Genomic footprints of Kam Sweet Rice domestication indicate possible migration routes of the Dong people in China and provide resources for future rice breeding.

The Dong people are one of China's 55 recognized ethnic minorities, but there has been a long-standing debate about their origins. In this study, we performed whole-genome resequencing of Kam Sweet Rice (KSR), a valuable, rare, and ancient rice landrace unique to the Dong people. Through comparative genomic analyses of KSR and other rice landraces from south of the Yangtze River Basin in China, we provide evidence that the ancestors of the Dong people likely originated from the southeast coast of China at least 1000 years ago. Alien introgression and admixture in KSR demonstrated multiple migration events in the history of the Dong people. Genomic footprints of domestication demonstrated characteristics of KSR that arose from artificial selection and geographical adaptation by the Dong people. The key genes GS3, Hd1, and DPS1 (related to agronomic traits) and LTG1 and MYBS3 (related to cold tolerance) were identified as domestication targets, reflecting crop improvement and changes in the geographical environment of the Dong people during migration. A genome-wide association study revealed a candidate yield-associated gene, Os01g0923300, a specific haplotype in KSR that is important for regulating grain number per panicle. RNA-sequencing and quantitative reverse transcription-PCR results showed that this gene was more highly expressed in KSR than in ancestral populations, indicating that it may have great value in increasing yield potential in other rice accessions. In summary, our work develops a novel approach for studying human civilization and migration patterns and provides valuable genomic datasets and resources for future breeding of high-yield and climate-resilient rice varieties.

Traditional agricultural management of Kam Sweet Rice (Oryza sativa L.) in southeast Guizhou Province, China.

BACKGROUND: The Dong people mainly live in Hunan, Guangxi and Guizhou provinces, China, with a long history of glutinous rice cultivation, among which Kam Sweet Rice (KSR) is a group of rice landraces that has been domesticated for thousands of years by the Dong people. The core distribution area of KSR is Liping, Congjiang and Rongjiang County of southeast, Guizhou Province. Paddy fields, forests, livestock and cottages have formed a special artificial wetland ecosystem in local area, and the Dong people have also formed a set of traditional farming systems of KSR for variety breeding, field management, and soil and water conservation. However, this traditional agricultural management has not been reported at multiple levels based on landraces, species and ecosystems. METHODS: Fieldwork was conducted in ten villages in southeast Guizhou from 2019 to 2021. A total of 229 informants were interviewed from the villages. Semi-structured and key informant interviews were administered to collect ethnoecological data on the characteristics and traditional utilization of KSR, traditional farming systems and agricultural management of the Dong people. RESULTS: (1): A total of 57 KSR landraces were recorded as used by the Dong people in southeast Guizhou. We analyzed the cultural importance index (CII) of all KSRs. KSR with high CII often has a pleasant taste, special biological characteristics of cold resistance, disease and insect resistance and high utilization in the traditional culture of Dong people. (2) There is a clear division of labor between men and women in the breeding, seed retention, field management and grain storage management of different landraces of KSR in Dong communities. In order to resist natural disasters and insect pests, the cultivation of KSR is usually managed by multi-variety mixed planting. These agricultural management modes are the result of Dong people's understanding and adaptation to the local natural geographical environment, as well as the experience and wisdom crystallization of Dong people's long-term practice. (3) The traditional farmland of Dong People is a typical artificial wetland ecosystem that is planted with mixed KSR landraces with rich traditional wisdom. In addition, the economic benefit of the rice-fish-duck symbiotic system was 3.07 times that of hybrid rice alone; therefore, the rice-fish-duck system not only has the function of maintaining soil, water and ecological balance but also improves the income of Dong people. CONCLUSION: KSR is a special kind of rice that has been domesticated and cultivated by Dong people for thousands of years. Dong people have also formed traditional agriculture dominated by KSR cultivation. The traditional agricultural management of Dong people provides suitable habitats for flora and fauna with biodiversity protection, and convenient conditions for rational utilization and distribution of water resources were also provided. This traditional management mode is of great significance for environmental protection, climate change response, community resource management, sustainable utilization and agricultural transformation in modern society. Therefore, we call for interdisciplinary research in natural and social sciences, in-depth study of the ecological culture of ethnic areas, and sort out treasures conducive to the development of all mankind.

