Phylogenetic analysis of chloroplast DNA matK gene and ITS of nrDNA sequences reveals polyphyly of the genus Sonchus and new relationships among the subtribe Sonchinae (Asteraceae: Cichorieae)

Phylogenetic relationships among genera of the subtribes Sonchinae (11 genera and ca. 130 species) and Dendroseridinae (2 genera and 12 species) sensu Bremer were assessed with ITS and matK gene sequences. The Sonchinae is strongly supported as paraphyletic, and subtribal rank of Dendroseridinae is poorly supported. This study re-delimits Sonchinae, which now includes 14 genera and ca. 146 species. Two genera, Reichardia and Launaea, diverge first, followed by a major radiation of the remaining species, including Dendroseris and Thamnoseris. The monotypic Aetheorhiza is more closely related to Sonchus than to Launaea. Sonchus is highly polyphyletic, occurring across nearly all clades of the trees. It is highly probable that several Pacific and Atlantic island endemics evolved within the Sonchus group. Polyploidization processes appear to have played an important role in evolutionary differentiation and speciation in Sonchus, especially in subgenus Sonchus. This study identifies 10 major clades within the Sonchinae, and emphasizes the need to re-delimit and re-circumscribe Sonchus and the Sonchinae.     

裂叶苣荬菜的研究

本文对裂叶苣荬菜(Sonchus arvensis L)进行了初步研究。考察了它的植物生态特征和分布环境,预试了化学成分并进行了临床病例观察。为裂叶苣荬菜以其本名作为治疗肝炎的草药入药提供了可靠的依据。     

苣苣菜的营养成分测定

分析测定了山东中部野生苣苣菜的营养成分 ,结果表明 ,其主要营养成分含量与常见蔬菜相当或较高 ,并含有 1 8种氨基酸 ,其中包括 8种必需氨基酸 ,EAA/TAA =3 7.3 % ,接近WHO/FAO参考蛋白模式     

Molecular confirmation of the hybrid origin of the critically endangered western Mediterranean endemic <Emphasis Type="Italic">Sonchus pustulatus</Emphasis> (Asteraceae: Sonchinae)

The critically endangered composite Sonchus pustulatus Willk. despite being known from fewer than ten locations in southern Spain and northern Africa, has never been characterized in robust phylogenetic context. Here, we report molecular evidence that strongly supports a hybrid origin for S. pustulatus. Although parentage cannot be identified with certainty, analysis of DNA sequence variation from the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) supports a phylogenetic placement of S. pustulatus close to other species in the poorly known section Pustulati, whereas examination of chloroplast DNA (cpDNA) places S. pustulatus most closely with species from the sections Sonchus and Asperi. This is one of several instances of topological non-concordance reported for the genus Sonchus. Monophyly of S. pustulatus in both gene genealogies supports the null hypothesis of a single origin, and the relatively large amount of nucleotide substitutions is indicative of an origin in the range of millions of years. A hypothesis of a northern African origin of S. pustulatus followed by dispersal to the Iberian Peninsula during the Messinian salinity crisis/later Quaternary glaciations is proposed on the basis of biogeographic patterns and calibrated estimations of molecular evolution.     

Host specificity and suitability ofTephritis dilacerata [Dip.: Tephritidae]: A candidate for the biological control of perennial sow-thistle(Sonchus arvensis) [Compositae] in Canada

BioControl - The host specificity and suitability ofTephritis dilacerata Loew, a promising biocontrol agent of perennial sowthistle (Sonchus arvensis L.), were investigated. Sow-thistle is a...     

Two eudesmanolides from Sonchus macrocarpus

The aerial parts of Sonchus macrocarpus afforded, in addition to known triterpenes, two new eudesmanolides.     

Sesquiterpene lactones from Sonchus macrocarpus

Eight sesquiterpene lactones were isolated from the roots of Sonchus macrocarpus. The eudesmanolides 15-hydroxy-4β, 15-dihydroreynosin and 15-hydroxy-4β, 15, 11β, 13-tetrahydroreynosin were isolated for the first time.     

Cabbage Whitefly, Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae), Newly Discovered in Australia

Cabbage whitefly, Aleyrodes proletella , was found for the first time in Australia in January 1997. It was found on Brassica oleracea gp Capitata, Sonchus oleraceus and Euphorbia peplus in South Australia at McLaren Vale, Adelaide, Virginia and Renmark, and in Victoria at Red Cliffs.     

