Genus Lycium Research Articles

Variation of Sweet Chemicals in Different Ripening Stages of Wolfberry Fruits

ObjectiveTo evaluate the variation of sweet chemicals (sugars and betaine) in fruits of six species in genus Lycium L. i.e. Lycium truncatum, L. cylindricum, L. dasystemum, L. dasystemum var. rubricaulium, L. chinense, and L. barbarum harvested at three different ripening stages. MethodsA simple and effective method based on UPLC-ELSD was developed for the simultaneous determination of two monosaccharides (glucose and fructose), two disaccharides (sucrose and maltose), one sugar alcohol (xylitol), and betaine in wolfberry fruits (goji berries) of genus Lycium L. ResultsThe six species of wolfberry fruits harvested at the three different ripening stages were evaluated in sugars and betaine contents. Fructose and glucose were the predominant sugars in mature wolfberry fruits. Fructose, glucose, and betaine, as well as total sugar contents, increased continually over the ripening process. L. truncatum and L. dasystemum had higher contents of sugars and betaine than the other species. ConclusionUPLC-ELSD is a simple, reliable and effective method for analysis of the sweet chemicals in wolfberries. Wolfberry fruits at the different ripening stages were significant different in sweetness. L. truncatum and L. dasystemum could be the potential sources of wolfberry fruit sources.

Systematic Review of Chemical Constituents in the Genus Lycium (Solanaceae).

The Lycium genus is widely used as a traditional Chinese medicine and functional food. Many of the chemical constituents of the genus Lycium were reported previously. In this review, in addition to the polysaccharides, we have enumerated 355 chemical constituents and nutrients, including 22 glycerogalactolipids, 29 phenylpropanoids, 10 coumarins, 13 lignans, 32 flavonoids, 37 amides, 72 alkaloids, four anthraquinones, 32 organic acids, 39 terpenoids, 57 sterols, steroids, and their derivatives, five peptides and three other constituents. This comprehensive study could lay the foundation for further research on the Lycium genus.

Polyphenols from wolfberry and their bioactivities

Nine new phenylpropanoids, one new coumarin, and 43 known polyphenols were isolated from wolfberry. Their structures were determined by spectroscopic analyses, chemical methods, and comparison of NMR data. Polyphenols, an important type of natural products, are notable constituents in wolfberry. 53 polyphenols, including 28 phenylpropanoids, four coumarins, eight lignans, five flavonoids, three isoflavonoids, two chlorogenic acid derivatives, and three other constituents, were identified from wolfberry. Lignans and isoflavonoids were firstly reported from wolfberry. 22 known polyphenols were the first isolates from the genus Lycium. This research presents a systematic study on wolfberry polyphenols, including their bioactivities. All these compounds exhibited oxygen radical absorbance capacity (ORAC), and some compounds displayed DPPH radical scavenging activity. One compound had acetylcholinesterase inhibitory activity. The discovery of new polyphenols and their bioactivities is beneficial for understanding the scientific basis of the effects of wolfberry.

<p align="left">Lycium ningxiaense, a replacement name for Lycium parvifolium T.Y. Chen & Xu L. Jiang (Solanaceae)

The genus Lycium Linnaeus (1753: 191) is one of the largest genera in Solanaceae Jussieu (1789: 124), with approximately 92 species in the monogeneric tribe Lycieae Hunziker (1977: 28; Levin et al. 2011). It is disjunctly distributed in temperate to subtropical regions between the northern and southern hemispheres, mainly in North America, South America, southern Africa, and Eurasia (Zhang et al. 1994, Fukuda et al. 2001). It is characterized by spiny shrubs and small trees, fasciculate leaves, campanulate calyx, and by fleshy and juicy berry. Traditionally Lycium berry has been used medicinally worldwide.