In situ conservation of traditional vegetable diversity in Wa homegardens in southwestern Yunnan, China.

BACKGROUND: Homegardens are in situ conservation sources of germplasm diversity for overcoming homogenous germplasm problems in industrial agricultural systems. The Wa people constitute a long-dwelling ethnic group mainly in southwestern Yunnan with a unique culture and rich knowledge of traditional vegetables. We hypothesized that traditional vegetable varieties are well conserved in Wa homegardens because Wa culture promotes the preservation of traditional vegetables. We surveyed vegetable varieties and the practices that are involved in the conservation of traditional vegetables in Wa homegardens, which could form the basis for in situ conservation. METHODS: The methods were used including questionnaires and semi-structured interviews. Sixty homegardens were surveyed through purposive sampling in 6 Wa villages. We documented ethnobotanical information about vegetables in homegardens. Plant species were identified according to the Flora of China. And thematic analyses were conducted for in-depth interviews to identify the conservation factors for traditional vegetables. RESULTS: Fifty-two vegetable species belonging to 16 families and 41 genera were recorded from 60 Wa homegardens. Fifty-five traditional vegetable varieties and thirty-six hybrids were recorded. Among all the villages, 23 ± 6 (average ± SD) traditional vegetable varieties per homegarden and 9 ± 3 (average ± SD) introduced varieties per homegarden were recorded. Local seeds were stored in 78% of households, with an additional 9% of households' seed supplies coming from neighbors and relatives; the other 13% of households purchased local seeds from markets. In 83% of families, the female head was mainly responsible for the decision-making concerning traditional vegetables in homegardens; in 10% of families, the male head was responsible for decision-making, and a small percentage (2%) was determined by elderly people. Five percent of families made decisions jointly between male and female household heads. CONCLUSIONS: This study demonstrated that rich traditional germplasm diversity is harbored in Wa homegardens because of the unique culture and traditional knowledge of Wa communities, which are practiced daily with homegrown food plants. Local vegetable seed conservation and sharing systems help maintain germplasm diversity in the Wa community homegardens. Wa homegardens constitute a practical solution for protecting traditional germplasm diversity and maintaining traditional lifestyles.

Skincare plants of the Naxi of NW Yunnan, China.

The Naxi of Northwest Yunnan, China use medicinal plants to treat skin conditions related to traditional lifestyles in extreme environments. However, modernization endangers both the medicinal plants used to treat skin conditions and traditional knowledge. Therefore, investigation and documentation of the medicinal plants used and associated traditional knowledge is necessary. In this study, we conducted an ethnobotanical survey in 12 Naxi communities in Northwest Yunnan. For this purpose, we used semi-structured surveys to interview 840 informants from Naxi communities. We used informant consensus factor and use frequency as quantitative indices to evaluate the importance of medicinal plant species. A total of 161 medicinal plant species belonging to 69 families were documented. The highest informant consensus factor (ICF) values were recorded for skin nourishing (ICF = 0.849), frostbite and chapped skin (ICF = 0.833). These skin treatments are highly related to the environment and lifestyle of Naxi communities. The main active compounds of plants used to treat skin conditions in Naxi communities are known to have skin-treating properties. This study reveals that the skin conditions treated by the Naxi are associated with traditional medicine culture and social economic development. In addition, this study uses ethnobotanical indices to explain how skin condition treatments are linked to the natural environment of Naxi communities.

Changes in traditional ecological knowledge of forage plants in immigrant villages of Ningxia, China.

