Roseum Var Research Articles

Taxonomic Revision of Pseudognaphalium (Asteraceae, Gnaphalieae) from North America

The genus Pseudognaphalium Kirp., segregated from Gnaphalium L., is one of the largest genera of the tribe Gnaphalieae (Asteraceae) with about 60 species, most of them found in South, Central, and North America, but some species also occurring in Africa, Asia, Europe, and New Zealand. We present a taxonomic revision of Pseudognaphalium for North America accepting 36 species, mainly distributed in the Nearctic Region and the Mexican Transition Zone, and about one third of the species occurring in the Neotropical Region. The following taxa are newly synonymized: G. oaxacanum Greenm. with P. semiamplexicaule (DC.) Anderb., G. schraderi DC. with P. attenuatum (DC.) Anderb. var. sylvicola (McVaugh) Hinojosa & Villaseñor, P. altamiranum (Greenm.) Anderb. with P. roseum (Kunth) Anderb., and P. beneolens (Davidson) Anderb. with P. thermale (E. E. Nelson) G. L. Nesom. Lectotypes are newly designated for G. oblanceolatum Greenm., G. panniforme S. F. Blake, G. ramosissimum Nutt., G. roseum Kunth var. angustifolium Benth., G. roseum var. hololeucum Benth., and G. roseum var. sordescens Benth. Morphological descriptions are provided as well as taxonomic data on nomenclatural types, including synonymies, illustrations, distribution maps, distribution and habitat, additional material examined, distinguishing characters and taxonomic affinities for each taxon, biogeographical and ecological comments, and a key for their identification.

Phytochemical analysis, antimicrobial and antioxidant activities of Allium roseum var. odoratissimum (Desf.) Coss extracts

Polyphenolic extracts from fresh aerial parts (stalk, leaf, and flower) and bulbs of Allium roseum var. odoratissimum (Rosy garlic) harvested from Tunisian sandy soil were analyzed by high performance liquid chromatography (HPLC)-diode array detector (DAD) coupled with tandem mass spectrometry (MS), and tested for their antioxidant, antimicrobial, cytotoxic and antiviral activities.Leaves, stalks and flowers showed the highest total antioxidant capacity, scavenger activity against stable DPPH radical, and β-carotene bleaching capacity, with leaves and flowers extracts showing the highest total polyphenolic (84.39mg gallic acid equivalents/g plant organs dry residue) and total flavonoid [5.88mg (+)-catechin equivalents/g plant organs dry residue] contents, respectively. The metabolic profiles registered for the polyphenolic extracts revealed the presence of one hydroxycinnamic acid derivative, three flavones, and ten flavonols never detected before, with the only exception of kaempferol-3-O-glucuronide.Overall, all the tested polyphenolic extracts possessed high activity against Gram positive and Gram negative bacteria, and Candida spp. Strains, generally recognized as the most important pathogens affecting food dishes. Conversely, no toxicity on VERO cells line and no antiviral activity against Coxsakievirus B-3 and Herpes Simplex Virus type 2 were registered.This study gives a better insight into the potential healthy effects of Rosy garlic and the possibility of using it in food dishes to prevent contamination by the most common bacteria.

Chemical Composition and Biological Activities of Allium roseum L. var. grandiflorum Briq. Essential Oil.

Allium roseum L. (Alliaceae) endemic mediterranean specie was represented in the North Africa by 12 different taxa. In the present study, chemical composition, antiproliferative, antioxidant and antimicrobial activities of the essential oil extracted from A. roseum var. grandiflorum Briq. bulbs collected in the North of Tunisia were investigated. Chemical characterization has shown methyl methanethiosulfinate as major sulphurous compounds. A. roseum bulbs essential oil provides interesting antiproliferative activity against two human colonic adenocarcinoma HT29 and CACO2 cell lines in dose-dependent manner with a half-maximal inhibition (IC50) of 4.64 µg/mL and 8.22 µg/mL respectively. The antioxidant activity, as determined by FRAP assay, was 285 µmol equivalent Trolox/g of essential oil. The scavenging effect on DPPH radicals of essential oil was estimated as IC50 values at 156 µg/mL. The inhibition of superoxide anion production in a model of cancer cell lines was significant for both lines HT29 and CACO2 with IC50 of 20.25 µg/mL and 29.12 µg/mL respectively. Allium roseum essential oil exhibited antibacterial and antifungal activities with a high effectiveness against Candida albicans given by an MIC value of 0.019 mg/mL. This biological effect appears to be related mainly to the presence of organosulfur compounds.

