Transfer of a male-sterility-inducing cytoplasm from onion to leek ( Allium ampeloprasum)

Two interspecific triploid (AAC) hybrids (84/1-94 and 99/1-94) from crosses between onion [ Allium cepa (2 n=2 x=16, CC)] and leek [ A. ampeloprasum (2 n=4 x=32, AAAA)] were backcrossed to leek in order to transfer a male-sterility-inducing cytoplasm from onion that would enable the production of hybrid leek. GISH evaluations of meiosis in the interspecific hybrids revealed irregularities due to univalent onion chromosomes producing micronuclei from onion chromatin, whereas the pairing of the two sets of leek chromosomes was nearly normal. Attempts to use colchicine to double the chromosome number of the hybrids failed. Backcrosses of 84/1-94 to leek as the pollen parent were not successful. The first backcross of 99/1-94 to tetraploid leek produced 11 BC(1) plants with chromosome numbers between 38 and 41. Identification of parental chromosomes by GISH showed that all eight onion chromosomes and 30-33 leek chromosomes were transmitted to the backcross progenies due to unreduced egg cells. Onion chromosomes were eliminated during the second backcross. Southern hybridization confirmed the transfer of the T-cytoplasm like source of CMS from onion to the BC(2) progenies. After the third backcross to leek, 158 plants were obtained with varying numbers of onion chromosomes and some intergenomic recombinant chromosomes. Alloplasmic leek plants without onion chromatin were selected for further characterization of male sterility and quality traits.     

应用生物技术脱除大蒜病毒的研究

大蒜普遍感染病毒,是影响产量的关键因素.应用生物技术对大蒜进行脱毒研究,获得了脱毒再生植株和脱毒蒜.结果表明,选用带一片叶原基的茎端作外殖体比较适宜,既能保证成活率,又有较好的脱毒效果;筛选出适宜茎端生长的培养基MS附加KT0.5mg/l,NAA0.5mg/l,成苗率70%以上;筛选出低浓度盐的生根培养基,生根率100%;采用电镜定量检测法进行病毒测定,再生株脱毒率达到53.8%.已获得脱毒的二代两瓣大蒜,其直径和重量已经超过正常的商品蒜.     

Oviposition and feeding preference of Acrolepiopsis assectella Zell. (Lep., Acrolepiidae)

Abstract:  The leek moth, Acrolepiopsis assectella (Zell.), is a recently discovered exotic species in eastern Ontario and western Quebec. This Allium spp. (Asparagales, Alliaceae) specialist can cause up to 40% crop damage. A no-choice experiment was used to determine the relationship between oviposition behaviour and larval survival of the leek moth as the phylogenetic distance from the preferred host Allium ampeloprasum var. porrum L. increased. Results indicate that oviposition preference and larval survival of the leek moth declined as the phylogenetic distance from the preferred host increased. These results support the conclusion that the leek moth is a specialist feeder on closely related Allium spp. although the strength of this preference may decline as the motivation to oviposit increases. This may indicate that the leek moth is able to use closely related novel hosts as temporary refuges if the preferred host plant is unavailable.     

The C-S lyases of higher plants. Purification and characterization of homogeneous alliin lyase of leek (Allium porrum)

The characteristic odors of freshly macerated tissue of Allium species such as garlic and onion are due to the action of the enzyme alliin lyase (EC 4.4.1.4) on endogenous S-alkyl-I-cysteine sulfoxides which are present as secondary amino acids yielding volatile sulfur-containing products. Purification and characterization of the alliin lyase of leek ( Allium porrum L.) has been carried out for comparison with the analogous enzymes previously characterized from garlic and onion. The purification involved homogenization, followed by ammonium sulfate fractionation, elution from an hydroxylapatite column, concentration of the active fractions and passage through a concanavalin A-Sepharose 4B affinity column. The purified enzyme was found to be a glycoprotein with a pH optimum for activity of 8.0. Sodium dodecylsulfate-urea polyacrylamide gel electrophoresis gels of the homogeneous leek enzyme showed it consisted of 1 subunit with a molecular weight of 48000. By gel filtration, 2 stable forms of the native enzyme with molecular weights of 386000 and 580000 were found.     

