Regeneration and characterisation of Cucumis melo L. (+) Cucumis anguria L. var. longipes (Hook. fil.) Meeuse somatic hybrids

Cotyledon protoplasts of an albino Cucumis melo L. ‘Cantaloup Charentais’ somaclonal variant were electrofused with protoplasts of the wild species Cucumis anguria L. var. longipes (Hook. fil.) Meeuse. Selection of putative somatic hybrids was based on competence of the albino melon to grow and regenerate shoots together with the ability of the wild species to synthesise chlorophyll. The ITS region of C. anguria ribosomal DNA was sequenced to design species-specific primers, which allowed us to distinguish between parental lines and fusion products by PCR amplification. By using this method, all the organogenic lines characterised proved to be somatic hybrids. Three of sixteen selected lines produced shoots with albino and green sectors. Eleven lines remained green but shoots developed abnormally and did not produce roots in vitro. Two hybrid lines regenerated normal shoots but with a limited ability to produce roots in vitro and in vivo. Applicability of molecular characterisation to optimise the quick recovery of fusion products is discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

In vitro culture of Cucumis sativus L.

Summary The ability to regenerate plants from leaf explants has been tested for three highly inbred cucumber lines (B, G, S), their reciprocal hybrids, F₂ and BC₁ generations. The lines differed from each other in their regenerating ability, which was expressed by the percentage of explants regenerating embryoidal callus and mean number of plantlets per plant. Thus, the lines could be classified as frequently (B), intermediately (G) or occasionally regenerating ones (S). There were no reciprocal cross differences in the regeneration. It was found that the intermediately and intensively regenerating lines contain two pairs of dominant genes responsible for plant regeneration, characterized by complementary and probably additive interaction. The frequently regenerating line differed from the intermediately regenerating in the effect of one gene. It is supposed that the above-mentioned genes belong to three different loci. The ability to regenerate plants from leaf expiants had high heritability.     

Secondary plasmodesmata formation in the minor-vein phloem of Cucumis melo L. and Cucurbita pepo L.

Numerous branched plasmodesmata (pd) are present between bundle-sheath cells (BSCs) and specialized companion cells known as intermediary cells (ICs) in the minor-vein phloem of melon (Cucumis melo L.) and squash (Cucurbita pepo L.). These pd were found to be secondary, i.e., they form across existing walls. Sink, sink-source transition, and source tissues were sampled from developing and mature leaves. In sink tissue, IC precursors divide to produce the two to four ICs and associated sieve elements which are present by the time of the sink-source transition. Plasmodesmata along the interface between the IC precursor and adjacent BSCs in sink tissue are unbranched and few in number. Before the leaf tissue undergoes the sink-source transition, the number of pd channels (individual branches of pd) becomes more numerous. This increase in number of pd channels occurs at least in part and perhaps entirely by branching, resulting in more channels on the IC-side than on the BSC-side. In melon there is a 12-fold increase in the number of pd channels within the IC-side of the interface and a corresponding 9-fold increase in pd channels within the BSC-side. Thus, secondary pd form by the time of the sink-source transition and may be involved in phloem loading and photoassimilate export. The system described is well-defined and amenable to experimental manipulation: secondary pd form in large numbers, at a particular interface, over a short period of time, and in a highly predictable manner.Abbreviations BSC bundle-sheath cell - DAP days after planting - IC intermediary cell - LPI leaf plastochron index - pd plasmodesmata - PI plastochron interval We thank Edith Haritatos, Rich Medville, Esther Gowan, and Nancy Dussault for expert technical assistance. This research was supported by an NSF/DOE/USDA Cornell Plant Science Center fellowship (G.M.V.), Natural Sciences and Engineering Research Council Grant GP0138401 and Université de Montréal, Fonds internes de recherche (D.U.B.), and NSF grant IBN-9419703 (R.T.).     

In vitro Antimicrobial Activity of Cucumis L. and Momordica L. against Human Pathogens

Doklady Biological Sciences - Plants are the rich source of compounds having antimicrobial properties against human pathogens. The present study has been carried out to evaluate the antimicrobial...     