여름어리표범나비(Mellicta ambigua (Menetries))의 생태적 특성에 관한 보고

ABSTRACT Recently the number of the butterflies, Mellicta ambigua, had been decreasing rapidly, and already disappeared at manyhabitat. In this studies, we investigated ecological environment of Mellicta ambigua for preparing of primary researchdata recovering habitat, and studied on bionomical characteristics. Two different habitat, Jindo and Inje, were selectedfor investigation of ecological environment. We investigated four times during 3-month, from June to August in 2012.In Jindo, we observed more than 100 butterflies and a lot of host plants, Melampyrum roseum var. japonicum. But only5 butterflies and only a few host plants, Veronicastrum sibiricum were observed in Inje. We could not observe the eggs,the larva and pupa on the host plants at all. For finding of bionomical characteritics, we reared butterflies at natural con-ditions. Collected 3-female butterflies from Jindo laid 465 eggs on the leaves of 3-host plants, Veronicastrum sibiricum.120 ~ 186 eggs per each female were laid in the shape of cluster. An egg was globular shape, 0.6 mm diameter and0.7 mm height. The egg periods were 9.96± 0.4 days after ovipositioning, and the hatchability was 95.% at natural con-dition. The larval periods were 4.1 ±0.6 days (1st instar), 2.11.0 days (2nd), 8.1± 0.7 days (3rd), 239.2± 10.9 days(4th), 12.3 ±1.3 days (5th), 17.1 1.1 days (6th), 10.5± 1.0 days (7th) each other. The larva of 4th instar overwinteredin the nest that had been made into the leaf of host plant with secreted thread as a group until early March next year.In the early March next year, overwintered larva went around their nest in search of host plants, and went to other hostplants, Veronica persica and Plantago asiatica, sometimes. The overwintered larva of Mellicta ambigua could grow upon two other host plants normally. In the following experiment, the butterflies of Mellicta ambigua laid eggs on theleaves of Plantago asiatica, but the 1st instar larva from eggs died all. The headwidth of each developmental larval stagewere 0.28 ±0.02 mm (1st), 0.45 ±0.02 mm (2nd), 0.58 0.02 mm (3rd), 0.75 0.03 mm (4th), 0.89± 0.05 mm (5th),1.23 ±0.06 mm (6th), 2.13± 0.11 mm (7th). The pupal ratio was 92.0%. The pupal period were 9.11.6 days, andthe emergence rate was 88.6%. As a result we determined that Mellicta ambigua can rear at natural conditions. Butindoor-rearing is considered to be difficult and not useful industrially, because they have long term larval stage and onlyone life cycle per an year.Key words : Mellicta ambigua, Habitat, Bionomical characteristics, Host plant, Rearing

Phytochemicals, antioxidant and antifungal activities of Allium roseum var. grandiflorum subvar. typicum Regel.

