Geographical distribution and potential distribution prediction of thirteen species of Citrus L. in China

Using DIVA-GIS software to study the spatial accumulation of Citrus species, an important economic crop in China. Draw the distribution maps of Citrus to concerning altitude and vegetation, and use DIVA-GIS' Bioclim ecological model and maximum information entropy model Maxent software to estimate the potential distribution areas of various Citrus species. The results show that the Citrus genus is located in the south of Qinling Mountains, mainly in the southwest of China and the coast of southeastern China. Sichuan and Chongqing are the most densely distributed regions of Citrus. The distribution of Citrus is closely related to the vegetation type and altitude. The vegetation types in the distribution area is evergreen broad-leaved forest, evergreen shrub, deciduous broad-leaved forest, mixed-leaf forest coverage area, deciduous coniferous forest, farmland, trees, other vegetation coverage, and evergreen coniferous forest. The current potential distribution area of Citrus is mainly in Guizhou, Hubei, Hunan, Guangdong, Guangxi, Yunnan, Sichuan, Chongqing, and other provinces and municipalities and their borders, while the potential distribution area in the future moves northward and enter Henan and southern Gansu. At the same time, climate warming changes the distribution of suitable areas of Citrus, which makes the suitable areas of C. sinensis Osbeck, C. reticulata Blanco, and other crops greatly increased. Planning the planting area will effectively improve the yield and quality in the future. Planning presents new challenges.

Geographic distribution and impacts of climate change on the suitable habitats of Glycyrrhiza species in China

Climate change has a major impact on the growth and distribution of plants. Glycyrrhiza is widely used in the treatment of many diseases in China. However, with the overexploitation and the growing demand for medicinal uses in of Glycyrrhiza plants. The investigation of the geographical distribution of Glycyrrhiza plants and the analysis of future climate change are of great significance for the conservation of Glycyrrhiza. In this study, combined with administrative maps of Chinese provinces, the present and future of geographical distribution and richness of six Glycyrrhiza plants in China were studied by using DIVA-GIS and MaxEnt software. A total of 981 herbarium records of these six species of Glycyrrhiza were collected to research. Results show that the change of climate in the future will lead to an increase in habitat suitability for some Glycyrrhiza species as follows: Glycyrrhiza inflata by 61.6%, Glycyrrhiza squamulosa by 47.5%, Glycyrrhiza pallidiflora by 34.0%, Glycyrrhiza yunnanensis by 49.0%, Glycyrrhiza glabra by 51.7%, and Glycyrrhiza aspera by 65.9%. Glycyrrhiza plants have considerable medicinal and economic value, so it is necessary to adopt targeted development and rational management strategies for it.

Guesstimate of thymoquinone diversity in Nigella sativa L. genotypes and elite varieties collected from Indian states using HPTLC technique

Thymoquinone is a valuable metabolite derived from the Nigella sativa L. seeds and has a variety of therapeutic properties. Thymoquinone was estimated using n-hexane:ethyl acetate (8:2, v/v) green solvent system and computed at a wavelength of 254 nm using the high-performance thin-layer chromatography densitometry method in distinct varieties and genotypes congregated from different geographical regions. Genotype Ajmer Nigella-13 has the paramount thymoquinone content (247.60 µg/100 mg seed) followed by Ajmer Nigella 19 (244.5 µg/100 mg seed), while the lowest amount of thymoquinone was recorded in the genotype Ajmer Nigella-6 (42.88 µg/100 mg seed). The hierarchical cluster analysis found that the collected genotypes and elite varieties were classified into four broad clusters, and the identified chemotypes with elevated thymoquinone proportion were positioned in cluster D. Significant genotypic variation in thymoquinone content is available, that can be used in exploiting pharmaceutical applications of N. sativa L. as well as a breeding programme for specific metabolite improvement perspective.

Effects of climate change on the geographical distribution and potential distribution areas of 35 Millettia Species in China

Climate change has an extremely important impact on the geographic distribution of plants. The genus Millettia is an important plant resource in China and is widely used in medicine and ornamental industries. Due to the continuous changes of climate and the development and utilization of plant resources of the genus Millettia, it is of great significance to systematically investigate the geographic distribution of plants of the Millettia and their potential distribution under climate change. DIVA-GIS software was used to analyze 3492 plant specimens of 35 species of genus Millettia in the herbarium, and the ecological geographic distribution and richness of Millettia were analyzed, and the MaxEnt model was used to analyze the current and potential distribution in the future. The results show that the genus Millettia is distributed in 30 provinces in China, among which Yunnan and Guangdong provinces are the most distributed. Our model determines that precipitation in the driest month and annual temperature range are the most important bioclimatic variables. Future climate changes will increase the suitable habitat area of M. congestiflora by 16.75%, but other cliff beans Suitable habitats for vines will decrease significantly: M. cinereal by 47.66%, M. oosperma by 39.16%, M. pulchra by 36.04%, M. oraria by - 29.32%, M. nitida by 22.88%, M. dielsiana by 22.72%, M. sericosema by 19.53%, M. championii by 7.77%, M. pachycarpa by 7.72%, M. speciose by 2.05%, M. reticulata by 1.32%. Therefore, targeted measures should be taken to protect and develop these precious plant resources.