Reproduction and cytogenetic characterization of interspecific hybrids derived from Cucumis hystrix Chakr. x Cucumis sativus L

Interspecific hybrids between Cucumis hystrix Chakr. (2n = 2 x = 24) and Cucumis sativus L. (2n = 2 x = 14) were produced by means of F(1) (2n = 19) embryo rescue and subsequent chromosome doubling. The hybridity was confirmed by genomic in situ hybridization (GISH) and chromosome analysis. The amphidiploid (2n = 38) was self-pollinated and backcrossed to cucumber resulting in lines with improved crossability to C. sativus. Examination of shape, stainability, and germination rate of pollen grains and yield as a function of mature fruit set per ten pollinated flowers indicated a tendency for increased fertility in BC(1)S(1) progeny when compared to F(1) and amphidiploid offspring. Cytogenetic characterization of F(1) and amphidiploid progeny was performed. Generally normal meioses produced viable pollen grains, and fertilization resulted in partial fertility restoration in amphidiploid progeny. Chromosome anomalies such as "frying-pan trivalent", chromosome lagging and spindle mis-orientation were also observed. In most of the PMCs of the F(1) diploid hybrid progeny, 19 univalents were observed at diakinesis and MI. In the amphidiploid, more than 90% of the configurations at MI consisted of the predicted 19 bivalents and less than 5% contained multivalents [trivalents (2.3%) + quadrivalents (0.3%)], suggesting the presence of preferential pairing, and a distinctive parental genome as well. The chiasmata observed between homoeologous chromosomes further demonstrated the introgression of the C. hystrix genome into that of C. sativus.     

黄瓜藤的化学成分研究

从丽江产黄瓜藤甲醇提取物的氯仿部位分离得到9个化合物,经理化和波谱分析鉴定为α-菠甾醇(1)、α-菠甾醇-3-O-β-D-葡萄糖苷(2)、β-谷甾醇(β-sitosterol,3)、豆甾-7-烯-3-O-β-D-葡萄糖苷(4)、22-亚甲基-9,19-环羊毛甾烷-3β-醇(5)、(2S,3S,4R,10E)-2-(2′,3′-二羟基二十四烷酰氨基)-10-十八烯-1,3,4-三醇(6)、(2S,3S,4R,10E)-2-[(2′R)-2-羟基二十四烷酰氨基]-10-十八烯-1,3,4-三醇(7)、(2S,3S,4R,10E)-1-(β-D-葡萄糖苷)-2-[(2′R)-2-羟基二十四烷酰氨基]-10-十八烯-1,3,4-三醇(8)、大豆脑苷(9),除化合物3外,其它化合物均为首次从该植物中分离得到.     

Distribution and immunolocalization of stachyose synthase in Cucumis melo L.

Indirect evidence for the site of stachyose biosynthesis has been provided by determining the occurrence and distribution of stachyose, raffinose and galactinol, the donor of the galactosyl moiety for stachyose synthesis, in Cucumis melo L. cv. Ranjadew. Studies of enzyme activities for the synthesis of these sugars and their distribution in different plant organs and isolates has led to the conclusion that stachyose is synthesized mainly in mature leaves and seeds. Nevertheless, stachyose-synthase activity varied with leaf age, the developmental stage of a plant, the growing season and the plant cultivar used. No stachyose or stachyose-synthase activity could be detected in isolated mesophyll protoplasts and chloroplasts, whereas both were found in a minor-vein-enriched fraction isolated from mature leaves. The conclusion that stachyose biosynthesis is associated with minor veins was confirmed by immunolocalization of the enzyme. Positive specific immunoreactivity of stachyose synthase with polyclonal anti-stachyose-synthase antibodies, labeled with protein A-gold, was detected in intermediary cells of leaf minor veins. The implication of this local synthesis of the main transport sugar for phloem loading in mature leaves of Cucumis melo is discussed.Abbreviation RUBPCase ribulose-1,5-bisphosphate carboxylase This work was supported by Deutsche Forschungsgemeinschaft. The excellent assistance of Ms. B. Müller in preparing the samples for electron microscopy is gratefully acknowledged. The authors thank Professor H.J. Schneider-Poetsch for anti-RuBPCase antibodies.     