Uroleucon sonchi (Linnaeus) (Hemiptera: Aphididae) in Australia

Uroleucon sonchi, an aphid species of Palaearctic origin, is a recent adventive to Australia. It is now widespread in anthropic areas of all states and the Australian Capital Territory, principally on sowthistles ( Sonchus spp.) but also on lettuce. It is occasionally parasitised by Aphidius sonchi Marshall (Hymenoptera: Braconidae). Its possible economic importance in Australia is discussed. The species is also recorded for the first time from Norfolk and Philip Islands.     

Anatomy and evolution in the Macaronesian Sonchus subgenus Dendrosonchus (Compositae: Lactuceae)

The members of the genus Sonchus subgenus Dendrosonchus are woody perennials possessing the pachycaul construction which has been proposed as ancestral to that of modern trees and herbs. The endemic flora of Macaronesia, particularly the Canary Islands, is generally considered to be a Tertiary relict, although an opposing view concerning woody plants of island floras has recently been expressed. The anatomy of Dendrosonchus is examined and trends of evolution can be interpreted from the vessel elements of the secondary xylem. With the use of the length to breadth ratios of vessel elements a gradual trend from primitive to derived is illustrated for the members of each of the two sections of Dendrosonchus , which are considered to have evolved in parallel. The wood rays, features of the cypsela and stem anatomy are also shown to be useful in elucidating the evolution of a small, closely related group of plants. Sonchus arboreus in the section Atalanthus and S. brachylobus in the section Dendrosonchus are similar to the two ancestral types proposed for the subgenus. The most derived species are considered to be S. pinnatus subsp. palmensis in the section Atalanthus and S. acaulis in the section Dendrosonchus. The ancestral type for the genus is considered to have been woody and probably of the Dendrosonchus type.     

THE POTATO TUBER NEMATODE, DITYLENCHUS DESTRUCTOR THORNE, 1945; THE CAUSE OF EELWORM DISEASE IN BULBOUS IRIS

For about twenty-five years a fairly widespread disease of bulbous iris has been known, the cause of which has always been attributed to a biologic race of the stem eelworm Ditylenchus dipsaci (Kühn, 1857), Filipjev, 1936.
Thorne (1945) showed that the nematode causing rot in potato tubers is different from D. dipsaci and named it D. destructor. This nematode has since been reported from Mentha arvensis L. by Hurst (1948) and from Sonchus arvensis L. by Goodey & Goodey (1949).
Examination of nematodes from diseased iris bulbs showed them to possess rounded tail tips and six incisures on each lateral field; characters by which Ditylenchus destructor is distinguished from D. dipsaci.
Cross-inoculation experiments showed that the eelworm causing disease in potato tubers would invade and set up characteristic symptoms in iris bulbs and, in the opposite direction, the eelworm responsible for disease in iris bulbs would give rise to characteristic symptoms in potato tubers. Transfer was also effected from potato and iris to Mentha arvensis and from iris to Sonchus arvensis.
The history of the disease in bulbous iris is briefly reviewed and the biology of Ditylenchus destructor discussed and compared with that of D. dipsaci.
The conclusion that D. destructor is the nematode causing eelworm disease of bulbous iris has been reported earlier (Goodey, J. B. 1950).     

Ascosonchine, the enol tautomer of 4-pyridylpyruvic acid with herbicidal activity produced by Ascochyta sonchi

A new phytotoxic enol tautomer of 4-pyridylpyruvic acid, named ascosonchine, was isolated from the culture filtrate of Ascochyta sonchi. Such a leaf pathogen is a potential biocontrol agent of Sonchus arvensis, a perennial herbaceous weed occurring throughout the temperate regions of the world. Ascosonchine, characterised as (Z)-2-hydroxy-3-(4-pyridyl)-2-propenoic acid by spectroscopic methods, showed selective herbicidal properties, that are not associated with antibacterial, antifungal or zootoxic activities.     

