Microsatellite markers for Saussurea gnaphalodes (Asteraceae), a native Himalayan mountain species

? Premise of the study: Microsatellite markers were developed in Saussurea gnaphalodes to investigate its genetic variation and population structure. ? Methods and Results: Using the combined biotin capture method, 46 microsatellite primer sets were isolated and characterized across 48 S. gnaphalodes individuals from three Tibetan populations. Seventeen of these markers showed polymorphism, and the number of alleles ranged from two to 17. The observed and expected heterozygosities per population ranged from 0 to 0.938 and from 0 to 0.905, respectively. ? Conclusions: These markers provide a useful tool to investigate the genetic diversity and population structure of S. gnaphalodes, and to facilitate further studies on conservation and utilization.     

Effect of burning on selected soil parameters in a grass fallow shifting cultivation system in Bhutan

Grass fallow shifting cultivation is an important land use practice in the highlands of Bhutan. Part of the nutrient pool contained in soil organic matter is made available for the traditional buckwheat (Fagopyrum tataricum) crop through a highly labor intensive system exposing 250–500 MT soil ha⁻¹ to temperatures of 500°C and above. Dry topsoil is collected in mounds and burned using plant biomass or manure and soil organic matter as fuel. Labor input ranged from 150–401 days ha⁻¹ with land preparation accounting for 65–85% of the total requirement. The burning increased soil pH from 6.0 to 6.9 and available K from 34 to 69 mg kg⁻¹. Soil organic C and total N were reduced from 3.3 and 0.17% to 0.8 and 0.08%, respectively. Release of P from soil organic matter and plant material and reduction in C/N ratio resulting in increased N availability are considered the most essential effects required for good crop yields. Through the burning about 16 MT of C and 470 kg N ha⁻¹ are released into the atmosphere. Fallow periods of 15–20 years are required for the system to be sustainable. The research was supported by the Department of Agriculture. Royal Government of Bhuttan and the Swiss Association for Technical Assistance The research was supported by the Department of Agriculture. Royal Government of Bhuttan and the Swiss Association for Technical Assistance     

<Emphasis Type="Italic">Roseovarius tibetensis</Emphasis> sp. nov., a halophilic bacterium isolated from Lake LongmuCo on Tibetan Plateau

Two Gram-stain negative halophilic strains, designated as LM2^T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2^T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172^T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084^T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C_18:1ω7c/C_18:1ω6c, C_16:0, C_19:0 cyclo ω8c, and 11-methyl C_18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2^T and LM4, 24.9% relatedness between LM2^T and R. tolerans EL-172^T, and 36.3% relatedness between LM4 and R. tolerans EL-172^T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2^T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2^T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2^T (= CGMCC 1.16230^T = KCTC 62028^T).     

Benefits and challenges of maintaining national plant pest lists: an analysis of agricultural pests in Bhutan

Developing and maintaining national plant pest lists helps fulfil international obligations for trading countries, and also provides a foundation for national biosecurity systems. However, if done, lists and analyses are rarely made publically available. We compiled a national plant pest list for Bhutan, a relatively small but agriculturally diverse country for which plant protection is a recent discipline. We treated this pest list as a case study to test the benefits and challenges of maintaining such lists. Six hundred and forty‐five pest species were recorded across 64 different crops. Of those, only 17.0% were listed for Bhutan in the widely used CABI Crop Protection Compendium. Most species (86.4%) were first recorded during the initial discovery phase (1985–88) of a long‐running European Community funded aid programme. Regular taxonomic changes means keeping pest lists up to date requires both effort and expertise (27.0% of the 407 species identified by 1988 have since undergone name changes). Confidence in taxonomic identifications reduced drastically as access to international expertise decreased, from about 69.1% of species being identified with high confidence prior to 1988 to 8.1% afterwards. Many recent records lacked reference material, and voucher specimens for older material are mostly located internationally, making any revision challenging. Of the best represented taxa, greatest taxonomic uncertainty was for nematodes and viruses. Similar patterns were evident for the 112 damaging pest species, defined as those that at least occasionally and locally cause significant losses or require management actions within Bhutan. Of the damaging pests identified to species, all but one was also recorded in India, Bhutan's most important trading partner, and only 16 were restricted to Asia. New damaging pests continue to be recorded, but only five species may represent new incursions since 1988. National pest lists are critical, but to be of greatest value they need to capture taxonomic uncertainty, and focus on pests of greatest significance. For most countries, the development, maintenance and use of a national plant pest list will require ongoing regional and global cooperation to overcome taxonomic impediments, and to maximise the benefits of such lists in terms of facilitating trade and guiding domestic biosecurity activities.     