BACKGROUND: Ecological migration serves as an important measure for poverty eradication as well as for the protection, inheritance, and utilization of traditional ecological knowledge. This study investigated and cataloged the traditional forage plant resources and recorded the associated traditional knowledge of immigrant villages in Hongsibu District of Ningxia, China. The diversity of traditional forage plant resources and the changes in associated traditional ecological knowledge were compared among ecological immigrant villages from different emigration areas, with a hope of providing a reference for forage development, the conservation of wild forage plant resources, and the development of regional animal husbandry. METHODS: From March 2018 to May 2019, a field investigation was conducted in six villages in Ningxia. Through the snowball technique, a total of 315 immigrants were interviewed using various methods, including semistructured interviews and key person interviews, which included opportunities for free listing. The changes in the utilization of traditional forage plants were compared between the ecological migrants and the original inhabitants, and the causes underlying the changes were analyzed. In addition, the major forage plant species in the research area were investigated and evaluated. RESULTS: (1) The six investigated villages reported 224 traditional forage plant species that belong to 42 families and 150 genera. Compared with their original living areas, the number of traditional forage plant species used in the immigrant villages decreased with the increase in the relocation distance. (2) The utilization of traditional forage plants varied among the immigrants who moved to Hongsibu District from forest areas, loess hilly areas, and semiarid desertified areas. The smaller the difference was in ecological environment between the immigration and emigration areas, the more the traditional forage plant knowledge had been retained. (3) The diversity and associated knowledge of traditional forage plants retained by ecological migrants are closely correlated to gender, age, education level, and occupation. CONCLUSION: This study revealed that the diversity of traditional forage plants and associated knowledge retained after migration vary among ecological immigrants from different areas; generally, the immigrants that relocated from a closer place retained more ecological knowledge. In the immigrant villages with significantly different natural resources and a long distance from the migrants' original locations, the diversity of traditional forage plants decreased, and the traditional knowledge about forage plants showed signs of being forgotten and abandoned by the younger generation. Therefore, measures are urgently needed to document and protect the forage plant resources and preserve the traditional knowledge of ecological immigrants.

Plant-Climate Interaction Effects: Changes in the Relative Distribution and Concentration of the Volatile Tea Leaf Metabolome in 2014-2016.

Climatic conditions affect the chemical composition of edible crops, which can impact flavor, nutrition and overall consumer preferences. To understand these effects, we sampled tea (Camellia sinensis (L.) Kuntze) grown in different environmental conditions. Using a target/nontarget data analysis approach, we detected 564 metabolites from tea grown at two elevations in spring and summer over 3 years in two major tea-producing areas of China. Principal component analysis and partial least squares-discriminant analysis show seasonal, elevational, and yearly differences in tea from Yunnan and Fujian provinces. Independent of location, higher concentrations of compounds with aromas characteristic of farmers' perceptions of high-quality tea were found in spring and high elevation teas. Yunnan teas were distinct from Fujian teas, but the effects of elevation and season were different for the two locations. Elevation was the largest source of metabolite variation in Yunnan yet had no effect in Fujian. In contrast seasonal differences were strong in both locations. Importantly, the year-to-year variation in chemistry at both locations emphasizes the importance of doing multi-year studies, and further highlights the challenge farmers face when trying to produce teas with specific flavor/health (metabolite) profiles.

Environmental Factors Variably Impact Tea Secondary Metabolites in the Context of Climate Change.

Climate change is impacting food and beverage crops around the world with implications for environmental and human well-being. While numerous studies have examined climate change effects on crop yields, relatively few studies have examined effects on crop quality (concentrations of nutrients, minerals, and secondary metabolites). This review article employs a culturally relevant beverage crop, tea (Camelia sinensis), as a lens to examine environmental effects linked to climate change on the directionality of crop quality. Our systematic review identified 86 articles as relevant to the review question. Findings provide evidence that shifts in seasonality, water stress, geography, light factors, altitude, herbivory and microbes, temperature, and soil factors that are linked to climate change can result in both increases and decreases up to 50% in secondary metabolites. A gap was found regarding evidence on the direct effects of carbon dioxide on tea quality, highlighting a critical research area for future study. While this systematic review provides evidence that multiple environmental parameters are impacting tea quality, the directionality and magnitude of these impacts is not clear with contradictory evidence between studies likely due to confounding factors including variation in tea variety, cultivar, specific environmental and agricultural management conditions, and differences in research methods. The environmental factors with the most consistent evidence in this systematic review were seasonality and water stress with 14 out of 18 studies (78%) demonstrating a decrease in concentrations of phenolic compounds or their bioactivity with a seasonal shift from the spring and /or first tea harvest to other seasons and seven out of 10 studies (70%) showing an increase in levels of phenolic compounds or their bioactivity with drought stress. Herbivory and soil fertility were two of the variables that showed the greatest contradictory evidence on tea quality. Both herbivory and soil fertility are variables which farmers have the greatest control over, pointing to the importance of agricultural management for climate mitigation and adaptation. The development of evidence-based management strategies and crop breeding programs for resilient cultivars are called for to mitigate climate impacts on crop quality and overall risk in agricultural and food systems.