The chemical composition of essential oil hydrodistillized from Allium roseum var. grandiflorum subvar. typicum Regel. leaves was analyzed by GC and GC/MS. Nine extracts obtained from flowers, stems and leaves and bulbs and bulblets of A. roseum var. grandiflorum were tested for their total phenol, total flavonoid and total flavonol content. All these extracts and the essential oils from fresh stems, leaves and flowers were screened for their possible antioxidant and antifungal properties. The results showed that the hexadecanoic acid was detected as the major component of the leaf essential oil (75.9%). The ethyl acetate extract of stems and leaves had the highest antioxidant activity with a 50% inhibition concentration (IC50) of 0.35±0.01mg/mL of DPPH and 0.71±0.01mg/mL of ABTS+. All the extracts appeared to be able to inhibit most of the tested fungi. The essential oil of the leaves had an antifungal growth effect on Fusarium solani f. sp. cucurbitae and Botrytis cinerea (39.13 and 52.50%, respectively). This could be attributed to the presence of hexadecanoic acid, known for its strong antifungal activity. In conclusion, in addition to the health benefits of A. roseum, it can be used as an alternative pesticide in the control of plant disease and in the protection of agriculture products.

A New Essential Oil Chemotype of Allium Roseum Analyzed by an Apolar Column

This study deals with the chemical characterization of a medicinal and an aromatic plant of the Tunisian flora: Allium roseum var. odoratissimum, and aimed to identify new bioactive natural compounds in its flower essential oil. These compounds were extracted by hydrodistillation and were analyzed by GC and GC/MS, using an apolar column. The most important compounds characterized were organo-sulphurous (46%), including methyl 2-propenyl trisulfide, di-2-propenyl trisulfide, di-1-propenyl disulfide, di-2-propenyl disulfide, dimethyl trisulfide, methyl 2-propenyl disulfide, and di-1-propenyl trisulfide, found as 10.75, 9.07, 5.81, 4.98, 3.90, 3.30, and 2.53%, respectively. Moreover, heneicosane and pentacosane were identified for the first time at relatively high rates (8.18 and 4.49%, respectively) in the Allium roseum essential oil. This essential oil composition exhibited newly identified sulphurous compounds at relatively high rates (46.53%) when compared with what was found while using polar column.

Phenolic constituents, antioxidant and antimicrobial activities of rosy garlic (Allium roseum var. odoratissimum)

The methanol extracts of leaves, flowers, stalks and bulbs of the North African endemic Allium roseum var. odoratissimum were analyzed for their phenolic profiles and screened for their antioxidant and antibacterial activities. Colourimetric analysis revealed that the highest levels of total phenols content (TPC) and total flavonoids content (TFC) were found in the flowers and leaves. The use of HPLC-PDA-MS allowed the identification of kaempferol 3,7-di-O-rhamnoside, kaempferol-3-Glucuronide, kaempferol-3-O-glucoside, kaempferol-3-O-beta-d-glucoside-7-O-alpha-l-rhamnoside, luteoline and apigenine, while four components remained unidentified. The flowers and leaves were found to possess the highest antioxidant activity with the exception in metal chelating ability. Antibacterial assay showed that Enterococcus feacium was the most susceptible bacterial strain and the stalk extract had the most effect in the inactivation of Staphylococcus aureus, Enterococcus feacium, Bacillus subtilis and Escherichia coli. Conclusively, this study allows a clear chemical differentiation between A. roseum var. odoratissimum and the other Allium species.

PHYTOCHEMICAL SCREENING AND ANTIBACTERIAL PROPERTIES OF ALLIUM ROSEUM L., A WILD EDIBLE SPECIES IN NORTH AFRICA

ABSTRACT Allium roseum L. var. odoratissimum, a North African endemic species, grows in the Southeast of Tunisia and is used as a vegetable, spice or herbal remedy in traditional medicine. This study deals with the phytochemical analyses and antimicrobial activity screening of A. roseum leaves. Aqueous extracts (maceration, digestion, decoction and infusion) and organic extracts (petroleum ether, dichloromethane, methanol and ethanol) were screened for their phytochemical antibacterial activity. Phytochemical screening of A. roseum showed the presence of antimicrobial active compounds such as saponins, tannins, flavonoids, coumarins, steroids, cardiotonic glycosides, free quinone and iridoids. The dichloromethane, petroleum ether and ethanolic extracts of A. roseum exhibited a wide spectrum of antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Escherichia coli and Pseudomonas aeruginosa. Such results may establish a good support to the use of this plant in herbal medicine and a base for the development of new drugs and phytomedicine. PRACTICAL APPLICATIONS Allium roseum var. odoratissimum (Desf.) Coss is widely used as a vegetable, spice and herbal remedy. Besides its culinary use, A. roseum is also used in folk medicine for the treatment of headaches, rheumatism, respiratory tract infection and low appetite. In this article, we validate the use of this species through the chemical constituents (saponins, tannins, flavonoids, coumarins, steroids, cardiotonic glycosides, free quinones and iridoids), which are responsible for the pharmacological properties mentioned earlier, particularly the antibacterial activity. For example, A. roseum exhibits a wide spectrum of antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Escherichia coli and Pseudomonas aeruginosa.