Neolignanamides, Lignanamides, and Other Phenolic Compounds from the Root Bark of Lycium chinense

Seven new neolignanamides (1-7), including two pairs of cis- and trans-isomers, and a new lignanamide (8) were isolated from the EtOAc-soluble fraction of an EtOH extract of the root bark of Lycium chinense, together with 22 known phenolic compounds (9-30), four of which were obtained from the genus Lycium for the first time. Compounds 5, 6, and 7 are unusual dimers having a rare connection mode between the two cinnamic acid amide units, while compounds 6, 7, and 8 are the first naturally occurring dimers derived from two dissimilar cinnamic acid amides. The cinnamic acid amides, neolignanamides, and lignanamides possess moderate radical-scavenging activity against the DPPH (2,2-diphenyl-1-picrylhydrazyl) and superoxide radicals.

A new generic circumscription in tribe Lycieae (Solanaceae)

AbstractTribe Lycieae (Solanaceae) currently includes ca. 92 species in three genera. Two genera account for only a few species, as Phrodus is monotypic and Grabowskia includes just four species. By contrast, Lycium is one of the largest genera in the family, with ca. 88 species and over 95% of the species diversity in tribe Lycieae. Previous molecular studies have suggested that Lycium is paraphyletic and that species of Grabowskia are nested within Lycium. These studies also suggested that the genus Grabowskia was monophyletic, but questioned the integrity of species within it. Likewise, although the genus is defined by a unique fruit structure, morphology is of limited use in distinguishing species within Grabowskia. Depending on the study, Phrodus microphyllus has been placed either as sister to the rest of the tribe or nested within Lycium. In the present study we include data from two nuclear regions (granule‐bound starch synthase and nitrate reductase) and four plastid spacer regions (trnH‐pbsA, trnDGUC‐trnTGGU, rpl32‐trnLUAG, ndhF‐rpl32) to more clearly resolve evolutionary relationships among genera within the tribe and among species in Grabowskia. Results confirm that Lycium is paraphyletic and includes a monophyletic Grabowskia. However, inclusion of multiple accessions of several Grabowskia species does not support the maintenance of distinct species in the genus. In addition, Phrodus microphyllus is moderately supported as basal within the tribe. Given these results, which are further strengthened by morphological and cytological data, we synonymize three Grabowskia species with Grabowskia boerhaviifolia and include this species within Lycium, using its basionym, Lycium boerhaviifolium L. f. Additionally, we transfer Phrodus microphyllus to the genus Lycium, proposing a new combination: Lycium bridgesii (Miers) Levin, Miller & Bernardello. Tribe Lycieae is now monotypic, including the single genus Lycium.

Out of America to Africa or Asia: Inference of Dispersal Histories Using Nuclear and Plastid DNA and the S-RNase Self-incompatibility Locus

The plant genus Lycium (Solanaceae) originated in the Americas and includes approximately 85 species that are distributed worldwide. The vast majority of Old World species occur in southern Africa and eastern Asia. In this study, we examine biogeographic relationships among Old World species using a phylogenetic approach coupled with molecular evolutionary analyses of the S-RNase self-incompatibility gene. The phylogeny inferred from nuclear granule-bound starch synthase I (GBSSI), nuclear conserved ortholog set II (COSII) marker C2_At1g24360, and plastid spacer data (trnH-pbsA, trnD(GUC)-trnT(GGU), rpl32-trnL(UAG), and ndhF-rpl32) includes a clade of eastern Asian Lycium nested within the African species, suggesting initial dispersal from the Americas to Africa, with subsequent dispersal to eastern Asia. Molecular dating estimates suggest that these dispersal events occurred relatively recently, with dispersal from the Americas to Africa approximately 3.64 Ma (95% highest posterior density [HPD]: 1.58-6.27), followed by subsequent dispersal to eastern Asia approximately 1.21 Ma (95% HPD: 0.32-2.42). In accordance, the S-RNase genealogy shows that S-RNases isolated from Old World species are restricted to four lineages, a subset of the 14 lineages including S-RNases isolated from New World Lycium species, supporting a bottleneck of S-RNase alleles concomitant with a single dispersal event from the Americas to the Old World. Furthermore, the S-RNase genealogy is also consistent with dispersal of Lycium from Africa to Asia, as eastern Asian alleles are restricted to a subset of the lineages that also include African alleles. Such a multilocus approach, including complementary data from GBSSI, COSII, plastid spacer regions, and S-RNase, is powerful for understanding dispersal histories of closely related species.

