Species In Yunnan Research Articles

Natural incidence of Fusarium species and fumonisins B1 and B2 associated with maize kernels from nine provinces in China in 2012

Fusarium species, which can produce mycotoxins, are the predominant pathogens causing maize ear rot, a disease that results in severe economic losses and serves as a potential health risk for humans and animals. A survey was conducted in 2012 to investigate the contamination of maize by Fusarium species and fumonisins B1 and B2. A total of 250 maize samples were randomly collected from nine provinces (Hebei, Shanxi, Inner Mongolia, Yunnan, Sichuan, Guizhou, Heilongjiang, Liaoning and Ningxia) in China. Fusarium species were isolated and identified using morphological (electron microscope) and molecular methods (polymerase chain reaction (PCR) and sequencing). Fumonisins B1 and B2 were analysed using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) with OPA (2-Mercaptoethanol, o-phthaldialdehyde) post-column derivatisation. A total of 2321 Fusarium isolates (20.7%) were obtained from all the samples. These isolates included nine Fusarium species, namely, F. graminearum, F. verticillioides, F. subglutinans, F. proliferatum, F. temperatum, F. oxysporum, F. equiseti, F. meridionale and F. chlamydosporum. The incidence of occurrence of Fusarium species in Guizhou was the highest, while in Inner Mongolia it was the lowest. F. verticillioides was the dominant species of maize ear rot in Liaoning, Sichuan, Hebei and Ningxia. F. graminearum was the dominant species in Yunnan, Guizhou and Shanxi. F. subglutinans was the dominant species in Heilongjiang. F. verticillioides and F. graminearum percentages were the same in Inner Mongolia. The incidence of fumonisins in Liaoning was high (up to 81.0%) and in Heilongjiang low (up to 10.3%). Except Shanxi, more than 50% of maize samples from other provinces were contaminated with fumonisins, with concentrations less than 500 ng g−1. About 33% of maize samples from Yunnan were contaminated with high levels of fumonisins, and average of fumonisin levels were 5191 ng g−1. Fusarium species causing maize ear rot in different areas in China were highly diverse and such areas with exposure to high levels of fumonisin contamination have a potential health risk for human and animals.

Studies on the Nutrition Component of Fresh Shoots of Large-Sized Cluster Bamboo from Yunnan, China

Nutrition components of bamboo shoots sampled from 6 large-sized and shoots-based bamboo species in Yunnan were analyzed in this paper. The results showed that bamboo shoots were naturally green food with merits of high protein, fiber, ash content, low sugar and low fat, however with defects of sulfur-containing amino acid and calcium deficiency, consisting of essential amino acid such as aspartic acid, phenylalanine, tryptophan and lysine, also including other important microelements as iron, zinc and manganese, and vitamin E.

Members of Bemisia tabaci (Hemiptera: Aleyrodidae) cryptic species and the status of two invasive alien species in the Yunnan Province (China).

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex that includes some of the most significant pests of agriculture and horticulture worldwide. To understand the diversity and distribution of B. tabaci cryptic species in Yunnan, a famous biodiversity hotspot in China, a large-scale sampling was conducted from year 2010 to 2013 in 10 prefectures. Mitochondrial cytochrome oxidase I gene sequences were used to identify different cryptic species. Phylogenetic analyses were performed using Bayesian methods to assess the position of a new B. tabaci cryptic species in the context of the B. tabaci diversity in Asia. The survey indicates at least eight B. tabaci cryptic species are present in Yunnan, two invasive (MEAM1 and MED) and six indigenous (China 2, China3, China 4, Asia I, Asia II 1, and Asia II 6), MEAM1, MED, and Asia I being the three predominant cryptic species in Yunnan. Compared with MEAM1, MED has a wider distribution. Based on molecular data, a new cryptic species, here named China 4, was identified that appears to be related to China 1, China 2, and China 3. Future efforts should focus on the interactions between predominant B. tabaci cryptic species and begomoviruses and on the development of effective control strategies.