黄瓜的冷害及耐冷性

随着蔬菜反季节栽培面积的不断扩大,如何提高黄瓜(Cucumis sativus L.)耐冷性已成为选育新品种的研究重点.系统地综述近几年黄瓜耐冷性的鉴定、获得途径、冷害机理以及遗传和分子遗传学等方面的研究,以促进对黄瓜冷害机制的研究,加速耐冷品种的培育.耐冷性鉴定时要从耐冷指数、低温发芽能力、MDA(丙二醛)含量和电解质渗漏率等几个方面综合鉴定.耐冷性的获得途径主要有冷驯化、激素处理、热激处理和培育耐低温品种,最重要的途径是耐冷品种选育.黄瓜冷害机理包括细胞膜的流动性降低及透性增加,光合作用被抑制,根系吸收减弱,可溶性糖含量减少,淀粉粒积累增加,微管的稳定性受到破坏等.黄瓜低温发芽能力由非加性基因决定,而幼苗时期主要由加性基因控制.黄瓜耐冷的分子遗传学研究进展缓慢,目前已克隆出在低温锻炼中特异表达的功能未知的基因CCRl8.今后还应研究黄瓜低温胁迫时的信号转导系统,以进一步揭示黄瓜的冷害机理;利用野生资源的抗逆性状,拓宽栽培黄瓜的遗传基础,选育适于保护地栽培的耐低温品种.     

黄瓜的冷害及耐冷性

随着蔬菜反季节栽培面积的不断扩大,如何提高黄瓜(Cucumis sativus L.)耐冷性已成为选育新品种的研究重点。系统地综述近几年黄瓜耐冷性的鉴定、获得途径、冷害机理以及遗传和分子遗传学等方面的研究,以促进对黄瓜冷害机制的研究, 加速耐冷品种的培育。耐冷性鉴定时要从耐冷指数、低温发芽能力、MDA (丙二醛)含量和电解质渗漏率等几个方面综合鉴定。耐冷性的获得途径主要有冷驯化、激素处理、热激处理和培育耐低温品种,最重要的途径是耐冷品种选育。黄瓜冷害机理包括细胞膜的流动性降低及透性增加,光合作用被抑制,根系吸收减弱,可溶性糖含量减少,淀粉粒积累增加,微管的稳定性受到破坏等。黄瓜低温发芽能力由非加性基因决定,而幼苗时期主要由加性基因控制。黄瓜 耐冷的分子遗传学研究进展缓慢,目前已克隆出在低温锻炼中特异表达的功能未知的基因CCR18。今后还应研究黄瓜低温胁迫时的信号转导系统,以进一步揭示黄瓜的冷害机理;利用野生资源的抗逆性状,拓宽栽培黄瓜的遗传基础,选育适于保护地栽培的耐低温品种。     

Photocontrol of hypocotyl elongation in light-grown Cucumis sativus L.

An interaction is demonstrated between the effects of phytochrome and cryptochrome (the specific blue-light photoreceptor) in the inhibition of hypocotyl elongation of light-grown cucumber (Cucumis sativus L.) cv. Ridge Greenline seedlings. At certain fluence rates of blue light the total inhibition response is greater than the sum of the separate responses to each photoreceptor. The threshold for response to blue light is reduced at least 30-fold by additional red-light irradiation. The synergistic effect is demonstrated for two different fluence rates of red light. Synergism is mediated by phytochrome in both the cotyledons and the hypocotyl.Abbreviations and symbols BL blue light - FR far-red light - Pfr far-red-absorbing form of phytochrome - R red light - photostationary state of phytochrome - _c calculated      

黄瓜果肉色的遗传分析

以1份西双版纳黄瓜和2份普通黄瓜自交系为试验材料配制2个杂交组合,并构建4世代群体(P1、P2、F1、F2).分别采用目测分级、色差仪测定a值和b值以及HPLC方法测定β-胡萝卜素含量等4个指标,研究黄瓜果肉色性状的遗传规律.结果表明:2个杂交组合F2群体的果肉色相关指标呈单峰偏态或双峰分布,表现为主基因+多基因的数量遗传特征.多世代联合分析表明,黄瓜果肉色遗传基本符合两对主基因+多基因模型.两组合8个果肉色相关指标最优模型的F2群体主基因遗传率较高,为76.0%～99.3%,多基因遗传率较低,为0～23.7%.对黄瓜橙黄果肉色的选择应在分离早期世代进行.     