Essential oil composition and antibacterial activity of different extracts of Allium roseum L., a North African endemic species

This study deals with the valorisation of medicinal and aromatic plants of the Tunisian flora, in order to find new bioactive natural products. The essential oil constituents from the flowers of Allium roseum var. odoratissimum, a North African endemic species growing in the south-east of Tunisia, were extracted by hydrodistillation and analysed by GC–MS. The most important compounds were sulphurous compounds (2,4-dimethylthiophene, 2-propenyl methyl disulfide, 1-propenyl methyl disulfide, dimethyl trisulfide, and 3-methyl-thiopropionaldehyde or methional). After an exhaustive literature review dealing with other varieties of the same species, it seems that the variety odoratissimum is the only taxon characterized by trisulfide and methional contents. Methional is of particular importance because it is found at high concentration (17%). The antibacterial activity of seven extracts was evaluated by the diffusion method and by determining the inhibition zone. All extracts exhibited an antibacterial activity at different levels against strains reported as the causal agents of food-borne diseases. Results suggest the potential use of the plant as condiment and preservative in the food industry. La présente étude porte sur les possibilités de valorisation d'une plante aromatique et médicinale de la flore tunisienne dans le but de mettre au point de nouveaux produits bioactifs. Il s'agit d'Allium roseum var. odoratissimum, qui est une espèce endémique nord-africaine, très commune en Tunisie méridionale. Les constituants des huiles essentielles des fleurs de cette plante, extraites par hydrodistillation, ont été analysés par GC–MS. Les principaux constituants de ces huiles étaient des dérivés soufrés (2,4-diméthylthiophène, 2-propénylméthyle disulfide, 1-propénylméthyle disulfide, diméthyl trisulfide et 3-méthyl-thiopropionaldéhyde ou méthional). Ces résultats, analysés à la lumière des données bibliographiques à propos d'autres variétés de la même espèce, permettent de dire que la variété odoratissimum est le seul taxon qui est caractérisé par la présence des trisulfides et du méthional. Ce dernier a été détecté à une forte concentration (17%). L'activité antibactérienne des sept extraits testés a été étudiée par la méthode de diffusion et de détermination de la zone d'inhibition. Tous ces extraits ont montré une activité antibactérienne plus ou moins importante vis-à-vis des souches signalées. Ces résultats suggèrent la possibilité d'utiliser cette plante comme condiment et agent de conservation dans l'industrie alimentaire.

First report of Fusarium arthrosporioides on medusahead (Taeniatherum caput‐medusae) and preliminary tests for host‐specificity