Checklist of fishes of Yunnan

Based on extant literatures and taking into accounts updated results of taxonomy and phylogeny, we have updated this checklist of fishes present in Yunnan, including the number of taxa and drainage areas. As of 2013, there were 13 orders, 42 families, 198 genera and 620 valid species recorded in Yunnan Province, of which 586 were native species, 34 alien species, 254 species endemic to Yunnan, and 152 species only occuring in Yunnan within China. The number of species in Yunnan accounts for 39.17% of China's total fish species (of which there are 1 583 recorded freshwater fish species according to data present in Fishbase), and of these 6 families and 66 genera only occur in Yunnan. The number of fish species of the six major drainages in Yunnan were as follows: 202 in Pearl River, 183 in Lancangjiang River (upper Mekong), 142 in Jinshajiang River (upper Yangtze), 120 in Red River, 84 in Irrawaddy Drainage, 77 in Nujiang-Salween Drainage. There are also 99 endangered species of fish occurring in Yunnan, among them 23 species protected by the national and/or the provincial government, including 2 species of national key protected animal class one, 4 species of national key protected animal class two, 17 species of Yunnan provincial protected animal. Totally, 43 species were listed in China Red Data Book of Endangered Animals, Pisces; 73 species were listed in China Species Red List Vol. 1; 50 species were listed in endangered categories of IUCN Red List; and 3 species were listed in the Appendix 2 of CITES. The Chinese name, Latin name, synomyns, distribution and literatures of the 620 species of fishes in Yunnan are listed.

Genetic diversity and differentiation of Dendrocalamus membranaceus (Poaceae: Bambusoideae), a declining bamboo species in Yunnan, China, as based on Inter-Simple Sequence Repeat (ISSR) Analysis.

Dendrocalamus membranaceus Munro is a woody bamboo with a high economic and ecological value that often occurs as natural stands, such as in the large-scale forested areas of China’s Yunnan Province. Due to its overexploitation, the habitat of D. membranaceus in Yunnan has been dramatically reduced, and the quality of the stands has declined. As a preliminary analysis in considering the effective protection for these germplasm resources, we assessed the genetic diversity of 12 natural populations in Yunnan, using inter-simple sequence repeat (ISSR) markers. From 10 ISSR primers, we generated 155 bands, of which 153 were polymorphic (98.71%). Compared with other species in the genus, this species demonstrated a greater genetic diversity (S = 0.349) and lower genetic differentiation (GST = 0.252). Our analysis of molecular variance revealed that the genetic differentiation among the populations is significant. A large proportion of the genetic variation (78.95%) resides among the individuals within populations, whereas only 21.05% are found among populations. Mantel tests indicated no significant correlation between genetic and geographic distances among the populations. Given the low sexual reproducibility and characteristics of monocarpic plants, we recommend implementing in situ conservation measures for all of the D. membranaceus populations in Yunnan and collecting sufficient samples for ex situ conservation. Furthermore, the conservation area should be extended to its main natural habitats, the Lancang-Mekong River Valley.

The potential roles of interspecific pollination in natural hybridization of Rhododendron species in Yunnan, China

The potential roles of interspecific pollination in natural hybridization of Rhododendron species in Yunnan, China

Characterization of DNAbeta associated with begomoviruses in China and evidence for co-evolution with their cognate viral DNA-A.

