮与果肉颜色独立遗传。同时,运用色差仪测定果实表面颜色的L值、a值和b值,计算色光值后,运用植物数量性状主基因+多基因遗传分析法分析得出:番茄果实绿色对红色的遗传可能符合两对加性—显性—上位性主基因+加性—显性多基因遗传(MX2-ADI-AD),其中两对主基因均以加性效应为主,第一对主基因的加性作用更为明显。在F_2代中,色差仪测定指标的主基因遗传率为76%~89%,而多基因遗传率接近0,即该组合控制果色性状的主基因遗传力很高,多基因遗传力很低,对番茄果色的选择应在分离早期世代进行。     

甜瓜PMR5抗白粉病基因的遗传定位

以甜瓜白粉病抗性品种PMR5,感白粉病甜瓜伽师及杂交F1以及BC1、BC2分离群体为试材,接种白粉菌生理小种1,采用抗病遗传分析,并利用BSA(Bulked Segregation Analysis)结合SSR(Simple Sequence Repeat)分子标记方法,研究抗白粉病基因的遗传规律获得与其连锁的分子标记,利用获得的分子标记对抗白粉病基因进行遗传定位。结果表明:BC1中抗病与感病分离比为64∶27,BC2中分离比为37∶27,推测PMR5在BC1中表现2个显性基因,在BC2中表现单显性基因遗传模式。用BC2对抗病基因进行遗传定位发现,一共有11个位于LGII的SSR分子标记与抗白粉病基因连锁,抗病基因位于标记CMGA36和SSR25208之间约104 113bp。     

黄瓜黑斑病抗性遗传分析

以感黑斑病自交系L63和抗黑斑病自交系L9为亲本建立了6个世代联合群体(P1、P2、F1、BC1S、BC1R、F2),采用植物数量性状主基因+多基因混合遗传模型对群体的黑斑病抗性进行多世代联合分析。结果表明,黄瓜抗黑斑病性状符合D-2遗传模型,受1对加性主基因+加性-显性多基因控制;BC1S、BC1R、F2的主基因遗传率分别为60.23%、60.23%、75.18%,多基因遗传率均为0。说明控制黄瓜黑斑病的抗性为主基因遗传,并且遗传稳定,环境方差占表型方差的比例大于24.82%、小于39.77%,也受到外界环境的影响。     

甜瓜‘PMR6’抗白粉病基因的遗传及其定位研究

以甜瓜(Cucumis melo L.)感白粉病品种‘Hami413’为受体亲本,抗白粉病品种‘PMR6’为供体亲本构建的255株BC2分离群体为材料,研究‘PMR6’抗白粉病的遗传规律及基因定位。群体遗传分析表明,BC2群体中对白粉病菌Podosphaera xanthii生理小种1的抗性由显性单基因控制,基因命名为Pm-PMR6-1;利用混合分组分析法(Bulked segregant analysis,BSA)从分布于甜瓜12个连锁群上的390个SSR分子标记中筛选出5个多态性标记;通过连锁分析,将该抗性基因定位于12号连锁群SSR标记DM0191与CMBR111之间;根据甜瓜基因组信息设计SSR引物,进一步将该基因定位于SSR12407与SSR12202之间,并且该抗性基因与标记Mu7191共分离;比对基因组序列,两标记间物理距离约226 kb,预测35个候选基因。     

甜瓜果肉β-胡萝卜素含量的遗传分析

以父本200932（果肉橙红色）与母本200930（果肉绿色）为亲本,建立了6个联合世代（P1、P2、F1、F2、BC1P1及BC2P2）群体,采用植物数量性状主基因+多基因混合遗传模型,进行多世代联合分析,探讨甜瓜果肉β-胡萝卜素含量性状的遗传特点。结果表明：组合200930×200932的β-胡萝卜素含量性状遗传受两对加性-显性-上位性主基因+加性-显性多基因模型（E-1）控制,F2群体主基因遗传率为92.66%,多基因遗传率为5.40%,BC1P1群体主基因遗传率为86.80%,多基因遗传率为0,BC2P2群体主基因遗传率为59.88%,多基因遗传率为38.60%。     

Relationship between renal hypertension and cardiac α1-adrenoceptor autoantibodies in rats

AIM: To examine the autoantibody against α₁-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α₁-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α₁-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α₁-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension.     

Influence of Mineral Nutrients on Strawberry Fruit Quality and Their Accumulation in Plant Organs

Abstract

This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality.     

Mixed-severity fire regime in a high-elevation forest of Grand Canyon,Arizona, USA

Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date.     