Dormancy in Garlic (Allium sativum L.) cv. Rosado Paraguayo I. Levels of Growth Substances in "Seed Cloves" under Storage

The period of dormancy in "seed cloves" of garlic (Allium sativumL.) under storage was determined by measuring the growth ofthe "first foliar leaf" and its sprouting capacity. The endogenouscontents of growth inhibitors and gibberellins were also measuredby bioassays. Dormancy of garlic bulbs can be characterizedby lack of gibberellin and a presence of moderate contents ofgrowth inhibitors. (Received October 26, 1982; Accepted August 25, 1983)     

Developmental Regulation of Lectin and Alliinase Synthesis in Garlic Bulbs and Leaves

Using a combination of northern blot analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a detailed study was made of the temporal and spatial regulation of garlic (Allium sativum L.) lectins and alliinase throughout the life cycle of the plant. The two bulb-specific lectins (ASAI and ASAII), which are the most predominant bulb proteins, accumulate exclusively in the developing garlic cloves and progressively disappear when the old clove is consumed by the plant. On the basis of these observations, ASAI and ASAII can be regarded as typical vegetative storage proteins. The leaf-specific lectin (ASAL), on the contrary, is specifically synthesized in young leaves and remains present until withering. Because ASAL is only a minor protein, it probably fulfills a specific function in the plant. Unlike the lectins, alliinase is present in large quantities in bulbs as well as in leaves. Moreover, intact alliinase mRNAs are present in both tissues as long as they contain living cells. The latter observation is in good agreement with the possible involvement of alliinase in the plant's defense against pathogens and/or predators.     

Occurrence and taxonomic significance of cysteine sulphoxides in the genus Allium L. (Alliaceae)

Methiin was present in all investigated samples. In the genus Allium, methiin-dominated species (rarely used by man) were common, but the occurrence of the other cysteine sulphoxides was variable and was largely correlated with use as spices or vegetables. Two major chemical types (named according to the species where they occur) could be distinguished, and at least two more may be recognized. Isoalliin dominates in the widely used "onion-type", which includes chive (A. schoenoprasum) and top onion (A.xproliferum). Pearl onion and leek (A. ampeloprasum) have higher relative amounts of methiin and propiin, respectively. Alliin dominates in the widely used "garlic-type", which includes wild leek (A. obliquum) and sand leek (A. scorodoprasum). Alliin and isoalliin rarely co-dominate, being only found in the cultivated Chinese leek (A. tuberosum). A triple mix of almost equal amounts of methiin, alliin and isoalliin is present in ramson (A. ursinum). General trends in the three evolutionary lines of the genus Allium were apparent. In the first lineage, high amounts of methiin were more frequent, and propiin, although being a minor component in all three evolutionary lines, was present in the highest amounts. Most of the species in the second line showed only traces of cysteine sulphoxides. In the third line, the "onion-type" dominates, the "garlic type" is characteristic for subgenus Allium, and co-dominating alliin and isoalliin also occur. Generally, the total cysteine sulphoxide amount increased, and the complexity of cysteine sulphoxide patterns decreased in the transition from the first to the third evolutionary line.     

Isolation and characterization of lectins and lectin-alliinase complexes from bulbs of garlic (Allium sativum) and ramsons (Allium ursinum)

A procedure developed to separate the homodimeric and heterodimeric mannose-binding lectins from bulbs of garlic (Allium sativum L.) and ramsons (Allium ursinum L.) also enabled the isolation of stable lectin-alliinase complexes. Characterization of the individual lectins indicated that, in spite of their different molecular structure, the homomeric and heteromeric lectins resemble each other reasonably well with respect to their agglutination properties and carbohydrate-binding specificity. However, a detailed analysis of the lectin-alliinase complexes from garlic and ramsons bulbs demonstrated that only the heterodimeric lectins are capable of binding to the glycan chains of the alliinase molecules (EC 4.4.1.4). Moreover, it appears that only a subpopulation of the alliinase molecules is involved in the formation of lectin-alliinase complexes and that the complexed alliinase contains more glycan chains than the free enzyme. Finally, some arguments are given that the lectin-alliinase complexes do not occur in vivo but are formed in vitro after homogenization of the tissue. This revised version was published online in November 2006 with corrections to the Cover Date.     