2014-2016 seasonal rainfall effects on metals in tea (Camelia sinensis (L.) Kuntze).

Plant-climate interactions affect the edible crop composition, impacting flavor, nutrition, and overall consumer liking. In this study, principal components analysis was used to assess the macro- and micronutrient metal concentrations in pre-monsoon (spring), monsoon (summer), and post-monsoon (autumn) tea (Camelia sinensis (L.) Kuntze) from Yunnan Province, China in 2014-2016. Statistical differences were observed (p = 1.35E-24). Fe, Ca, Mg, Mn, Al, and Ba concentrations were higher in June (monsoon) than in March (pre-monsoon) and September (post-monsoon) compared to Pb, K, Cu, Zn, and Na, which were higher in March and September. Although Fe, Ca, Mg, Mn, Al, and Ba concentrations increased during the monsoon season, sensory analysis did not detect metallic taste in either minimally processed or farmer-processed (commercial) teas. This finding shows the seasonal differences in flavor were due to striking differences in organic chemical composition and concentration.

Status and factors influencing on-farm conservation of Kam Sweet Rice (Oryza sativa L.) genetic resources in southeast Guizhou Province, China.

BACKGROUND: Kam Sweet Rice (KSR) is a special kind of rice landrace that has been cultivated for thousands of years in the borders of Guizhou, Hunan, and Guangxi Provinces of China, and is mainly distributed in southeast Guizhou Province of China currently. KSR has many unique qualities, including strong resistance to diseases, pests, and adverse abiotic conditions, difficulty of threshing, and well glutinous features. KSR germplasm resources are an indispensable material and cultural symbol in the production and daily life and customs of the Dong people. Related studies showed that numerous traditional KSR varieties and cultivation area of KSR decreased sharply from the Qing dynasty to 2015, but many KSR varieties are still conserved in Dong villages of southeast Guizhou Province compared to other areas. However, the number of KSR varieties that are conserved on farms in southeast Guizhou Province and factors influencing the erosion and conservation of KSR genetic resources is unclear. Therefore, this study was an on-farm conservation investigation of KSR genetic resource in China's major KSR producing areas-Liping, Congjiang, and Rongjiang counties in Guizhou Province and influencing factors analysis of KSR abandonment and conservation. METHODS: The information of KSR conservation status and variety characteristics, typical villages, Dong's cultural customs, and factors influencing KSR abandonment and conservation was obtained using ethno-biology methods, mainly through field research interviews, including participatory observation, semi-structured interviews, key informant interviews, focus group discussions, and cultural anthropology. The altitude, plant height, awn color and length, hull color, and rice color of 156 KSR accessions in 28 villages were recorded. The variety quantity and cultivation area of KSR were investigated in 33 ethnic villages. Questionnaire surveys were conducted in typical Dong villages to obtain local farmers' attitudes toward cultivation and protection of KSR. We randomly selected 26 farmers from Sizhai village and 30 farmers from Huanggang village and chose 3 social characteristics including age, gender, and education levels of farmers, and adopted the method of face-to-face interviewing to complete the questionnaires. Then, we analyzed the correlation and determined the significance between farmers with different social characteristics and farmers' attitudes to KSR development and protection using SPSS 17.0 software. RESULTS: (1) On-farm conservation status of KSR: a total of 156 KSR varieties were collected from 28 ethnic minority villages from 13 townships (accounting for 21% of three counties) in Liping, Congjiang, and Rongjiang counties. KSR accessions accounted for more than 90% of local rice varieties in each village. According to local farmers, although the quantity of KSR varieties decreased more than 50% in the investigated villages compared to the past 10-20 years, some Dong villages have still cultivated KSR, accounting for more than 50% of the rice field area in 10 villages. This result showed that many KSR varieties are still conserved by in Dong villages, and these KSR varieties have a high genetic diversity of phenotypes. (2) Typical villages investigation: the cultivation area of KSR in Congjiang was the highest, 6.7 times larger than Liping and eight times larger than Rongjiang. In addition, the cultivation area of KSR in Dong villages was larger than that in other ethnic villages, and villages that had a higher planting area of KSR had more KSR accessions. (3) Farmers' attitude toward the development and conservation of KSR: Dong farmers hold the negative attitudes concerning the development of KSR resources, but they thought it is necessary to protect KSR landraces. Especially, a high level of education and female, young, and old farmers played more important roles in the cultivation and protection of KSR. CONCLUSIONS: Until now, some Dong ethnic villages have still cultivated KSR for thousands of years in Qiandongnan area, although the number of varieties and the planting area of KSR have been greatly reduced. In addition, ethnic traditional culture and social customs were the main influencing factors of KSR conservation; economic, management, and policy factors were the main influencing factors of KSR abandonment. Through the analysis of the correlation between farmers with different social characteristics and their attitudes toward the cultivation, reasons for conservation and abandonment, development tendency, and protection of KSR, we found that a high level of education and female, young, and old farmers play more important role in the cultivation and protection of KSR. Therefore, in order to promote the protection and sustainable utilization of KSR, it is necessary to build on-farm conservation of KSR and improve the position of female farmers and the education level of young people, and encourage the old people to educate the middle-aged to conserve and protect KSR as well as Dong's traditional culture and social customs. This study is of great significance to promote better protection and optimal utilization of KSR and enable the public, government, and related researchers pay more attention to conserving ethnic traditional cultures.