瓜叶绿素降解关键酶基因PPH和PAO cDNA片段的克隆与表达初步分析

 以西双版纳黄瓜和‘华黄5号’黄瓜叶片为试验材料,研究了衰老过程中两种黄瓜叶片叶绿素含量变化及脱镁叶绿素脱镁叶绿酸水解酶基因PPH和脱镁叶绿酸a加氧酶基因PAO的表达。结果表明：随着叶片衰老,叶绿素a和叶绿素b含量显著降低,叶绿素a与叶绿素b的比值在0.5左右,推测叶绿素b的含量可能对黄瓜叶片保绿起到重要作用。荧光定量RT-PCR分析结果显示：PPH和PAO在西双版纳黄瓜叶片生长35 d时表达量最高,分别为5.50和1.86;PPH在‘华黄5号’叶片35 d时表达量最高,为7.14,而PAO在35和45 d表达量都很高,分别为3.90和3.91;PPH和PAO在西双版纳黄瓜叶片中的表达量低于在‘华黄5号’中。     

Effects of simvastatin on PDGF-BB and serum-induced proliferation of vascular smooth muscle cells and on the expression of tumor suppressor gene PTEN

AIM:To observe the effect of simvastatin on the proliferation of vascular smooth muscle cells(VSMCs) induced by serum and growth factor PDGF-BB and the effect of simvastatin on the expression of PTEN,a important regulator of G₁/S cell cycle transition. METHODS:The DNA synthesis was determined by [³H]-TdR incorporation, cell cycle was examined with flow cytometry, the protein level of PTEN was measured by Western blot method. RESULTS: (1)Simvastatin inhibited [³H]-TdR incorporation in a dose dependent manner. (2) Flow cytometric DNA analysis revealed that simvastatin induced significantly enhancement of G₀/G₁ phase and decrease in S phase VSMCs.(3)Simvastatin increased protein level of PTEN and mevalonate, a metabolite of HMG-COA, reversed the effect of simvastatin on PTEN protein expression. CONCLUSION:Simvastatin may inhibit proliferation of VSMCs and retarded cell cycle in G₀/G₁ phase by increasing PTEN expression through inhibiting synthesis of mevalonate.     

Relationships of landscape,prey and agronomic variables to the abundance of generalist predators in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis>) fields

A two-year field study investigated the possible effects of grain sorghum (Sorghum bicolor [L.] Moench) and uncultivated areas on the abundance of generalist predators in commercially-managed cotton (Gossypium hirsutum L.) fields in Texas, USA. From 63 to 70 fields were sampled for pests and predators over nine consecutive weeks during early stages of cotton development. Additional data on agronomic practices and landscape composition at three spatial scales were also collected for each field. Stepwise regression analyses were used to determine the relationships of landscape, agronomic and prey variables to the abundance of generalist predators. Because the variables most closely linked to predator levels could vary over time, separate regressions were conducted for three time periods corresponding to stages of grain sorghum growth (half-bloom, hard-dough, maturity) in each year. Significant relationships between predator abundance and agricultural landscape composition appear in both years and in all three time periods, but the specific relationships of landscape variables to cotton predator levels differed between and within years. At maturity in 2001, predator levels rose as the amount of uncultivated land from 1.6 to 3.2 km distant and the perimeter shared with grain sorghum increased. During 2002, the area of grain sorghum (half-bloom) and uncultivated land (hard-dough) within 1.6 km of cotton fields were both positively related to predator numbers. Cotton planting dates and the abundance of cotton fleahoppers (Pseudatomoscelis seriatus [Reuter]) were also strongly linked to predator numbers during both years. Results suggest that the total amount of grain sorghum or uncultivated land in an area is more important than the presence of these habitats adjacent to cotton fields, and that landscape composition may sometimes be the most important factor in determining predator abundance.     

Influence of lanthanum nitrate on the expression of aquaporin 7 in the testis of rats

AIM: To find out whether different dosage of rare earth element-lanthanum can influence the expression of aquaporin 7(AQP 7) in the testis of rats. METHODS:Rats were fed with lanthanum nitrate[La(NO₃)₃]and killed 6 months later.Testes were then removed immediately to extract total RNA.Northern blot analysis is performed finally. RESULTS:0.1 mg/kg La(NO₃)₃ depressed the expression of AQP 7 in rat testis, while 20 mg/kg La(NO₃)₃ had no significant effect on it. CONCLUSION: AQP 7 expession is found in the rat testis; La(NO₃)₃ can depress the expression of AQP 7 in the rat testis.     