Differential organ infection studies, potyvirus elimination, and field performance of virus-free garlic plants produced by tissue culture

Presence of potyvirus in single garlic (Allium sativum L.) cloves from the same bulb, and in five single leaves excised from commercial field-grown individual plants was studied using ELISA. It was found that the viruses were not present in all organs of the same plant, since some cloves of the same bulb were infected with potyvirus but some others were potyvirus-free. Analyzed leaves from a given plant also exhibited irregular distribution of potyvirus. This study also aimed to obtain potyvirus-free plants from two commercial garlic cultivars (Taiwan and Chileno) using cloves subjected to thermotherapy, chemotherapy or meristematic dissection followed by in vitro culture. Thermotherapy (sequential treatment at 32°C for a week, 36°C for 2 weeks, and 38°C for 3 weeks) was found to affect survival of explants and 36.5% cloves from Taiwan and 26.8% from Chileno cultivars were recovered after the treatment. ELISA tests showed that 63% of the cloves of Taiwan that survived the treatment and 70.9% of Chileno explants were potyvirus-negative. Regarding chemotherapy (205 μM Ribavirin solution), the explants (cloves) survived, but only an average of 27.0–34.8% were negative for the presence of potyvirus. When meristematic dissection was applied, an average of 41.7% explants of Taiwan and 34.2% of Chileno survived the treatment, and approximately 64% of these explants from both cultivars were potyvirus-negative. Potyvirus-free garlic plants grown in field conditions showed longer stems with a major fresh and dry weight per bulb, and also exhibited a higher yield than non-treated plants.     

Compounds from Allium species with cytotoxic and antimicrobial activity

Garlic (Allium sativum L.) is a bulb-shaped plant belonging to the Allium genus which also includes onions (Allium cepa L.), leek (Allium ampeloprasum L. var. porrum Gay), shallot (Allium ascalonicum L), scallion (A. fistulosum L.) and chives (Allium schoenoprasum L.). The biological activity of garlic has been known since ancient times. Babylonians, Egyptians, Phoenicians, Greeks and Romans used garlic as a remedy for intestinal disorders, respiratory infections, skin diseases, bacterial infections, worms, wounds and tumors. In particular, before the discovery of antibiotics, garlic has been used against amoebic dysentery and epidemic diseases such as typhus, cholera, diphtheria, and tuberculosis. To date, more than 3,000 publications scientifically supported the use of garlic in the ethno-medicine. But what makes garlic and Allium species effective against cancer? The effect of garlic may arise from its antibacterial properties or from its ability to block formation on cancer-causing substances, half the activation of cancer causing substances, enhance DNA repair, reduce cell proliferation or induce cell death. Epidemiological studies have found that an increase of consumptions of Allium spp. reduce the risk of prostate and gastric cancers and this has been mainly related to two main classes of compounds: the apolar sulphur compounds and the polar saponins. These latter compounds, compared to the more studied thiosulphinates, have the advantages of not being pungent and more stable during cooking. Recently, there has been increasing scientific attention given to such compounds. In this paper, the literature about the major volatile and non-volatile organic compounds of garlic and other Allium plants has been reviewed. Particular attention is given to the compounds possessing antibacterial and cytotoxic activity in garlic and in the other Allium species and their mechanism of action.     

The closely related homomeric and heterodimeric mannose-binding lectins from garlic are encoded by one-domain and two-domain lectin genes, respectively.

Lectin cDNA clones for two different lectins from garlic (Allium sativum L.) bulbs, ASAI and ASAII (ASA, Allium sativum agglutinin), were isolated and characterized. The first lectin, ASAI, is a heterodimer composed of two different subunits of 11.5 kDa and 12.5 kDa. It is translated from an mRNA of 1400 nucleotides encoding a polypeptide of 306 amino acids with two very similar domains. N-terminal sequencing of the two polypeptides of the mature lectin confirmed that both subunits are derived from the same precursor and that each corresponds to one of the two domains in the sequence. In contrast to ASAI, the second garlic lectin, ASAII, is a homodimer of two identical 12-kDa subunits. It is translated from an mRNA of approximately 800 nucleotides encoding a polypeptide of 154 amino acids. Interestingly, the coding region of the ASAII cDNA clones is almost identical to that of the second domain of the ASAI cDNA clones.     