Medusahead ( Taeniatherum caput-medusae ssp. asperum ) is an economically important weed in the USA. Foreign exploration to search for natural enemies of this weed in its native range resulted in finding the fungus, Fusarium arthrosporioides (syn. F. roseum var. arthrosporioides ), isolated from the collar of medusahead in August, 2001 in Greece. Identification was made using both morphological and molecular criteria. The sequence of the internal transcribed spacer (ITS) region that was amplified by PCR using ITS1-F and ITS4-A primers, was similar to F. arthrosporioides sequences published in GenBank. Colonies were grown at 20 ° C on half-strength potato dextrose agar (PDA) (Difco Laboratories, Detroit, MI, USA). Colonies on agar were pink on the margin and red in the middle of the upper side with an abundant floccose aerial mycelium which was initially white and turned brown with time. Cultured on synthetischer nahrstoffarmet aghar (SNA), macroconidia were formed in pale orange sporodochia with three to five septa and a distinct footshaped base. Microconidia were oval, 0–1-septate. Fusarium arthrosporioides , a relatively common soilborne fungus, has never been reported on the genus Taeniatherum . In the past it has been studied as a potential biological control agent of Orobanche (Amsellem et al ., 1999). Two-week-old medusahead seedlings were transplanted into autoclaved soil artificially infested with 1 g of inoculum (1-month-old sterile wheat seeds inoculated with a 5 mm square side of a PDA-grown colony) for 10 g of soil. After 11 days, inhibition of normal root development with concomitant leaf discoloration was observed. After 3 weeks, re-isolation of the pathogen from the roots and collar was successful. Utilizing the same inoculation methods, preliminary tests of the medusahead isolates for host-range specificity on wheat, barley, oat and some grasses ( Elymus repens , Hordeum murinum , Pennisetum clandestinum , Phacelia tanacetifolia ) clearly demonstrated its nonspecificity. Eleven days after inoculation 60% of the barley plants showed symptoms of infection; after 3 days wheat exhibited severe dwarfing. Dry weight comparisons of both inoculated barley and wheat to controls were significant. To our knowledge, this is the first report of F. arthrosporioides attacking T. caput-medusae . Based on our results, F. arthrosporioides will not be considered for further studies on biocontrol of medusahead.

Ultrastructure of in vivo interactions of the antagonist bacteria Bacillus cereus X16 and B. thuringiensis 55T with Fusarium roseum var. sambucinum, the casual agent of potato dry rot.

The interaction of Fusarium roseum var. sambucinum, the causal agent of potato dry rot, with two antagonistic bacteria, Bacillus cereus X16 and B. thuringiensis 55T, was studied on wounded potato tubers using light and electron microscopy. Application of B. cereus X16 or B. thuringiensis 55T to potato wounds before challenge with the pathogen suppressed dry rot and restricted fungal growth in plant tissues to the first few cell layers beneath the site of inoculation. Both bacterial antagonists penetrated into potato tissues and established themselves through intercellular and intracellular proliferation. The extent of Fusarium colonization was appreciably reduced in the bacterized tubers, and most fungal cells in these tubers were severely damaged, with appreciable morphological and structural changes. In potato tubers bacterized by B. thuringiensis 55T, Fusarium invasion of the host tissues did not stimulate structural host reactions, and direct parasitism, which operates by degradation of the fungal cell walls and disintegration of the fungal cytoplasm, seemed to play a key role in the antagonism against Fusarium hyphae. In potato tubers inoculated with B. cereus X16 and challenged with the pathogen, on the other hand, a set of defense reactions, were triggered, including modifications of the primary cell walls and the occlusion of some cells and vascular tissues with different types of electron-opaque materials. Fungal hyphae in the vicinity of these barriers, apparently containing higher than usual levels of phenol-like compounds, usually showed advanced stages of disorganization, suggesting the existence of a fungitoxic environment. The results presented here show that the two antagonistic bacilli use different biocontrol strategies to suppress Fusarium dry rot development.

Biological Control of the Potato Tubers Dry Rot Caused by Fusarium roseum var. sambucinum under Greenhouse, Field and Storage Conditions using Bacillus spp. Isolates

AbstractSelected isolates of Bacillus spp. from salty soils were evaluated for their ability to suppress a dry rot disease on potato tubers caused by Fusarium roseum var. sambucinum. Greenhouse trials undertaken in pots demonstrated that bacterial antagonists stimulated the emergence of potato tubers. Evaluation of yield parameters showed the efficiency of isolates I32 of B. licheniformis and X16 of B. cereus to reduce disease severity. Field experiments showed that the isolate X16 of B. cereus seems to be the most effective to control Fusarium rot on seed tubers and increase yield parameters. The seed tuber colonization by bacteria increased until 61 days after planting with a rate significantly higher for B. cereus X16 (2 ×103 CFU/cm2). After 75 days, it decreased for all the treatments applied. Moreover, traditional and cold storage assays run during 6 and 8 months respectively, showed that dry rot incidence was significantly lower in potato boxes treated with each antagonist alone or by the mixture (X16 + B. thuringiensis var. galleriae 55T and Trichoderma viride + 55T) as compared with pathogen inoculated control boxes and to those treated with the fungicide carbendazim.

