Eco-geographical Regions Research Articles

Coordination between leaf pH and other leaf traits are divergent among life-forms and eco-geographic regions in plants of northern China

Abstract As a key functional trait affecting many physiological processes, leaf pH is closely related to other leaf traits at local scale. Nevertheless, whether and how leaf pH is linked with other leaf functional traits across geographic scales remains unclear. A field survey in northern China was conducted to investigate the relationships between leaf pH and some key leaf structural (specific leaf area, SLA; leaf dry matter content, LDMC) and chemical traits (elemental concentrations; total dissolved solids, TDS; practical salinity), as well as the effects of environmental factors on these relationships. Our results showed that the trait coordination may vary in degree or direction across eco-geographic regions (arid vs non-arid regions) and life-forms (woody vs herbaceous plants). Generally, leaf pH was negatively related to SLA, but positively related to TDS and salinity. However, leaf pH and LDMC were negatively correlated in arid regions but positively correlated in non-arid regions; leaf pH covaried with N (similarly, with Ca, Mg, and Na) in the same direction for both herbaceous and woody plants in arid regions, but not in non-arid regions. The relationships of leaf pH with leaf Ca and Fe concentrations were mainly influenced by climatic factors, while those with leaf P, Ca and Mn concentrations mostly affected by soil factors. Our findings highlight the divergent coordination between leaf pH and other leaf traits across life-forms and eco-geographic regions, and may shed light on the in-depth understanding of the role of acid-base balance in plant eco-physiological processes and ecological adaptation over biogeographic scales.

Tracing post-domestication historical events and screening pre-breeding germplasm from large gene pools in wheat in the absence of phenotype data.

Wheat, particularly common wheat (Triticum aestivum L.), is a major crop accounting for 25% of the world cereal production and thriving indiverse ecogeographic regions. Its adaptation to diverse environments arises from its three distinct genomes adapted to different environments and post-domestication anthropogenic interventions. In search of key genomic regions revealing historic events and breeding significance to common wheat, we performed genome scan and genome-environment association (GEA) analyses using high-marker density genotype datasets. Whole-genome scans revealed highly differentiated regions on chromosomes 2A, 3B, and 4A. In-depth analyses corroborated our previous prediction of the 4A differentiated region signifying the separation between Spelt/Macha and other wheat types. Individual chromosome scans captured key introgressions, includingone from T. timopheevii and one fromThinopyrum ponticum on 2B and 3D, respectively, as well as known genes such as Vrn-A1 on 5A. GEA highlighted loci linked to latitude-induced environmental variations, influencing traits such as photoperiodism and responses to abiotic stress. Variation at theVrn-A1 locus on 5A assigned accessions to two haplotypes (6% and 94%). Further analysis on Vrn-A1 coding gene revealed four subgroups of the major haplotype, while the minor haplotype remained undifferentiated. Analyses at differentiated loci mostly dichotomized the population, illustrating the possibility of isolating pre-breeding materials with desirable traits from large gene pools in the absence of phenotype data. Given the current availability of broad genetic data, the genome-scan-GEA hybrid can be anefficient and cost-effective approach for pinpointing environmentally resilient pre-breeding germplasm from vast gene pools, including gene banks regardless of trait characterization.

Identifying the dominant compound events and their impacts on vegetation growth in China

Terrestrial vegetation plays a vital role in global carbon recycling, but it is also affected by compound events (CEs); however, little is known about the impacts of these CEs on vegetation in terms of their occurrence and magnitude. Using meteorological observations and vegetation indices (leaf area index (LAI), gross primary productivity (GPP), and net primary productivity (NPP)) from 1981 to 2020, we explored the occurrence of 13 CEs types and identified the dominant CEs types across different eco-geographical regions of China, and quantified the response of various vegetation types to dominant CEs. We found that CEs of extreme hot-dry, extreme hot-dry-high fire weather, dry-high fire weather, and high fire weather-strong wind were the dominant types of compound events during the growing season in China, and their hazards increased at a rate of >0.1HI/10a during 1981–2020. We further detected that more than 60% of the total vegetation areas showed a strong negative correlation with compound extreme hot-dry-high fire weather-strong wind events, which was relatively higher than compound extreme hot-dry events. The response of vegetation to compound events varied at the national scale, which was related to the vegetation type, dominant compound event type, and local natural conditions. This study highlights the benefits of a multivariate perspective on compound events and reveals the regional differences in the response of vegetation to compound events, which can provide initial guidance to assess the regional compound event risk of vegetation against the background of carbon neutrality by 2060.