Sequential estimation of nuclear DNA and silver staining of nucleoli in plant cells

A method for sequential estimation of nuclear DNA and silver staining of nucleoli in plant cells is described. Feulgen staining is done first and nuclear DNA estimated by absorption cytophotometry. Following this, the slides are stained with AgNO3. The method has been used to study the process of nucleolar fusion in garlic (Allium sativum L.) meristem root tip cells. It was found that during interphase nucleoli rarely fused, thus most fusion must have occurred before the G1 phase of the cell cycle.     

Antithrombotic and anticancer effects of garlic-derived sulfur compounds: a review

Garlic (Allium sativum L.) has a long history as being a food having a unique taste and odor along with some medicinal qualities. Modern scientific research has revealed that the wide variety of dietary and medicinal functions of garlic can be attributed to the sulfur compounds present in or generated from garlic. Although garlic produces more than 20 kinds of sulfide compounds from a few sulfur-containing amino acids, their functions are different from one another; e.g., allicin, methyl allyl trisulfide, and diallyl trisulfide have antibacterial, antithrombotic, and anticancer activities, respectively. The present paper reviews the physiological functions of garlic in the limited study fields of its antithrombotic and anticancer effects. Before describing these effects, however, we will discuss briefly some characteristics of garlic as a plant and some modes of absorption of orally-administered sulfur compounds from garlic.     

Development of a cyclic somatic embryogenesis regeneration system for leek (Allium ampeloprasum L.) using zygotic embryos

Summary In leek (Allium ampeloprasum L.) a cyclic system of somatic embryogenesis was developed. Somatic embryos used for cyclic embryogenesis were able to develop the same type of embryogenic callus as zygotic embryos in the primary cycle. For the first time a comparison of the efficiencies of both expiants was made. Ten families were investigated for somatic embryogenesis. There was a genetic relationship with respect to somatic embryo production between the reciprocal crosses. From each family one genotype was selected for investigating cyclic somatic embryogenesis. Different levels of somatic embryo production were found between the expiants of zygotic and somatic embryos. The two best genotypes, 92.001-03 and 92.002-33 produced twice as many somatic embryos as the overall average. On average, 56% of the somatic embryos finally developed into greenhouse plantlets.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzyladenine - MS medium Murashige and skoog (1962) basal medium     

Efficacy of plant extracts against stored-products fungi

The fungistatic activity of six aqueous extracts of plants were tested against Aspergillus candidus, Aspergillus niger, Penicillium sp. and Fusarium culmorum. The plants were, chamomile (Anthemis nobilis L.), cinnamon (Cinnamomum verum J. Presl.), French lavender (Lavandula stoechas L.), garlic (Allium sativum L.), malva (Malva sylvestris L.) and peppermint (Mentha piperita L.). The more concentrated extracts of chamomile and malva inhibited totally the growth of the tested fungi with malva the most effective one.     

Stable genetic transformation of garlic plants using particle bombardment

The improvement of garlic plants (Allium sativum L.) via biotechnological approaches is currently limited by the lack of an applicable direct gene transfer system. In this paper, we present the development of a genetic transformation system using particle bombardment for gene delivery and immature clove-derived callus as the gene target. Plasmid DNA (pBI221.23), containing the selectable "hpt" gene for hygromycin resistance and the reporter "gus" gene, was delivered into callus tissue that had been previously treated with aurintricarboxylic acid as an endogenous nuclease inhibitor. The transformed calli were selected using hygromycin B, regenerated, and analysed at the molecular level using DNA hybridization, transgenome rescue and histochemical beta-glucuronidase assay. The results indicated that biolistic transformation can lead to the transfer, expression and stable integration of a DNA fragment into garlic chromosomal DNA. The relative simplicity of this system is a good recommendation for its future use in the production of genetically modified garlic plants.     