ULTRASTRUCTURE AND CYTOCHEMISTRY OF IN VITRO INTERACTIONS OF THE ANTAGONISTIC BACTERIA BACILLUS CEREUS X16 AND B. THURINGIENSIS 55T WITH FUSARIUM ROSEUM VAR. SAMBUCINUM

SUMMARY The present studies were undertaken to investigate the interaction of the bacterial antagonists Bacillus cereus X16 and B. thuringiensis 55T with Fusarium roseum var. sambucinum, the causal agent of potato dry rot. On wounded potato tubers, both bacilli effectively suppressed the development of Fusarium dry rot. Nevertheless, confrontation of the fungal pathogen with the antagonists on nutrient agar revealed that B. cereus X16, induced a strong visible inhibition zone but B. thuringiensis 55T did not. Light microscopy of the interaction regions after confrontation with B. cereus X16 on nutrient agar generally showed apparently intact fungal cells with densely stained protoplasm, indicating that the inhibition was due to stasis rather than toxicity. By contrast, in presence of B. thuringiensis, Fusarium cells appeared markedly damaged, with partial to complete cell wall disintegration and disorganization and generally complete loss of protoplasm. These observations suggest that, contrary to our expectations, antibiotic and chitinolytic activities of B. thuringiensis 55T may be highly significant in the parasitism of the pathogen. Confrontation in liquid medium revealed that both bacteria completely inhibited the germination of Fusarium macroconidia and resulted in their destruction. This suggests that, to produce their fungitoxic and hydrolytic effects, the two bacteria should make intimate contact with Fusarium cells.

Variation in fruit‐ and seed set among and within inflorescences of Melampyrum roseum var. japonicum (Scrophulariaceae)

Abstract Variations in fruit set and seed set among and within inflorescences of the annual herb, Melampyrum roseum var. japonicum, were studied. Under natural conditions, although the mean fruit set was slightly different among inflorescences, the mean seedset was not significantly different among inflorescences within the plants. In constrast, within the inflorescences, the flowers located at a lower position of the inflorescence and which opened earlier showed higher fruit set than those at a higher position and which opened later. However, the seed set of matured capsules were not significantly different from each other, regardless of the position of flowers within the inflorescences. Patterns of the fruit‐ and seed set under open pollination indicated that variation in seed reproduction of M. roseum is due to variation in fruit production. The results of clipping experiments of flowers revealed that there was no functional limitation in seed production among flowers located at various positions within the inflorescence. It seemed that the variation in the fruit set within the inflorescences of M. roseum was not attributable to ‘architectural effects’. Reduction of the number of flowers within the inflorescences resulted in an increase of fruit set and seed weight, indicating that the flowers in an inflorescence compete for resources. This phenomenon supports the ‘resource competition hypothesis’, and variation in fruit set within the inflorescence is attributable to competition among flowers within the inflorescence for limited resources. Consequently, it was concluded that, under natural conditions, the early blooming flowers located at lower positions of the inflorescences obtain more resources and produce more fruits than the late blooming flowers located at higher positions in M. roseum.