A TALE OF TWO CONTINENTS: BAKER'S RULE AND THE MAINTENANCE OF SELF-INCOMPATIBILITY IN LYCIUM (SOLANACEAE)

Over 50 years ago, Baker (1955, 1967) suggested that self-compatible species were more likely than self-incompatible species to establish new populations on oceanic islands. His logic was straightforward and rested on the assumption that colonization was infrequent; thus, mate limitation favored the establishment of self-fertilizing individuals. In support of Baker's rule, many authors have documented high frequencies of self-compatibility on islands, and recent work has solidified the generality of Baker's ideas. The genus Lycium (Solanaceae) has ca. 80 species distributed worldwide, and phylogenetic studies suggest that Lycium originated in South America and dispersed to the Old World a single time. Previous analyses of the S-RNase gene, which controls the stylar component of self-incompatibility, have shown that gametophytically controlled self-incompatibility is ancestral within the genus, making Lycium a good model for investigating Baker's assertions concerning reproductive assurance following oceanic dispersal. Lycium is also useful for investigations of reproductive evolution, given that species vary both in sexual expression and the presence of self-incompatibility. A model for the evolution of gender dimorphism suggests that polyploidy breaks down self-incompatibility, leading to the evolution of gender dimorphism, which arises as an alternative outcrossing mechanism. There is a perfect association of dimorphic gender expression, polyploidy, and self-compatibility (vs. cosexuality, diploidy, and self-incompatibility) among North American Lycium. Although the association between ploidy level and gender expression also holds for African Lycium, to date no studies of mating systems have been initiated in Old World species. Here, using controlled pollinations, we document strong self-incompatibility in two cosexual, diploid species of African Lycium. Further, we sequence the S-RNase gene in 15 individuals from five cosexual, diploid species of African Lycium and recover 24 putative alleles. Genealogical analyses indicate reduced trans-generic diversity of S-RNases in the Old World compared to the New World. We suggest that genetic diversity at this locus was reduced as a result of a founder event, but, despite the bottleneck, self-incompatibility was maintained in the Old World. Maximum-likelihood analyses of codon substitution patterns indicate that positive Darwinian selection has been relatively strong in the Old World, suggesting the rediversification of S-RNases following a bottleneck. The present data thus provide a dramatic exception to Baker's rule, in addition to supporting a key assumption of the Miller and Venable (2000) model, namely that self-incompatibility is associated with diploidy and cosexuality.

EVOLUTIONARY RELATIONSHIPS IN TRIBE LYCIEAE (SOLANACEAE)

We examine evolutionary relationships among the three genera in tribe Lycieae using DNA sequence data from the nuclear granule-bound starch synthase gene (GBSSI, waxy). Tribe Lycieae is comprised of the large cosmopolitan genus Lycium and the predominately South American genera Grabowskia and Phrodus. Phylogenetic results strongly suggest that Lycium contains Grabowskia and may also include Phrodus. Further, we examine relationships among several clades of American Lycium and within the monophyletic Old World lineage. This study has the largest taxon sampling to date for tribe Lycieae, with 85% of the named species. Increased sampling within eastern Asia and South America, with the world’s highest species-richness of Lycium, as well as the addition of more rapidly evolving genetic markers, are the areas on which to focus future work.

Quantification of Zeaxanthin Dipalmitate and Total Carotenoids in Lycium Fruits (Fructus Lycii)

An HPLC-DAD method has been developed to quantitatively analyze for the content of zeaxanthin dipalmitate, a major carotenoid in Fructus Lycii, in different species of the genus Lycium. Determination was performed using an Alltima C18 column with the mobile phase consisting of acetonitrile and dichloromethane (42:58). The total contents of carotenoids in these samples were also determined by using UV spectrophotometric assay. Total carotenoid concentrations of different Fructus Lycii are within the range of 0.03-0.5%. Zeaxanthin dipalmitate is a predominant carotenoid, comprising 31-56% of the total carotenoids in Fructus Lycii. This study is the first systematic quantification of the carotenoids in the fruits of different Lycium species. The results demonstrated that these methods are reliable and facile techniques for rapid analysis of carotenoids for crude drug and plant-derived food supplements.