Metabolomics Profiling of Tunisian Sonchus oleraceus L. Extracts and Their Antioxidant Activities

Sonchus oleraceus (L.) L. (Asteraceae) is an edible wild plant, known for its uses in traditional medicine. The aim of this study is to explore the phytochemical composition of the aerial parts (AP) and roots (R) of aqueous extracts of Sonchus oleraceus L. growing in Tunisia, using liquid chromatography-tandem mass spectrometry(LC/MS/MS), and determine the content of polyphenols and antioxidant activities. Results showed that aqueous extracts of AP and R contained, respectively, 195.25±33 μg/g and 118.66±14 μg/g gallic acid equivalent (GAE), and 52.58±7 μg/g and 3.2±0.3μg/g quercetin equivalent. AP and R extracts also contained tannins, 581.78±33 μg/g and 948.44±19 μg/g GAE. The AP extract in the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activities, hydroxyl radical scavenging (OH−) and in cupric reducing antioxidant activity (CUPRAC) assays were respectively 0.325±0.036 mg/mL, 0.053±0.018 mg/mL, 0.696±0.031 mg/mL and 60.94±0.004 μMTE/g, while the R extract using the same assays showed, 0.209±0.052 mg/mL, 0.034±0.002 mg/mL, 0.444±0.014 mg/mL and 50.63±0.006 μM Trolox equivalent/g, respectively. A total of 68 compounds were tentatively identified by LC/MS/MS in both extracts in which quinic acid, pyrogallol, osthrutin, piperine, gentisic acid, fisetin, luteolin, caffeic acid, gingerol, were the most abundant in the LC/MS/MS spectrum. Many of these metabolites were found for the first time in Tunisian Sonchus oleraceus L. which may take account for the antioxidant activities exhibited by the plant.     

Sesquiterpene lactone glucosides from Sonchus asper

From the methanolic extract of the roots of Sonchus asper, two new sesquiterpene glucosides, together with two known sesquiterpene glucosides and a known aglycone were isolated. Structures were identified as 11beta,13-dihydrourospermal A, 15-O-beta-D-glucopyranosyl-11beta,13-dihydrourospermal A, 15-O-beta-D-glucopyranosylurospermal A, 15-O-[6'-(p-hydroxyphenylacetyl)]-beta-D-glucopyranosylurosperm al A and 14-O-methylacetal-15-O-[6'-(p-hydroxyphenylacetyl)]-beta-D-+ ++glucopyranosylurospermal A, by spectroscopic means.     

THE BIOLOGY OF LETTUCE ROOT APHID

Lettuce root aphid, Pemphigus bursarius L., is a pest which sometimes causes considerable and widespread damage to crops of summer lettuce.
Its favourite primary host is Lombardy poplar. On hatching in spring, from eggs that have overwintered on this host, the fundatrices cause the development of hollow, flask-shaped galls on the leaf petioles. A fundatrix becomes enclosed within a gall, where it matures, and gives rise to between 100 and 250 young. These fundatrigeniae are all potential alatae and on developing wings leave the gall and migrate to lettuce and other secondary hosts; they reproduce rapidly.
Lettuce sown between mid-April and the end of May is most severely attacked, while lettuce sown in July escapes attack. The alternative secondary hosts belong to the Compositae, subfam. Liguliflorae, and although lettuce is preferred by the fundatrigeniae, Lapsana communis L. and Sonchus asper (L.) Hill often have big colonies of Pemphigus bursarius on their roots. The size of the mature apterae varies between hosts and is largest on lettuce and Sonchus asper.
All winged alienicolae are sexuparae and fly back to poplar. Thus alternative secondary hosts are not reservoirs for lettuce-infesting alatae.
The sexuparae begin appearing on lettuce from about the last week in August. They generally come up to the soil surface and settle around the 'collar' of the host plant, to mature and develop wings. Having flown back to the primary host, the sexuparae seek out crevices in the bark where they produce arostrate sexuales. The ovipara contains one egg, and after mating she crawls as far into the bark crevice as possible and oviposits.     

Karyological studies in Sonchus section Muritimi (Asteraceae) from the Iberian Peninsula

MEJÍAS, J. A. & VALDÉS, B., 1988. Karyologiepl studies in Sonchus section Madtimi (Asteraceae) from the Iberian Peninmula. Karyological data support the distinction of S. aquatilis Pourret and S. maritimus L. at the specific level. Karyological data and hybridization experiments support the idea that S. × novocaslcllanus Cirujano has been produced by the hybridization of S. crassifolius Pourret ex Willd. and S. maritimus L.     