微生物菌肥对设施黄瓜生长、产量及品质的影响

为探讨微生物菌肥在设施栽培黄瓜上的应用效果,以水果黄瓜为实验材料,设定施用"宁盾"A液(T1)、施用"宁盾"B液(T2)、同时施用"宁盾"A液与"宁盾"B液(T3)、对照(CK)4个处理,结果表明"宁盾"能够促进黄瓜植株生长、提高叶绿素含量和产量、改善果实营养品质;同时提高根际土壤蔗糖酶、脲酶的活性,增加根际土壤中氮、磷、钾等大量元素的含量,其中"宁盾"A液与B液配合使用效果最佳。     

Nitrate transport across the tonoplast of Cucumis sativus L. root cells

Nitrate transport across the tonoplast has been studied using vacuole membranes isolated from cucumber roots grown in nitrate. The addition of NO3- ions into the tonoplast with ATP-generated transmembrane proton gradient caused the dissipation of delta pH, indicating the NO3(-)-induced proton efflux from vesicles. NO3(-)-dependent H+ efflux was almost insensitive to the transmembrane electrical potential difference, suggesting the presence of an electroneutral NO3-/H+ antiporter in the tonoplast. Apart from saturation kinetics, with respect to nitrate ions, NO3(-)-linked H+ efflux from the tonoplast of cucumber roots showed other characteristics expected of substrate-specific transporters. Experiments employing protein modifying reagents (NEM, pCMBS, PGO and SITS) indicated that a crucial role in the activity of tonoplast nitrate/proton antiporter is played by lysine residues (strong inhibition of NO3-/H+ antiport by SITS). None of the ion-channel inhibitors (NIF, ZnSO4 and TEA-Cl) used in the experiments had a direct effect on the nitrate transport into tonoplast membranes. On the other hand, every protein reagent, as well as NIF and ZnSO4, significantly affected the ATP-dependent proton transport in vesicles. Only TEA-Cl, the potassium channel blocker, had no effect on the vacuolar proton pumping activity.     

微生物菌肥对设施黄瓜生长、产量及品质的影响

为探讨微生物菌肥在设施栽培黄瓜上的应用效果,以水果黄瓜为实验材料,设定施用"宁盾"A液(T1)、施用"宁盾"B液(T2)、同时施用"宁盾"A液与"宁盾"B液(T3)、对照(CK)4个处理,结果表明"宁盾"能够促进黄瓜植株生长、提高叶绿素含量和产量、改善果实营养品质;同时提高根际土壤蔗糖酶、脲酶的活性,增加根际土壤中氮、磷、钾等大量元素的含量,其中"宁盾"A液与B液配合使用效果最佳。     

Galactosyl-sucrose metabolism and UDP-galactose pyrophosphorylase from Cucumis melo L. fruit

In muskmelon ( Cucumis melo L.), sink tissues receive stachyose, raffinose and sucrose through phloem translocation of carbohydrates that are formed as products of leaf photosynthesis. Melon fruits accumulate sucrose massively during the final stages of maturation. This sucrose is derived partially from the catabolism of raffinose saccharides. Rapid galactose metabolism is required, because liberation of free galactose is the first step in the metabolic utilization of the raffinose sugars. The current study demonstrates that the enzyme UDP-glucose-hexose-1-P uridylyltransferase (EC 2.7.7.12), the central enzyme in the classical Lelior pathway, is not the central enzyme in galactose metabolism in muskmelon fruit. Rather, a broad substrate specificity UDP-galactose pyrophosphorylase (PPase) serves the same functional role. This enzyme accepts either UDP-galactose or UDP-glucose as a substrate and is different from a UDP-glucose PPase with more strict substrate specificity for UDP-glucose that is also present in melon tissue. UDP-galactose PPase was purified 113-fold from melon tissue and was shown to be a 54 kDa (size exclusion chromatography) to 68 kDa (SDS-PAGE) protein that is enzymatically active as a monomer. We also present evidence that the enzyme likely accepts UDP-galactose and UDP-glucose at the same catalytic site. Polyclonal antibodies prepared against this protein reacted with numerous other antigens in melon extracts, apparently as a result of the presence of common antigenic epitopes.     