Ergebnisse der Leistungsprüfung von Kirschensorten auf wuchsreduzierenden Unterlagen in Ungarn

Zusammenfassung In Ungarn gibt es ein reges Interesse an intensivem Obstanbau. Der Erfolg dieses Anbaus hängt in sehr großem Maße von den Wechselwirkungen zwischen dem Standort, den Sorten-Unterlagen-Kombinationen und dem Anbauverfahren ab.Um die Wirkung wuchsreduzierender Kirschenunterlagen aus ausländischen Züchtungsinstituten unter ungarischen Klimaverhältnissen untersuchen zu können, wurde im Forschungsinstitut für Obst- und Zierpflanzenbau Budapest-Érd ein Vergleichsversuch durchgeführt. Der Versuch wurde mit Cerasus avium C. 2493, Weiroot 13, Weiroot 53, Weiroot 72, Weiroot 154, Weiroot 158, GiSelA 5 und P-HL-A-Unterlagen 1997 in der Versuchsanstalt des Forschungsinstituts für Obst- und Zierpflanzenbau Budapest-Érd aufgepflanzt. Als Kontrolle diente die Sämlingsunterlage Cerasus mahaleb Cema, deren Anteil im ungarischen Süßkirschenanbau bei 70–80% liegt. Die Unterlagen wurden mit drei Süßkirschensorten (Germersdorfi , Linda, Katalin) und mit einer Sauerkirschensorte (Piramis) veredelt.Nach der Wüchsigkeit bis zum Ende des 8. Standjahres konnten die Unterlagen in drei Gruppen eingeteilt werden: starkwüchsige (Cerasus mahaleb Cema, Cerasus avium C. 2493, Weiroot 13), mittelstarkwüchsige (Weiroot 158, Weiroot 154, P-HL-A) und schwachwüchsige Unterlagen (Weiroot 72, Weiroot 53, GiSelA 5). Die stärkste Neigung, Wurzelschosse zu treiben, zeigten Weiroot 13 und Weiroot 154.Während der Untersuchung der generativen Eigenschaften wurde beobachtet, dass es Unterschiede in der Blütezeit der Sorten-Unterlagen-Kombinationen gibt. Auf GiSelA 5 veredelte Sorten blühten 1 oder 2 Tage früher als die Kontrolle. Es gab nur geringe Unterschiede in der Reifezeit der Kombinationen. Den größten Ertrag hatte die Sorte Linda, gefolgt von Katalin, Germersdorfi 3 und Piramis. Der größte Fruchtdurchmesser wurde bei der Süßkirschensorte Germersdorfi 3 gefunden, der größte Anteil an Früchten größer als 26 mm bei den Bäumen auf Weiroot 72 (23%), der geringste Anteil großer Früchte bei den Bäumen auf GiSelA 5. Bei Piramis wurde der größte Fruchtdurchmesser auf Cerasus avium C. 2493 gemessen.     

Effects of corridors on home range sizes and interpatch movements of three small mammal species

Corridors are predicted to benefit populations in patchy habitats bypromoting movement, which should increase population densities, gene flow, andrecolonization of extinct patch populations. However, few investigators haveconsidered use of the total landscape, particularly the possibility ofinterpatch movement through matrix habitat, by small mammals. This studycompares home range sizes of 3 species of small mammals, the cotton mouse(Peromyscus gossypinus), old-field mouse (P.polionotus) and cotton rat (Sigmodon hispidus)between patches with and without corridors. The study site was in S. Carolina,USA. Corridor presence did not have astatistically significant influence on average home range size. Habitatspecialization and sex influenced the probability of an individual movingbetween 2 patches without corridors. The results of this study suggest thatsmall mammals may be more capable of interpatch movement without corridors thanis frequently assumed.This revised version was published online in May 2005 with corrections to the Cover Date.     

Quercetin regulates Fas expression and induces apoptosis in hepatocellular carcinoma HepG2 cells

AIM: To investigate the role of 1, 4, 5- trisphosphate inositol (IP3) and Fas gene expression in apoptosis of HepG2 cells induced by quercetin. METHODS: HepG2 cells were treated with quercetin at different concentrations (including 20, 40, 60, 80 μmol/ L) for 72 h and treated with 60 μmol/ L quercetin for 6 h, 12 h, 24 h, 48 h and 72 h. IP3, Fas mRNA, Fas protein and apoptosis rate were assayed by IP3 - ［3H］ Birtrak assay, RT-PCR, Western blotting and flow cytometry, respectively. RESULTS: When HepG2 cells were incubated with different concentrations of quercetin for 72 h, the IP3 content was lower than those in control. Fas mRNA expression, Fas protein expression and the apoptosis rate were higher than those in control. When HepG2 cells were incubated with quercetin for 6 h, 12 h, 24 h, 48 h, 72 h, the IP3 contents were lower than those in control incubated with 60 μmol/L quercetin for 12 h. Fas mRNA expression was higher than that in control incubated with 60 μmol/L quercetin for 12 h . Fas protein expression was higher than that in control. The apoptosis rate was significantly higher than that in control incubated with 60 μmol/L quercetin for 24 h (P<0.01). CONCLUSION: Quercetin induces apoptosis of HepG2 cells by reducing IP3 production and upregulating Fas gene expression.