Striking changes in tea metabolites due to elevational effects.

Climate effects on crop quality at the molecular level are not well-understood. Gas and liquid chromatography-mass spectrometry were used to measure changes of hundreds of compounds in tea at different elevations in Yunnan Province, China. Some increased in concentration while others decreased by 100's of percent. Orthogonal projection to latent structures-discriminant analysis revealed compounds exhibiting analgesic, antianxiety, antibacterial, anticancer, antidepressant, antifungal, anti-inflammatory, antioxidant, anti-stress, and cardioprotective properties statistically (p = 0.003) differentiated high from low elevation tea. Also, sweet, floral, honey-like notes were higher in concentration in the former while the latter displayed grassy, hay-like aroma. In addition, multivariate analysis of variance showed low elevation tea had statistically (p = 0.0062) higher concentrations of caffeine, epicatechin gallate, gallocatechin, and catechin; all bitter compounds. Although volatiles represent a small fraction of the total mass, this is the first comprehensive report illustrating how normal variations in temperature, 5 °C, due to elevational effects impact tea quality.

Genome-wide association study of rice grain width variation.

Seed size is variable within many plant species, and understanding the underlying genetic factors can provide insights into mechanisms of local environmental adaptation. Here we make use of the abundant genomic and germplasm resources available for rice (Oryza sativa) to perform a large-scale genome-wide association study (GWAS) of grain width. Grain width varies widely within the crop and is also known to show climate-associated variation across populations of its wild progenitor. Using a filtered dataset of >1.9 million genome-wide SNPs in a sample of 570 cultivated and wild rice accessions, we performed GWAS with two complementary models, GLM and MLM. The models yielded 10 and 33 significant associations, respectively, and jointly yielded seven candidate locus regions, two of which have been previously identified. Analyses of nucleotide diversity and haplotype distributions at these loci revealed signatures of selection and patterns consistent with adaptive introgression of grain width alleles across rice variety groups. The results provide a 50% increase in the total number of rice grain width loci mapped to date and support a polygenic model whereby grain width is shaped by gene-by-environment interactions. These loci can potentially serve as candidates for studies of adaptive seed size variation in wild grass species.

Agrobiodiversity and in situ conservation in ethnic minority communities of Xishuangbanna in Yunnan Province, Southwest China.