甜瓜属植物抗根结线虫种质资源研究进展

根结线虫是危害甜瓜属栽培作物的重要病害之一,长期以来人们围绕抗根结线虫种质资源进行了多方面研究,本文就甜瓜属植物抗根结线虫种质资源鉴定、创新,抗根结线虫砧木,根结线虫抗性机理以及遗传规律研究进展进行了综述.     

Photocontrol of hypocotyl elongation in light-grown Cucumis sativus L.

The control by phytochrome of hypocotyl elongation of light-grown Cucumis sativus L. after a white-light period was examined. The farred-absorbing form of phytochrome inhibits hypocotyl elongation. The response to phytochrome photostationary state () is not linear; all values of from 0.004 to 0.13 promote growth maximally, in the range of values of from 0.13 to 0.22 there is a linear growth response, between values of of 0.22 and 0.35 there is again no differential effect, and for values above 0.35 there is a strong (near linear) effect of on elongation. A kinetic examination of events following the white-light period shows that the major recovery from the photoperiod requires 8.5 h of darkness. End-of-day far-red treatment produces a very different response pattern, with a minor growth stimulation within 28 min of treatment followed by a major effect after 80 to 90 min. Three hours after far-red treatment there is a transient decline in growth rate which persists for about 2 h. Over the whole time course there is a great stimulation of growth rate compared with the controls. A similar growth-rate pattern also occurs if the end-of-day is 0.48, although the magnitude of the growth stimulation is less. Two components are affected by end-of-day , namely the time at which growth recovers and the subsequent growth rate. In the long term, the latter accounts for most of the differences in elongation growth. The dark recovery when only the hypocotyl is irradiated requires 4 h, but end-of-day far-red treatment reduces this to about 1.5 h. The persistence of the far-red-absorbing form of phytochrome for many hours in darkness in these light-grown plants is also demonstrated.Abbreviations and symbols D darkness - FR far-red light - Pfr far-red-absorbing form of phytochrome - R red light - WL white light (from fluorescent lamps) - photostationary state of phytochrome - _c calculated      

Callus Induction and Protoplast Isolation from Tissues of Cucumis Sativus L. and C. Melo L. Seedlings

Hypocotyls, cotyledons and true leaves of in vitro seedlings of 10 cucumber and melon genotypes resistant to downy and powdery mildew were cultured on several combinations of initiation and multiplication media to produce callus and subsequently cell suspensions as suitable sources for isolation and culture of protoplasts. Cotyledons of both species were shown to be the most responsive to variation in culture media. However, calli and cell suspensions derived from hypocotyls generally provided higher number of protoplasts by treatment with several enzymatic solutions. The protoplasts formed new cell walls after 12 h of culture in liquid culture medium and first cell division was observed 2 d later with more frequent divisions after one week of culture. This revised version was published online in July 2006 with corrections to the Cover Date.     

Ultrastructural Changes in Chloroplasts of Cucumis sativus L. and Secale cereale L. during Low-Temperature Hardening

Russian Journal of Plant Physiology - Chloroplast ultrastructural changes were investigated in chilling-sensitive (cucumber, Cucumis sativus L.) and cold-tolerant (winter rye, Secale cereale L.)...     

不同类型西双版纳黄瓜果实成熟期营养成分分析

西双版纳黄瓜（Cucumis sativus L. var. xishuangbannanesis Qi et Yuan）是我国特有的黄瓜变种,老瓜果肉橙黄是区别于普通黄瓜的主要特征之一。本文以不同类型版纳黄瓜为研究对象,分析果实成熟期主要营养成分及其变化规律。结果显示,18份版纳黄瓜老瓜的平均β-胡萝卜素含量为106.58mg/kgDW,叶黄素0.48mg/kgDW,Vc4.96 mg/100g,可溶性糖1.97%,Ca173.21mg/kg,Fe1.28mg/kg,Mg121.89mg/kg,P339.67mg/kg,Zn1.47mg/kg。不同种质的β胡萝卜素含量差异较大,变异范围1.34~261.55mg/kgDW,变异系数67.68%。随着果实成熟期的延长,版纳黄瓜的β-胡萝卜素和α-胡萝卜素含量呈显著增高的趋势,而叶黄素含量明显下降。在果实成熟期未检测到番茄红素。β-胡萝卜素积累是版纳黄瓜果肉颜色形成的主要原因。