Geographical distribution and predict potential distribution of Angelica L. genus

Climate change is very important for the distribution of plant resources, especially for crops. Angelica plants have a long history of use and significant crop resources in China, whose rhizomes are extensively used in medicine and food. In this paper, 1599 georeferenced herbarium records were analyzed using DIVA-GIS, and the ecological distribution and richness of the current and future distribution simulation were analyzed using the MaxEnt model. The results show that they are from 32 provinces in China. Among these provinces, Sichuan, Gansu, and Yunnan have the largest number of herbariums. According to the MaxEnt model simulation, it is found that the precipitation in the warmest season, annual precipitation, and the driest monthly precipitation are the foremost bioclimatic variables that control the distribution of eight selected Angelica plants (A. biserrata, A. gigas, A. laxifoliata, A. likiangensis, A. longicaudata, A. omeiensis, A. polymorpha, and A. valida). It can be seen from the potential distribution map that the suitable growth areas of A. polymorpha and A. valida have increased, while the suitable growth areas of the six species of Angelica have decreased in varying degrees, 18.24%, 20.01%, 9.91%, 53.16%, 10.06%, and 12.64% respectively. Therefore, it is necessary to protect the Angelica plants.

Geographical distribution and predict potential distribution of Cerasus serrulata

Climate change is closely related to the distribution of plant resources. Cerasus serrulata is an important plant resource in China. The study on the influence of environmental factors on the distribution of suitable areas of C. serrulata is conducive to the protection and development of C. serrulata. In this paper, the distribution information of 238 Chinese Cerasus serrulata plants was processed by DIVA-GIS. The MaxEnt model was used to simulate the current and future distribution, and the ecological distribution and richness of Cerasus were analyzed. The results showed that the Cerasus serrulata was widely distributed in Hebei, Heilongjiang, Shandong, Jiangsu, Zhejiang, Anhui, Jiangxi, Hunan, and Guizhou provinces, mainly in the low and middle elevation areas of 10 to 1200 m. Based on this model, the precipitation of the warmest quarter, the precipitation of the driest month, and the mean temperature of the coldest were the most significant bioclimatic variables affecting the distribution of C. serrulata. In the future, climate change may lead to a slight increase of 2.31% in the area of suitable habitat for Cerasus serrulata, while the optimal habitat will decrease from 20.81 to 14.55%. Therefore, conservation measures should be taken to protect these precious resources.

Assessing the geographical distribution of 76 Dendrobium species and impacts of climate change on their potential suitable distribution area in China

The geographical distribution of plant resources is of great significance for studying the origin, distribution, and evolution of species. Climate and geographical factors help shape the distribution of plant species. Dendrobium is a commonly used traditional medicine and a precious economic crop in China. Owing to the over-exploitation and increasing medicinal demand of Dendrobium species plants, systematic investigation of the geographical distribution of the plants and analysis of their potential distribution under climate change are important for protecting Dendrobium plants. We adopted DIVA-GIS to analyze the georeferenced records of 76 species of the Dendrobium species collected from 2166 herbarium records. We analyzed the eco-geographical distribution and species richness of the genus Dendrobium to simulate the distribution of current and future scenarios using MaxEnt. The results revealed the distribution of Dendrobium in 30 provinces of China, with species abundance in Yunnan, Guangxi, Guangdong, and Hainan. Our model identified the following bioclimatic variables: precipitation in the driest months and the warmest seasons, isothermality, and range of annual temperature. Among them, annual precipitation is the most crucial bioclimatic variable affecting the distribution of 16 selected Dendrobium species. The change of climate in the future will lead to an increase in habitat suitability for some Dendrobium species as follows: D. officinal 2.12%, D. hancockii by 6.00%, D. hercoglossum by 8.25%, D. devonianum by 7.71%, D. henryi by 9.40%, and D. hainanense by 13.70%. By contrast, habitat suitability will dramatically decrease for other Dendrobium species: D. chrysotoxum by 0.89%, D. chrysanthum by 12.68%, D. fimbriatum by 5.07%, D. aduncum by 11.44%, D. densiflorum by 18.47%, D. aphyllum by 8.05%, D. loddigesii by 16.45%, D. nobile by 5.41%, D. falconeri by 8.73%, and D. moniliforme by 10.61%. The reduction of these species will be detrimental to the medicinal and economic value of the genus Dendrobium. Therefore, targeted development and reasonable management strategies should be adopted to conserve these valuable resources.