利用大葱幼叶进行组织培养微繁的研究

以大葱幼叶为外植体，成功地建立了大葱的无性繁殖系和高效的培养体系。在ＭＳ＋２，４－Ｄｌｍｇ／Ｌ＋ＫＴ０．５ｍｇ／Ｌ＋ＢＡｌｍｇ／Ｌ的培养基上，愈伤组织的诱导率为８９．９％，在ＭＳ＋２，４－Ｄ０．８８ｍｇ／Ｌ＋ＢＡ１．７３ｍｇ／Ｌ的培养基上达到最大芽诱导率１３．２１％，平均每块愈伤组织生芽５．１４个，在天激素的培养基上最易生根。２５０天内的繁殖系数可达３７８７倍。     

甜菜基因型的筛选及胚性细胞系建立的研究

通过以甜菜未成熟胚为外植体诱导愈伤组织，再将产生的愈伤组织转移至分化培养基（ＭＳＢ培养基附加１．０ｍｇ／Ｌ６－ＢＡ，３％蔗糖，８％琼脂）进行分化力测试实验，筛选出两个再生能力强的基因型－８９３０，ＧＤ２。通过挑选淡黄色或灰白色，呈颗粒状的愈组织继代培养，经调节培养基的ＩＡＡ和ＮＡＡ的浓度，得到再生能力强的胚性愈伤组织，建立了胚性细胞无性系。     

脱毒大蒜花原始体培养增殖技术的研究

以黑龙江省阿城脱毒紫皮种蒜为试材，应用植物组织培养技术，探讨利用花原始体进行培养增殖的技术，结果表明：以ＭＳ为基本培养基，诱导花原始体愈伤组织形成的最佳激素组合为：２，４－Ｄ０．０５ｍｇ／Ｌ＋ＢＡ１．０ｍｇ／Ｌ，转移至ＮＡＡ０．０５ｍｇ／Ｌ＋ＢＡ３．０ｍｇ／Ｌ组合的培养基后，每块花原始体愈伤组织平均分化９．２个幼芽，经切割，继代于ＮＡＡ０．０５ｍｇ／Ｌ＋ＢＡ３．０ｍｇ／Ｌ组合的培养基后又可增殖２９．３个幼芽，其繁殖系数为３．１８４８。因此脱毒种蒜ｌ个总苞内的全部花原始体经愈伤组织诱导，幼苗分化，增殖３个阶段１５０天的培养，可得１３０９．５株试管苗，并且经幼苗根尖染色体压片、镜检，未发现有任何染色体变异。     

荔枝组织培养中胚状体产生的类型及分析

以荔枝２０—３０ｄ龄幼胚为外植体诱导产生愈伤组织，并筛选建立了幼胚胚性愈伤组织系。胚性愈伤组织在附加２，４－Ｄ的ＭＳ培养基上诱导胚状体分化，在附加ＮＡＡ和ＩＢＡ的培养基中促进胚状体的发育和成熟。在体外胚胎发生过程中，形成大量各种类型的胚状体，其中出现不少异常胚；胚性愈伤组织继代培养过程中存在大量的染色体变异，这可能是产生异常胚的重要原因之一。     

荔枝胚性愈伤组织的诱导和保持

以荔枝绿沙，兰竹，东刘一号三个品种的４－７周幼胚为外植体，培养胚性愈伤组织的发生，结果表明，以２，４－Ｄ２ｍｇ／Ｌ和ＢＡ０．５－１ｍｇ／Ｌ配合使用，可使以上三个品种的胚性愈伤组织诱地率分别为绿沙２３－２７％，兰竹２８．６－３０５．％，东刘一号２９－３３．７％。采用有激素和无激素培养基交替继代可以长期保持兰竹，东刘一呈的胚性愈伤组织。     

西瓜高效组织培养再生体系的初步研究

以不同基因型材料的西瓜品种为试材,用ＭＳ、Ｍｉｌｌｅｒ、Ｎ６与不同激素配比的培养基,初步建立了西瓜离体组培再生体系。结果表明,不同浓度的ＭＳ培养基均可长出无菌苗,但随着ＭＳ培养基营养元素浓度的增大,无菌苗生长发育受到延迟和抑制作用加强,其中以 １／２ ＭＳ＋ ０．５～２ ｍｇ／Ｌ ＢＡ＋ ０． ｍｇ／Ｌ ＮＡＡ长出的无菌苗作外植体诱导愈伤组织最快,改良的 ＭＳ（ＭＳＩ＋ ２ ｍｇ／Ｌ ＢＡ＋０．１ｍｇ／ＬＮＡＡ）是西瓜愈伤组织诱导的最适培养基,改良的ＭＳ（ＭＳＩ＋２ｍｇ／ＬＢＡ＋０．１ｍｇ／ＬＮＡＡ＋５ ｍｇ／ＬＡｇＮＯ３）是外植体诱导分化不定芽的最适培养基,离子束等物理因子处理愈伤组织发现对诱导分化不定芽具有刺激和促进作用。     

石竹花芽发生与内源多胺含量的关系

以石竹叶片为外植体,诱导愈伤组织、营养芽、花芽的培养基分别为ＭＳ＋ＺＴ２．５ｍｇ／Ｌ＋２,４－Ｄ０．３ｍｇ／Ｌ;ＭＳ＋ＺＴ１ｍｇ／Ｌ＋ＢＡ２ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ;ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．３ｍｇ／Ｌ。在石竹离体叶花芽形成过程中,内源多胺含量呈不同的变化趋势,腐胺、亚精胺含量上升,而二丙胺、精胺含量下降,表明多胺与石竹离体叶花芽分化有明显的内在联系。     

猕猴档体细胞胚状体导及植株再生

叶片及叶柄在ＮＭ＋２，４－Ｄ０．５－２．０＋３％蔗糖及ＰＨ５．８的培养基上诱导产生胚性俞伤组织，并获得了分化胚状体及幼株的能力。胚性愈伤组织在ＮＭ＋ＺＴ０．５－２．０＋３％蔗糖培养基中分化胚状体，胚状体进一步发育并萌发成幼株。ＮＭ基本培养基适合壮苗培养。     

‘艾西丝’南瓜子叶的离体培养

用‘艾西丝’南瓜子叶作外植体离体培养,成功地建立了一套子叶高频率诱导再生芽的程序。在ＭＳ＋ＢＡ ４．０ｍｇ／Ｌ＋ＩＡＡ０．４ｍｇ／Ｌ的培养基上,以４ｄ苗龄子叶基部切块为外植体,其不定芽的诱导率最高,达５０％,在ＭＳ＋ＢＡ０．２５－０．５ｍｇ／Ｌ的培养基上继代,增殖培养效果较好,在无激素的１／２ＭＳ培养基上最易生根。     

苹果离体叶片培养直接体细胞胚胎发生研究

在ＭＳ＋ＢＡ１０ｍｇ／Ｌ＋ＮＡＡ５０ｍｇ／Ｌ＋２，４＿Ｄ０＼＾５ｍｇ／Ｌ＋蔗糖２０ｇ／Ｌ的固体培养基上，苹果品种嗄拉试管苗叶片经７天暗培养产生胚性细胞。将具有胚性细胞的叶片转入ＭＳ＋ＢＡ１０ｍｇ／Ｌ＋蔗糖２０ｇ／Ｌ的培养基上暗培养４０天，６５％的叶片直接发生体细胞胚，体细胞胚在同种培养基上萌发，长成小植株。     

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.