Identification of root-colonizing AM fungal communities and their responses to short-term climate change and grazing on Tibetan plateau

The molecular diversity of arbuscular mycorrhizal (AM) fungi remains largely unexplored in sedge-dominated ecosystems, much less their responses to global climate change and grazing. To determine the molecular diversity of AM fungi and how they are affected by climate change and grazing, we examined AM fungal communities inside roots in a sedge meadow ecosystem (4875 m a.s.l.) undergoing 4 yr. of fully factorial manipulations of experimental warming, snow addition and grazing on the Tibetan Plateau. A total of 21 AM fungal virtual taxa (VTs) were identified, including one new genus-like clade and one new VT unrecorded in the MaarjAM database. However, we did not observe significant effects of climate change and/or grazing on AM fungal abundance, diversity and community composition. These results indicate that diverse AM fungal taxa inhabit in the sedge-dominated meadows on the Tibetan Plateau, but the AM fungal communities were not sensitive to short-term climate change and grazing.     

Soil carbon and nitrogen stocks in forests along an altitudinal gradient in the eastern Himalayas and a meta‐analysis of global data

High‐altitude soils potentially store a large pool of carbon (C) and nitrogen (N). The assessment of total C and N stocks in soils is vital to understanding the C and N dynamics in terrestrial ecosystems. In this study, we examined effects of altitude and forest composition on soil C and N along a transect from 317 to 3300 m a.s.l. in the eastern Himalayas. We used meta‐analysis to establish the context for our results on the effects of altitude on soil C, including variation with depth. Total C and N contents of soils significantly increased with altitude, but decreased with soil depth. Carbon and N were similarly correlated with altitude and temperature, and temperature was seemingly the main driver of soil C along the altitudinal gradient. Altitude accounted for 73% of the variation in C and 47% of the variation in N stocks. Soil pH and cation exchange capacity were correlated with both soil C and N stocks. Increases in soil C and N stocks were related to forest composition, forest basal area as well as quantity of leaf litter that were in turn influenced by altitude and temperature. Concentrations of C in foliage increased by 2.1% for every 1000 m rise in altitude, while that in leaf litter increased by 2.3%.     

Prion Protein Polymorphisms and Estimation of Risk of Scrapie in East Asian Sheep

Allele and genotype frequency distributions of prion protein (PrP) polymorphisms at three codons, 136, 154, and 171, in East Asian sheep were determined by PCR–RFLP analysis using 553 animals from nine local breeds of the northern group and four local breeds of the southern group. Based on the genotype distribution, the risk score for scrapie was estimated. Among the local breeds, ARQ appeared predominantly (0.7701–1), followed by ARH and ARR. From such a biased allele distribution, it was difficult to ascertain the prevalent genetic relationships. A marked difference in allele frequencies between the northern and southern groups was seen (P < 0.0001). The East Asian sheep had ARQ at the highest frequency (0.8834); in European sheep it was 0.5317. According to an assessment of scrapie risk in the PrP genotype classes, the predominant ARQ/ARQ in East Asian sheep corresponded to the risk score of R4. This finding suggests that East Asian sheep have a high level of genetic susceptibility to scrapie.     

Phylogenetic Relationships among Indigenous Sheep Populations in East Asia based on Five Informative Blood Protein and Nonprotein Polymorphisms

The phylogenetic relationships among 23 local sheep breeds and varieties in East Asia were determined based on allele frequency data for five informative and polymorphic blood protein and nonprotein loci (transferrin, arylesterase, hemoglobin-β, X-protein, and potassium transport) using electrophoresis and ion-densitometric techniques. Comparatively striking differences in the frequency distributions, especially of hemoglobin-β and X-protein alleles, were seen between the northern population of the Khalkhas, Bhyanglung, Baruwal, Jakar, Sakten, and five Chinese breeds and the southern population of the Bengal, Kagi, Lampuchhre, Myanmar, and Sipsu breeds. Clustering analyses using UPGMA and NJ methods and principal component analysis, using the data of all populations and loci tested, clearly demonstrated the difference. The two population groups are divided by the boundary of the Himalayas, and each diverged into three subgroups: Mongolian, Tibetan, and Himalayan groups in the north and Indian groups I, II, and III in the south. It was noted that the genetic differentiation of populations was more distinct in the northern group. These findings strongly suggest the existence of at least two large and phylogenetically different gene pools of sheep in East Asia.     

Non-linear temperature sensitivity of litter component decomposition under warming gradient with precipitation addition on the Tibetan plateau

Plant and Soil - Interactive effect of warming and precipitation addition on litter decomposition is still scarce. Moreover, nonlinear response of its temperature sensitivity to warming is not...