BACKGROUND: Xishuangbanna of Yunnan Province, southwest of China belongs to a global biodiversity and cultural hotspot. Agrobiodiversity plays an essential role in local livelihoods and traditional culture in the region. However, preliminary studies suggest that diversity of crop plants and livestock species is declining. We hypothesized that agrobiodiversity and traditional means of preserving agrobiodiversity are threatened because of changes in government policy in favor of commercial plantations, land use change and changes in traditional agricultural practices. We investigated whether or not agrobiodiversity was declining, the specific causes, and signs of active biodiversity conservation practices in ethnic minority communities of Xishuangbanna which could form the basis for extensive in situ conservation programmes. METHODS: A series of field studies to document trends in agrobiodiversity were conducted in different ethnic minority communities in Menghai County, Mengla County and Jinghong City of Xishuangbanna of Yunnan Province, southwest of China between July 2015 and February 2016. Data was obtained through the use of semi-structured questionnaires, field observation and participatory rural appraisal (PRA) tools. A total of 360 ethnic households provided information on current status, functions, characteristics, changes, and threatened factors of farming crop and livestock resources. Some measures for in situ conservation of agricultural biological resources were also researched using PRA methods. RESULTS: Two hundred twenty-six crop varieties belonging to 31 families, 71 genera and 101 species were identified in Xishuangbanna, which included 83 vegetable crops, 77 food crops, 24 spice crops, 22 fruit crops, 13 cash crops, 6 oil crops, and 1 cloth crop, respectively. There were 15 livestock varieties, belonging to 6 major species: cattle, pigs, goats, chickens, ducks, and geese. Different crop and livestock resources had their own characteristics, functions and threatened factors. Since 2002, agroecosystem, crop diversity and livestock diversity have declined greatly over the Xishuangbanna region as a whole under implementation of the Sloping Land Conversion Program (SLCP). Swidden agriculture was completely eliminated under this program and gradually replaced by large land areas devoted to rubber, tea and banana plantations. Villager numbers engaging in farming production and population of crops and livestock were greatly decreased, particularly in terms of production of local traditional varieties. However, some in situ conservation measures such as seeds preservation, planting of traditional crops and raising livestock have played an important role in local agrobiodiversity conservation. CONCLUSION: Abundant agricultural resources and agrobiodiversity are critical to the local livelihood and maintenance of traditional culture in Xishuangbanna. However, agrobiodiversity and related traditional culture have been greatly impacted by implementation of the SLCP since 2002. Therefore, in future conservation of agrobiodiversity, incorporating some sustainable protection measures based in local communities such as convening seed exchange fairs, conserving traditional varieties in permanent plots, making a visual documentary of indigenous cultivation, and providing traditional agricultural products to tourists should be carefully considered and adopted.

Four New Diterpene Glucosides from Perovskia atriplicifolia.

Four new diterpene glucosides, namely perovskiaditerpenosides A - D (1 - 4), were isolated from the BuOH extract of Perovskia atriplicifolia. Their structures were well elucidated by chemical methods and comprehensive spectroscopic analyses including MS, IR, and NMR (1D and 2D). The newly isolated compounds were screened for their cytotoxic activity against HepG2, NB4, HeLa, K562, MCF7, PC3, and HL60. The obtained results indicated that the new compounds possessed considerable cytotoxic activity.

Influence of ethnic traditional cultures on genetic diversity of rice landraces under on-farm conservation in southwest China.

BACKGROUND: Crop genetic resources are important components of biodiversity. However, with the large-scale promotion of mono-cropping, genetic diversity has largely been lost. Ex-situ conservation approaches were widely used to protect traditional crop varieties worldwide. However, this method fails to maintain the dynamic evolutionary processes of crop genetic resources in their original habitats, leading to genetic diversity reduction and even loss of the capacity of resistance to new diseases and pests. Therefore, on-farm conservation has been considered a crucial complement to ex-situ conservation. This study aimed at clarifying the genetic diversity differences between ex-situ conservation and on-farm conservation and to exploring the influence of traditional cultures on genetic diversity of rice landraces under on-farm conservation. METHODS: The conservation status of rice landrace varieties, including Indica and Japonica, non-glutinous rice (Oryza sativa) and glutinous rice (Oryza sativa var. glutinosa Matsum), was obtained through ethno-biology investigation method in 12 villages of ethnic groups from Guizhou, Yunnan and Guangxi provinces of China. The genetic diversity between 24 pairs of the same rice landraces from different times were compared using simple sequence repeat (SSR) molecular markers technology. The landrace paris studied were collected in 1980 and maintained ex-situ, while 2014 samples were collected on-farm in southwest of China. RESULTS: The results showed that many varieties of rice landraces have been preserved on-farm by local farmers for hundreds or thousands of years. The number of alleles (Na), effective number of alleles (Ne), Nei genetic diversity index (He) and Shannon information index (I) of rice landraces were significantly higher by 12.3-30.4 % under on-farm conservation than under ex-situ conservation. Compared with the ex-situ conservation approach, rice landraces under on-farm conservation programs had more alleles and higher genetic diversity. In every site we investigated, ethnic traditional cultures play a positive influence on rice landrace variety diversity and genetic diversity. CONCLUSION: Most China's rice landraces were conserved in the ethnic areas of southwest China. On-farm conservation can effectively promote the allelic variation and increase the genetic diversity of rice landraces over the past 35 years. Moreover, ethnic traditional culture practices are a crucial foundation to increase genetic diversity of rice landraces and implement on-farm conservation.