First Record of Bremia lactucae Infecting Sonchus oleraceus and Sonchus asper in Brazil and its Infectivity to Lettuce

Bremia lactucae is recorded for the first time causing downy mildew on common sowthistle (Sonchus oleraceus) and spiny sowthistle (Sonchus asper) in Brazil. The disease and etiological agent are described. Pathogencity of sporangia obtained from S. oleraceus was tested on 12 species belonging to the Asteraceae, already recorded in the literature as hosts of B. lactucae, and four commonly cultivated varieties of lettuce. All four cultivars of lettuce, S. oleraceus and S. asper showed symptoms of the disease and sporulation of the pathogen 5 days after inoculation. It has been observed that the disease occurs on Sonchus spp. throughout the year in Viçosa (state of Minas Gerais), being more common on these two hosts than on lettuce. Both weeds are very common invaders of vegetable growing areas in Brazil. This indicates that those two hosts for the fungus may be important inoculum reservoirs for disease occurring in lettuce, highlighting the need for control of these weeds as part of the procedures aimed at controlling this disease. These results are also in agreement with the views that B. lactucae is split into host‐specific infra‐specific taxa. Lettuce and sowthistles are regarded as closely related, belonging to the same subfamily and tribe in the Asteraceae (Subfamily Cichorioideae: Tribe Lactuceae).     

Phylogenetic and morphological analysis of a new cliff-dwelling species reveals a remnant ancestral diversity and evolutionary parallelism in <Emphasis Type="Italic">Sonchus</Emphasis> (Asteraceae)

We describe a new cliff-dwelling species within Sonchus (Asteraceae): Sonchus boulosii and analyze its systematic position and evolutionary significance; in addition, we provide a key to the species of Sonchus in Morocco. Both morphological and ecological characteristics suggest a close relationship of S. boulosii with taxa of section Pustulati. However, ITS nrDNA and cpDNA matK markers indicate its uncertain position within the genus, but clear genetic differentiation from the remaining major clades. ITS phylogenetic trees show that likely evolutionary shifts to rocky habitat took place at least five times within genus Sonchus and that sect. Pustulati and S. boulosii clades have a clearly independent evolutionary origin. We postulate that the strong resemblance of S. boulosii to other rocky species reflects a phenomenon of homoplasy, probably driven by parallel evolutionary adaptations to the severe ecological constraints of its cliff face habitat. Therefore, a new section is also described, which includes S. boulosii as its sole representative: section Pulvinati. According to phylogenetic trees, the new clade may share its common ancestor with the clade comprising sections Maritimi and Arvenses, from which it is widely divergent in morphology and ecology, with the exception of Sonchus novae-zelandiae. However, the latter is a derived taxon, with high level of polyploidy unlike S. boulosii that shows 2n?=?18, basal chromosome number of the genus. Since sections Pulvinati and Pustulati seem to be quite old in Sonchus, we also hypothesize that some similarities, such as fruit morphology, may reflect the persistence of some primitive characteristics.     

Seed survival and periodicity of seedling emergence in twelve weedy species of Compositae

Achenes of 12 species of Compositae were collected in each of 3 years and mixed with the top 7.5 cm of sterilised soil which was confined in cylinders sunk in the ground outdoors and cultivated three times yearly. Seedling emergence was recorded for 5 yr and the numbers of viable seeds remaining then determined. Emergence of Arctium lappa, A. minus, Picris hieracioides, Taraxacum officinale, Sonchus arvensis and S. asper was mainly in spring. Seedlings of Chrysanthemum segetum, Lapsana communis, Anthemis cotula and Sonchus oleraceus were often most numerous in spring but also emerged at other times, while Matricaria matricarioides and M. recutita showed no consistent seasonal pattern of emergence. Except for C. segetum and A. cotula, in which there was evidence of innate dormancy imposed by the seed coat, the numbers of seedlings were greatest in the first year and thereafter decreased approximately exponentially from year to year. Few viable seeds of A. lappa or A. minus remained after 5 yr and those of T. officinale, P. hieracioides and S. arvensis accounted for less than 1.5% of the seeds sown. Seed survival was greatest in the annual weeds and ranged from 2.1% (S. asper) to 8.6% (M. matricarioides) after 5 yr.