EVALUATION OF BACTERIAL ISOLATES FROM SALTY SOILS AND BACILLUS THURINGIENSIS STRAINS FOR THE BIOCONTROL OF FUSARIUM DRY ROT OF POTATO TUBERS

SUMMARY A total of 83 spore-forming bacteria belonging to the genus Bacillus was isolated from Tunisian salty soils. These isolates as well as five additional strains of Bacillus thuringiensis, previously selected for their efficiency against insects, were tested in vitro and in vivo against Fusarium roseum var. sambucinum, the causal agent of dry rot of potato tubers. Results of the in vitro dual culture screening revealed that more than 50% of Bacillus spp. isolated from salty soils inhibited the growth of the pathogen in vitro. By contrast, all five B. thuringiensis strains failed to inhibit the growth of the pathogen in vitro. On wounded potato tubers, the most effective isolates obtained from salty soils were X7, X9, X16, I32 and G7, with a percentage of dry rot reduction ranging from 66 to 89%. These effective Bacillus isolates were identified as belonging to one of the species B. cereus (X9, X16 and G7), B. lentimorbus (X7) or B. licheniformis (I32). Although ineffective in vitro, B. thuringiensis strains inhibited dry rot development in vivo, with percentage inhibition scores ranging from 41 to 52%. While Bacillus isolates selected from salty soils best inhibited dry rot development when applied as young cultures (24 h), B. thuringiensis strains generally performed better as older cultures (48-72 h). The cell-filtrates of Bacillus spp. were unable to inhibit the growth of Fusarium. By contrast, volatiles liberated by the antagonists seem to contribute to the inhibition of the pathogen. The two isolates X16 of B. cereus and I32 of B. licheniformis as well as all 3 tested strains of B. thuringiensis (1T, 10T and 55T) were able to degrade colloidal chitin. Our experiments with the chromogenic chito-oligosaccharides indicated also that B. cereus (X16) and B. thuringiensis (55T) are able to produce N-acetyl-β-D-glucosaminidases, chitobiosidases and endochitinases. The isolate X16 of B. cereus consistently showed a chitinase activity 2 to 3 fold higher than that of strain 55T of B. thuringiensis. The hydrolysis of

Selection for Root and Crown Rot Resistance in Alfalfa1

Root and orown rot cause extensive damage to alfalfa (Medicago sativa). In this study, Fusorium solani followed by F. oxysporum, F. roseum, and F. tricinctum were most frequently isolated.Two techniques of inoculation, with one isolate of F. roseum var. acuminatum, were used for screening alfalfa for Fusarium root rot resistance. Both techniques were effective in producing a high percentage of infection. The application technique used on 3‐month‐old plants gave 5.9% resistant plants in the cultivar ‘Europa.’ Only 3.2% resistant plants were found when the bareroot‐soak technique was applied on 3‐week‐old seedlings. Resistance was evaluated by measuring the vertical discoloration in the split taproot. Plants with less than a 5mm spread of internal browning from the wound site were saved and intercrossed.The populations developed through each technique were established in the field at three locations in the spring of 1977 and rated for root rot in the fall of 1978. The two populations selected for resistance showed consistently less root rot than the unselected one although differences were not statistically significant.In a greenhouse study we were able to detect significant variation for root rot infection among as well as within polyerossed progenies of the selected genotypes suggesting that resistant genes for this disease are present in alfalfa. Narrow‐sense heritability was estimated at 22%. Some specific crosses were made between resistant (R) and susceptible (S) plants. The cross S ✕ S showed almost twice as much root rot infection as the cross R ✕ R. R ✕ S was better than expected based on mid value of R ✕ R and S ✕ S.Based on the results of this study, we believe progress is possible toward developing a crown and root rot resistant alfalfa.