Patterns and structures of land use change in the Three Rivers Headwaters Region of China.

Located in Qinghai Province of China, the Three Rivers Headwaters Region is the source region of the Yangtze, Yellow and Lantsang Rivers, and plays an important role in biodiversity conservation and regulating water supply. Despite many efforts on land use change in Qinghai, knowledge of the spatial variation of land use change is still lacking. This study examines the patterns of land use change across various watersheds, prefectures and the temple surroundings. Remote sensing images of 1987, 1997 and 2007 were analyzed to derive land use distributions; patterns and structures of the landscape were then quantified with landscape metrics. The results illustrated that the Yangtze River headwater region had more diverse and more evenly distributed landscape, while the Lantsang and the Yellow headwater regions showed a decline in landscape diversity. Comparison of the land use patterns of four prefectures revealed that Yushu Prefecture experienced an increase in landscape diversity from 1987 to 2007 while the land use patches in Guoluo Prefecture exhibited more aggregated patterns than other prefectures. Analysis of the spatial variations of land use change in the temple surroundings illustrated that 19.7% and 35.9% of the temples in Guoluo and Yushu Prefectures, respectively, encountered land use change for their immediate areas within 2 km. Comparison of the surroundings of temples and human settlements found that land use change was not evenly distributed, and that greater land use change had occurred for the surroundings of human settlements. Such findings provided insights into the spatial variation of land use change in the Three Rivers Headwaters Region.

Effects of extreme climate events on tea (Camellia sinensis) functional quality validate indigenous farmer knowledge and sensory preferences in tropical China.

Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world's most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in a major tea producing area of China during an extreme drought through the onset of the East Asian Monsoon in order to capture effects of extreme climate events that are likely to become more frequent with climate change. Compared to the spring drought, tea growth during the monsoon period was up to 50% higher. Concurrently, concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower during the monsoon while total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in concentrations of tea secondary metabolites was accompanied by reduced farmer preference on the basis of sensory characteristics as well as a decline of up to 50% in household income from tea sales. Farmer surveys indicate a high degree of agreement regarding climate patterns and the effects of precipitation on tea yields and quality. Extrapolating findings from this seasonal study to long-term climate scenario projections suggests that farmers and consumers face variable implications with forecasted precipitation scenarios and calls for research on management practices to facilitate climate adaptation for sustainable crop production.

Effects of Traditional Chinese Medicinal Plants on Anti-insulin Resistance Bioactivity of DXMS-Induced Insulin Resistant HepG2 Cells.

ABSTRACT: Medicinal plants have a long history of use in China to treat diabetic symptoms. Ancient Chinese medical manuscripts and ethnobotanical surveys document plant remedies that continue to be actively used in China for the treatment of diabetic symptoms. Based on a systematic ancient Chinese medical manuscripts review in combination with ethnobotanical survey, 16 medicinal plants for the traditional treatment of diabetic symptoms were identified for the evaluation of anti-insulin resistance bioactivity. The biological activity of 16 medicinal plants was tested on dexamethasone (DXMS)-induced insulin resistant HepG2 cells. The result shows that 11 of the 16 medicinal plants enhanced glucose uptake of DXMS-induced insulin resistant HepG2 cells, thereby demonstrating their ability to increase insulin sensitivity, other five medicinal plants including Astragalus membranaceus were found ineffective. The study shows that ancient Chinese medical manuscripts and ethnobotanical surveys on plants for the prevention and treatment of diabetic symptoms provide a promising knowledge base for drug discovery to mitigate the global diabetes epidemic.