Genetic Divergence Studies in Cucumber (Cucumis sativus L.) Genotypes for Yield and Quality

Background: In an effort to identify divergent superior parents for hybridization programme, a study to examine the genetic divergence in yield and quality traits was conducted. Methods: Thirty two cucumber genotypes were collected from different states of India and were evaluated for yield and quality characters at Bhubaneswar, Odisha during Rabi season of 2019. Result: The genetic diversity of 32 cucumber genotypes was evaluated using a randomized block design. The Mahalanobis D2 statistic revealed the presence of substantial genetic diversity among the 32 genotypes examined. In a study of 32 cucumber genotypes, clustering based on interactions in genetic distances revealed substantial genetic divergence among the groups. Genotypes from different ecogeographic regions were distributed into distinct clusters in an apparently random fashion, suggesting that there was no correlation between geographic distribution and genetic diversity. Cluster I included the most unique genotypes, suggesting that it was a major contributor to the overall genetic divergence among the five groups. Results showed that Clusters II, IV and V were all monogenomic. Cluster II, IV and V had the smallest intra-cluster distances (0.00), whereas cluster I had the largest (45.08). There was the greatest genetic distance (133.68) between cluster’s I and V, suggesting that cluster V could be used in a future hybridization study. Clusters IV, V and III had the highest mean values of the five clusters for many of the characteristics. According to the ranking of D2 value, the contribution of fruit yield per vine (16.50%) towards genetic divergence was highest. Therefore, phenotypic selection could be used to further enhance this trait.

GENETIC DIVERSITY ANALYSIS IN SOME LOW LAND RICE LANDRACES USING AGRO-MORPHOLOGICAL TRAITS

Forty four landraces of lowland rice were assessed for genetic diversity using D2 statistics based on various grain yielding parameters. Significant variability was found among the traits studied. Eight diverse clusters were made to set them into groups. The pattern of distribution of genotypes from different eco geographic regions into various clusters was at random indicating that geographical diversity and genetic diversity were not related. The maximum inter-cluster distance was observed between cluster III and IV (1033.15), followed by clusters II and VIII (935.07). Maximum intra-cluster distance was observed in cluster IV (731.01). Divergence analysis revealed significant variation among the parental lines for all the agro-morphological traits. Cluster analysis showed that superior cultivars like ‘Kanakchur’ from cluster IV; cv. ‘FR13A’, ‘Jaladhi2’, ‘Matla’ and ‘Purni’ from cluster III; cv. ‘Latisail’, ‘Pimpu Dibasa’, ‘Jeeringa Samba’ and ‘Shib Chato’ from cluster II; and cv. ‘ARC11210’, ‘Kumar Gore’, ‘NC678’, ‘Sada Mota’ and ‘Kantaranga’ from cluster VI may be taken in hybridization program, based on the genetic distance, relative contribution of characters towards total divergence and yield potential of genotypes. The characters viz., days to 50% flowering, plant height, panicle weight and number of grains panicle-1contributed maximum towards the divergence among genotypes taken for this study. So, allelic diversity among the genotypes and the concerned traits taken for this experiment should be taken into consideration while framing a rice breeding programme.

Hydrological impacts of vegetation cover change in China through terrestrial moisture recycling

Terrestrial moisture recycling (TMR), characterized by a continuous process comprising green water flow (i.e., terrestrial evaporation), atmospheric transport, and terrestrial precipitation, functions as a nexus connecting hydrosphere, atmosphere, biosphere, and anthroposphere. During this process, land cover changes that impact green water flow can modify regional and remote precipitation patterns, potentially yielding far-reaching effects on water resources and human livelihoods. However, the comprehensive patterns of moisture recycling and transfer across eco-geographical regions in China, and their connection with various land cover types and vegetation transitions, remain insufficiently evaluated. This study employed an atmospheric moisture tracking model to quantify China's TMR pattern and evaluate the hydrological impacts of vegetation cover changes in China's ecosystems through TMR. The results demonstrate a significant moisture recycling ratio (52.4 %) and a considerable recycled volume (1.9 trillion m3/a) over China, characterized by pronounced moisture transfer from south to north and southwest to northeast. Among various land cover types, grasslands, croplands, and forests play pivotal supportive roles in China's TMR, contributing 738.8, 470.0, and 450.0 billion m3/a of precipitation in China, respectively. Moreover, the potential transition of vegetation between forest and cropland exerts the most significant and extensive impact on China's hydrological cycle. The conversion from forest to cropland leads to a total decrease of 44.7 billion m3/a in precipitation, whereas reforestation from cropland corresponds to a precipitation increase of 74.9 billion m3/a. This study provides a quantitative approach to comprehending the TMR pattern and its relationship with ecosystems, substantiating the significance of a comprehensive water management framework that considers the contribution of atmospheric moisture recycling and the impact of vegetation cover change.

Molecular characterization of oats (Avena sativa L.) diversity: Implications for dual-purpose breeding

Oat (Avena sativa L.) is one of the world's healthiest and gluten-free grains that are packed with essential vitamins, minerals, fiber, and antioxidants. It is also one of the most important cereal fodder crops. The present study was conducted from 2016 to 2018 and morphological and molecular diversity was analyzed for dual-purpose oat based on ten fodder and eight grain traits among 96 oats accessions including four wild accessions (A. vavilioviana, Guiena oats, A. maroccana and A. sterilis) collected from various eco-geographical regions of India. Thirty-one out of one hundred seventy (18%) simple sequence repeats (SSR) markers detected polymorphism among the 96 oat accessions with average polymorphic information content (PIC) of 0.47. A total of 100 alleles were detected with an average of 3.2 alleles per primer. The molecular diversity analysis grouped all the 96 germplasm lines into two major clusters, ?A? and ?B?. The similarity coefficients ranged from 0.37 to 1. The genotypic pairs viz; UPO 276: SKO 315 (46%); SKO 314: OL-125 (46%); SKO 314: OS 363 (49%); SKO 314: UPO 032 (49%) exhibited least genetic similarity and these pairs can be potentially used as parents to conduct various mapping studies and further contributing to the oat breeding community. Moreover, 6 accessions (JHO-2001-1, JHO-99-2, OL 1635, SKO 27, UPO 093 and OS329) had been identified which were superior to OL-10 (best check in the northwest India) for fodder as well as grain yield. This study showed the opportunity of utilizing SSR markers with morphological characteristics to breed for dual purpose oats.