Allexivirus transmitted by eriophyid mites in garlic plants

Viruses in garlic plants (Allium sativum L.) have accumulated and evolved over generations, resulting in serious consequences for the garlic trade around the world. These viral epidemics are also known to be caused by aphids and eriophyid mites (Aceria tulipae) carrying Potyviruses, Carlaviruses, and Allexiviruses. However, little is known about viral epidemics in garlic plants caused by eriophyid mites. Therefore, this study investigated the infection of garlic plants with Allexiviruses by eriophyid mites. When healthy garlic plants were cocultured with eriophyid mites, the leaves of the garlic plants developed yellow mosaic strips and became distorted. In extracts from the eriophyid mites, Allexiviruses were observed using immunosorbent electron microscopy (ISEM). From an immunoblot analysis, coat proteins against an Allexivirus garlic-virus antiserum were clearly identified in purified extracts from collected viral-infected garlic plants, eriophyid mites, and garlic plants infected by eriophyid mites. A new strain of GarV-B was isolated and named GarV-B Korea isolate 1 (GarV-B1). The ORF1 and ORF2 in GarV-B1 contained a typical viral helicase, RNA-directed RNA polymerase (RdRp), and triple gene block protein (TGBp) for viral movement between cells. The newly identified GarV-B1 was phylogenetically grouped with GarV-C and GarV-X in the Allexivirus genus. All the results in this study demonstrated that eriophyid mites are a transmitter insect species for Allexiviruses.     

Staphylococcal growth and enterotoxins (A—D) and thermonuclease synthesis in the presence of dehydrated garlic

E. GONZÁLEZ-FANDOS, M.L. GARCÍA-LÓPEZ, M.L. SIERRA AND A. OTERO. 1994. The inhibition of Staphylococcus aureus growth and enterotoxin and thermonuclease production by various concentrations of garlic ( Allium sativum ) was studied in BHI broth. The growth of Staph. aureus was inhibited by dehydrated garlic at levels of 1.5% (w/v) and over. Enterotoxins A, B and C₁ were only detectable in broth containing < 1% of garlic while enterotoxin D was produced at a level of 2%. Garlic also inhibited thermonuclease (TNAse) production, complete inhibition being observed at levels ≥ 1.5%. TNAse was not always detected when enterotoxin was present.     

大蒜中期染色体内的核糖核蛋白物质

研究了大蒜（Ａｌｌｉｕｍ ｓａｔｉｖｕｍ Ｌ．）中期染色体的超微结构和ＲＮＰ物质。常规染色表明,大部分染色体内部有低电子密度区,有的染色体中低电子密度区域较大而似孔洞。银染结果也证明了有大小不等的孔洞存在。Ｂｅｒｎｈａｒｄ 染色显示,在染色体周边和染色体内部都有ＲＮＰ分布。用ＮａＯＨ 处理证明了Ｂｅｒｎｈａｒｄ 染色法所显示的深染区确实含有ＲＮＡ。ＲＮＰ量的多少与ＥＤＴＡ 的分化时间呈负相关     

Garlic extract attenuates time-dependent changes in the reactivity of isolated aorta in streptozotocin-diabetic rats

In the present study, the effect of aqueous garlic extract (Allium sativum; 100 mg/Kg/day; i.p.) on the vascular reactivity of streptozotocin (STZ)-diabetic rats was investigated. Vascular reactivity of isolated aortic rings was assessed by measuring phenylephrine-induced contractile and acetylcholine-induced relaxation responses. The results showed that aortas prepared from 8-week, but not 4-week, STZ-diabetic rats exhibited significantly increased contractile responses, which were partially attenuated by garlic extract treatment. The maximum vasorelaxant response of pre-contracted aortic rings exposed to acetylcholine also significantly decreased in 8-week STZ-diabetic animals which was attenuated to some extent by extract treatment. It is concluded that long-term administration of garlic extract (i.p.) can attenuate various functional alterations induced by STZ-diabetes in the vascular system of an insulin-dependent model of uncontrolled diabetes, and this may suggest a potential approach to future therapeutic strategies.