Comparative homegarden medical ethnobotany of Naxi healers and farmers in Northwestern Yunnan, China.

BACKGROUND: Homegardens are ecologically and culturally important systems for cultivating medicinal plants for wellbeing by healers and farmers in Naxi communities of the Sino Himalayan region. The cultivation of medicinal plants in Naxi communities and associated ethnomedical knowledge base for maintaining and utilizing these resources is at risk with expanded commercialization of natural resources, development policies and rapid socio-economic change in China. Research is needed to understand the medicinal plant species maintained in Naxi homegardens, their use and contribution to community wellbeing, and how these practices and knowledge base varies between Naxi healers and farmers in order to develop plans for biodiversity conservation and preservation of ethnomedical practices. The main objective of this study is to document and compare medicinal plant species in Naxi homegardens and associated ethnomedical knowledge between Naxi healers and farmers. METHODS: Ethnobotanical homegarden surveys were conducted with three Naxi healers and 28 farmer households in two Naxi communities in Lijiang Prefecture in Northwest Yunnan Province of China. Surveys included inventories of medicinal plants in homegardens and semi-structured interviews with homegarden managers to document traditional medicinal uses of inventoried plants. Inventoried plants were classified into 13 'usage categories' of medical condition groupings that impact a system of the body. Finally, plant species richness was calculated for each homegarden and species richness was compared between healers and farmers as well as between study sites using a Least Square Means Tukey HSD function. RESULTS: Ethnobotanical surveys at the study sites found that 13% of households rely exclusively on traditional Naxi medicine, 26% exclusively use Western medicine and 61% use a combination of traditional Naxi and Western medicine. A total of 106 medicinal plants were inventoried in Naxi homegardens representing 50 botanical families. Over 85% of inventoried medicinal plants were herbaceous. The most represented families were Asteraceae (12.8%), Ranunculaceae (8.3%), Apiaceae (8.3%), and Polygonaceae (7.3%). The primary medical functions of inventoried plants were to treat inflammation (73 species), circulatory system disorders (62), nervous system disorders (41), detoxification (39), digestive system disorders (33), muscular-skeletal system disorders (26), genitourinary system disorders (26), skin conditions (23), respiratory systems disorders (22), and cold and flu (20). Local herbal experts maintained greater medicinal plant species richness in their homegardens compared to local farmers as well as had greater knowledge of medicinal functions of plants. Healers maintained medicinal plants primarily for healing while farmer households maintained approximately 90% of the medicinal plants in their homegardens for commercialization and the remaining for household healthcare. CONCLUSIONS: This study highlights the importance of biodiversity and traditional ecological and medical knowledge for human wellbeing and livelihoods in Naxi communities. Conservation efforts and policies are necessary to preserve the ecological and cultural base that maintains medicinal plant use by both healers and farmers in Naxi homegardens of the Sino Himalayan region.

[Spectral reflectance characteristics of dominant plant species at different eco-restoring stages in the semi-arid grassland].

The objective of the research is to apply hyperspectral technique into eco-restoring monitoring. Through the ASD Fields HH portable field spectrometer, the hyperspectral data of dominant plant species in vegetation at different eco-restoring stages in semi-arid grassland in Helin County, Inner Mongolia were collected. The original spectrum reflected data were pretreated by wavelet threshold denoising through ViewSpecPro software before analysis. Using the first derivative spectra between 660 and 800 nm, and the methods of detrended canonical correspondence analysis (DCCA) by Canoco 4. 5 software, the canopy hyperspectral datum of 6 dominant plant species was calculated. The results indicated that the dominant plant species at early succession stage were Setaria viridis and Caragana microphylia, at 5 years eco-restoring stage they were Salsola collina and Caragana microphylia and at late succession stage they were Pinus sylvestnis var. mongolica and Salsola collina, same as field survey. The graph of DCCA indicated that the influential bands of dominant species canopy at early eco-succession stage were short bands, with a large variation among species, the influential bands at 5 years eco-restoring stage were near infrared bands between 1 000 and 1 050 nm, and that at late stage were near infrared bands of 1 040-1 075 nm. The DCCA also showed obviously differences in canopy spectrum among 6 dominant species, and obviously differences among 3 eco-restoring stages.