ASSOCIATION OF PLOIDY AND SEXUAL SYSTEM IN LYCIUM CALIFORNICUM (SOLANACEAE)

In North American Lycium (Solanaceae), the evolution of gender dimorphism has been proposed as a means of restoring outcrossing after polyploidization causes the loss of self-incompatibility. Previous studies of this process in Lycium focused on comparisons between species that differ in ploidy. We examined intraspecific variation in floral morphology and DNA content in populations of L. californicum to determine correlations between sexual system and cytotype. We also used nuclear ITS and GBSSI sequence data to determine whether diploid and polyploid forms represent the same phylogenetic species, and the phylogeographic relationships among populations and ploidy levels. Within populations, no variation in ploidy was found, although among populations there was a perfect correspondence between sexual system and cytotype. Diploid populations were all hermaphroditic, whereas tetraploid populations were all gender dimorphic. There was no clear geographic pattern to the occurrence of diploid and tetraploid forms. Phylogenetic analysis confirms that L. californicum, regardless of ploidy, forms a monophyletic group within the genus Lycium. Sequences from diploid and polyploid individuals did not form reciprocally monophyletic clades, indicating either multiple gains of polyploidy, ongoing gene flow between cytotypes, or lack of lineage sorting since the evolution of polyploidy. The correspondence between ploidy and sex expression is consistent with the hypothesis that polyploidization triggers the evolution of gender dimorphism in this and other Lycium species.

ASSOCIATION OF PLOIDY AND SEXUAL SYSTEM IN LYCIUM CALIFORNICUM (SOLANACEAE)

In North American Lycium (Solanaceae), the evolution of gender dimorphism has been proposed as a means of restoring outcrossing after polyploidization causes the loss of self-incompatibility. Previous studies of this process in Lycium focused on comparisons between species that differ in ploidy. We examined intraspecific variation in floral morphology and DNA content in populations of L. californicum to determine correlations between sexual system and cytotype. We also used nuclear ITS and GBSSI sequence data to determine whether diploid and polyploid forms represent the same phylogenetic species, and the phylogeographic relationships among populations and ploidy levels. Within populations, no variation in ploidy was found, although among populations there was a perfect correspondence between sexual system and cytotype. Diploid populations were all hermaphroditic, whereas tetraploid populations were all gender dimorphic. There was no clear geographic pattern to the occurrence of diploid and tetraploid forms. Phylogenetic analysis confirms that L. californicum, regardless of ploidy, forms a monophyletic group within the genus Lycium. Sequences from diploid and polyploid individuals did not form reciprocally monophyletic clades, indicating either multiple gains of polyploidy, ongoing gene flow between cytotypes, or lack of lineage sorting since the evolution of polyploidy. The correspondence between ploidy and sex expression is consistent with the hypothesis that polyploidization triggers the evolution of gender dimorphism in this and other Lycium species.

A cytogenetic study of the functionally dioecious species in the genus Lycium (Solanaceae)

A cytogenetic study of five species of Lycium and an interspecific hybrid from southern Africa, is presented. All these taxa have a basic chromosome number of 12. This is the first report on chromosome numbers for L. arenicolum (hexaploid), L. horridum (tetraploid), L. tetrandrum (hexaploid) and L. villosum (tetraploid). Various meiotic abnormalities were observed, such as univalents, laggards during anaphase I, micronuclei during telophases I and II, and anaphase bridges. Cell fusion occurs frequently in the studied species, with apparently no effect on ploidy levels within them. The abnormalities observed in L. arenicolum indicate a lack of chromosome homology and, therefore, suggest a hybrid origin for this species.

Taxonomic account of Lycium (Solanaceae) in Australia

The genus Lycium L. is represented in Australia by one endemic (L. australe F. Muell.) and three naturalized alien species (L. ferocissimum Miers, L. barbavum L. and L. afrum L.). L. macvocalyx Domin, originally described as a new species from Australia, is a synonym of L. ferocissimum.

A Monographic Study of the Genus Lycium of the Western Hemisphere

A Monographic Study of the Genus Lycium of the Western Hemisphere