Phenylalanine ammonia lyase activity and fungitoxic metabolites produced by potato cultivars in response to Fusarium tuber rot

The specific activity of phenylalanine ammonia lyase (PAL), glycoalkaloid and sesquiterpene accumulation were measured in potato tubers ( Solanum tuberosum L.) at 48, 96, and 168 h following wounding or inoculation with a spore suspension of the dry rot pathogen Fusarium roseum var. sambucinum. Activity of PAL was higher in inoculated than in wounded tissues and remained higher up to 168 h after inoculation in both resistant and susceptible cultivars. PAL activities in inoculated tissues of four clones of divergent genotype varied threefold but very high resistance shown by the breeding clone BR6316-7 was not related to its PAL activity. Challenge with the nonpathogen Fusarium reseum resulted in less stimulation of PAL activity than did inoculation with the virulent Fusarium roseum var. sambucinum or with the relatively weak pathogen Alternaria solani. Steroid glycoalkaloid accumulation was repressed in inoculated tissues of both resistant and susceptible clones compared to wounded controls. This repression was least, however, in the highly resistant clone. The terpenoids, rishitin, phytuberin, and a compound tentatively identified as lubimin, were detected in inoculated tissues of both resistant and susceptible cultivars 48 h after inoculation. Total accumulation after 168 h was least in the highly resistant clone and greatest in the most susceptible clone. The three factors measured appear to be involved in a generalized response to the dry rot pathogen for both resistant and susceptible cultivars. Moderate resistance as shown by the cultivar Pioneer may be related to an intensification of this generalized response following inoculation, but very high resistance involves other mechanisms.

NUMERICAL TAXONOMY OF SPECIES IN ALLIUM SUBGENUS MOLIUM

SUMMARYNumerical methods have been used to study the relationships between twenty‐two operational taxonomic units (O.T.U.'s) in Allium subgenus Molium Koch (Wendelbo). Data were obtained by investigating fifty‐five morphological and cytological characters and thirty‐one chemical characters, the latter being volatiles, mainly sulphides, derived from bulb tissue. The CLASP programme was used to produce a number of phenetic classifications firstly by hierarchical cluster analyses, the results being presented as dendrograms showing percentage similarities of O.T.U.'s and as minimum spanning trees (M.S.T.), and, secondly, by principal co‐ordinates analyses, the results being presented as vector plots. Three sets of classifications have been produced; the first employing the morphological and cytological characters on all twenty‐two O.T.U.'s, the second using chemical data on only fifteen O.T.U.'s and the third using all characters.The O.T.U.'s have been divided into six major groups as follows: (a) A. cernuum; (b) A. triquetrum and A. paradoxum; (c) A. oreophilum and A. oreophilum cv. Zwanenburg; (d) A. erdelii; (e) A. zebdanense, A. roseum, A. roseum var. bulbiferum, A. subvillosum, A. neapolitanum, two subspecies of A. trifoliatum and A. subhirsutum; (f) A. moly, A. scorzonerifolium, A. geyeri, A. unifolium, A. fibrillum, A. acuminatum and A. dichlamydeum. These groups and their subgroups are discussed in the light of biosystematic studies, particularly the ability of taxa to cross with others. The phenetic classifications produced are also compared with the previous taxonomic arrangements of the subgenus.

Saccharase Activity of Fusarium roseum var. graminearum and F. roseum var. culmorum in Soil Culture

Journal of PhytopathologyVolume 78, Issue 3 p. 227-231 Saccharase Activity of Fusarium roseum var. graminearum and F. roseum var. culmorum in Soil Culture Á. Szécsi, Corresponding Author Á. Szécsi Research Institute for Plant Protection, BudapestDr. Á. Szécsi, Research Institute for Plant Protection, Budapest, II. Herman Ottó 15 (Hungary).Search for more papers by this author Á. Szécsi, Corresponding Author Á. Szécsi Research Institute for Plant Protection, BudapestDr. Á. Szécsi, Research Institute for Plant Protection, Budapest, II. Herman Ottó 15 (Hungary).Search for more papers by this author First published: November 1973 https://doi.org/10.1111/j.1439-0434.1973.tb04172.xCitations: 1 With 3 tables AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume78, Issue3November 1973Pages 227-231 RelatedInformation

Reproduction and Survival of Confused Flour Beetles Exposed to Metabolites Produced by Fusarium roseum var. graminearum12

Reproduction and Survival of Confused Flour Beetles Exposed to Metabolites Produced by Fusarium roseum var. graminearum12