Eighteen samples of begomoviruses isolated from tobacco, tomato and weed species in Yunnan, China were found to be associated with DNAbeta molecules, for which the complete nucleotide sequences were found to contain 1333-1355 nt. The 18 DNAbeta molecules identified consist of three main types, each associated with a different begomovirus species: 72-99 % nucleotide identity was found within one type, but only 39-57 % identity was found between types. All the DNAbeta molecules reported here and elsewhere contain a 115 nt conserved region that has 93-100 % identity with a consensus sequence, and have a common ORF encoding 118 amino acids on the complementary strand (designated C1). Co-agroinoculation of the DNA-A component of Tomato yellow leaf curl China virus tobacco isolate Y10, with its associated DNAbeta (Y10beta), shows this DNAbeta to be involved in symptom induction in tobacco and tomato. The in-frame ATG mutation of C1 of Y10beta caused much milder symptoms as compared with wild Y10beta, indicating a functional role for this ORF. Pairwise nucleotide sequence identity comparisons of DNAbeta molecules and their cognate viral DNA-A molecules indicate that DNAbeta molecules have co-evolved with their cognate helper viruses. Recombination between DNAbeta molecules is documented and a DNAbeta species concept is proposed and discussed.

Genetic structure and heterozygosity variation between generations of Ophiopogon xylorrhizus (Liliaceae s.l.), an endemic species in Yunnan, southwest China.

Inbreeding depression and evolution of mating systems have been well discussed in the literature (Lande and Schemske, 1985; Schemske and Lande, 1985; Wolfe, 1993; Holsinger, 1988; Carr and Dudash, 1996). These studies all have a common assumption, i.e., homozygosity can cause deleterious recessive or partially recessive lethal alleles to show their effects on the phenotype, so heterozygotes are always more fit than homozygotes (Holtsford, 1996). This implies that inbreeding depression results from inbreeding and excessive homozygotes. Estimates of inbreeding depression usually depend on the fitness differences between selfed and outcrossed progeny. However, inbreeding depression has been generally underestimated, because it is difficult to measure at all possible stages of the life cycle (Charlesworth and Charlesworth, 1987). If inbreeding depression occurred in a species, it would lead to changes of homozygote frequency between seed populations and maternal populations or adult populations. The variation of homozygote frequency between generations may be a better parameter to describe inbreeding depression. Ophiopogon xylorrhizus Wang et Dai is a herbaceous perennial, endemic to Mengla County, Yunnan Province, Southwest China. Fewer than 1500 individuals located in eight disjunct populations cover an area of ca. 30× 20 km2 and the

A New Combination in Bambusa (Gramineae-Bambusoideae)

A new combination, Bambusa membranacea (Munro) Stapleton & N. H. Xia, is made for a widespread and economically important bamboo from Burma, Indo-China, and Yunnan Province of China. On encountering this species in Yunnan, it was seen that all its vegetative characteristics were those of Bambusa Schreber rather than Dendrocalamus Nees. This prompted a more detailed analysis of herbarium material. It was found that despite having some floral characteristics of Dendrocalamus, prophylls subtending the synflorescence were consistently 2-keeled. This has been adopted as the principal criterion for separating the two genera. To improve consistency in vegetative and floral circumscription of the genera, it is felt desirable to transfer this species.

The possible role of Yunnan, China, in the origin of contemporary citrus species (rutaceae)

The primitive center of origin of Citrus species has been a subject of speculation and discussion for some time. Japanese Citrus taxonomist Tanaka concluded that the center of origin was northeastern India and northern Burma. He ascribed a secondary role in the origin and distribution of Citrus species to Yunnan and surrounding areas of China on the basis of his belief that there were no important native species. These conclusions were based on incomplete information that was available over 30 yr ago, but important new evidence from Yunnan challenges Tanaka’s ideas on the origin of Citrus species. This report describes the diversity of indigenous primitive and advanced Citrus species in Yunnan and the interaction of topography and climate with the geographic distribution of these species. Numerous river systems arise in or traverse Yunnan and flow to Burma, Indo-China, and southern and central China, thus providing a natural plant dispersal mechanism. The authors suggest that the substantial portion of the Citrus gene pool represented in the rich diversity of indigenous species reported in recent Chinese surveys and the available natural dispersal mechanism provide strong evidence that Yunnan and nearby areas of China played a critical role in the origin and distribution of modern Citrus species.