Exploring the relative importance of preseason climatic drivers on spring phenology dynamics in the Greater Khingan Mountains, Northeast China

AbstractExploring spring phenology dynamics driven by climate change is crucial for investigating land–climate feedback. However, a thorough assessment of the influence of climatic drivers on spring phenology remains lacking. Here, we investigated spatiotemporal variations at the start of the growing season (SOS) in the Greater Khingan Mountains, Northeast China, during 1982–2015 using the normalized difference vegetation index third‐generation dataset from Global Inventory Modelling and Mapping Studies. To investigate the influence of preseason climatic factors on the SOS, partial correlation analysis was employed to assess correlations as well as to identify dominant regional drivers. Overall, the SOS dates in the study area showed obvious regional characteristics from 1982 to 2015, with a gradual delay from north to south, with more than 90% of the SOS dates occurring from Julian days 125–140. Advancement trends were observed in all ecogeographical regions, thus accounting for 94.6% of the entire research area, with an average of 7.14 days in advance. The partial correlation analysis revealed spring phenology was most significantly influenced by preseason temperature, and temperature promoted the advancement of SOS in almost the entire study area, but for semi‐humid/semi‐arid regions, the effects of total precipitation was greatest. Interestingly, preseason radiation also dominated earlier SOS dates by a few pixels, albeit in a fragmented distribution. Generally, the preseason temperature had a prominent influence on the SOS dates across all ecogeographical regions, whereas the roles of preseason precipitation and radiation varied by region. In addition to analysing a single climatic factor, our study aimed to analyse the comprehensive impacts of climatic factors on spring phenological processes, with a focus on the composite effects, helping us to improve predictions of spring phenology and provide a better understanding of land–climate interactions.

Salt Stress Responses in Early Seedling Growth Characteristics of Blackgram [Vigna mungo (L.) Hepper] Genotypes

In view of increasing salinity and intrusion of salt water into the cultivable land area under coastal saline region, germination and crop establishment is a major problem that influence on decrease in the production and productivity of blackgram. Hence, screening of 101 genotypes under different salt concentrations for growth characters paves way to identify the saline resistant genotypes. The upshot of saline stress on seedling growth characters of 101 genotypes which are collected from different eco geographical regions subjected to Half strength Hoagland and Arnon’s solution (T1), Half strength Hoagland Arnon’s solution +NaCl treatment @100mM, 150mM, 200mM and 250mM concentration @7th, 10th, 13th, 16th days (T2) respectively and Half strength Hoagland and Arnon’s solution (control) (T3) during January 2022. Highly significant variation exhibited among the various genotypes for different seedling growth characters viz., leaf area per plant, total number of leaves per plant, dry weight of leaves per plant, dry weight of shoot per plant, dry weight of roots per plant and dry weight of the whole plant. Salinity has the adverse effect on the growth characters. Among the genotypes studied, AUB-08-33(G81) and CBG-09-08(G18) showed maximum mean values under different NaCl concentrations (T2), recommended as donor parent for hybridization as well as candidate genotype in crop improvement for saline soil.

Spatial and Temporal Evolution Characteristics of Water Conservation in the Three-Rivers Headwater Region and the Driving Factors over the Past 30 Years

The Three-Rivers Headwater Region (TRHR), located in the hinterland of the Tibetan Plateau, serves as the “Water Tower of China”, providing vital water conservation (WC) services. Understanding the variations in WC is crucial for locally tailored efforts to adapt to climate change. This study improves the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) water yield model by integrating long-term time series of vegetation data, emphasizing the role of interannual vegetation variation. This study also analyzes the influences of various factors on WC variations. The results show a significant increase in WC from 1991 to 2020 (1.4 mm/yr, p < 0.05), with 78.17% of the TRHR showing improvement. Precipitation is the primary factor driving the interannual variations in WC. Moreover, distinct interactions play dominant roles in WC across different eco-geographical regions. In the north-central and western areas, the interaction between annual precipitation and potential evapotranspiration has the highest influence. Conversely, the interaction between annual precipitation and vegetation has the greatest impact in the eastern and central-southern areas. This study provides valuable insights into the complex interactions between the land and atmosphere of the TRHR, which are crucial for enhancing the stability of the ecosystem.

Pleistocene-dated genomic divergence of avocado trees supports cryptic diversity in the Colombian germplasm

Genomic characterization of ex situ plant collections optimizes the utilization of genetic resources by identifying redundancies among accessions, capturing cryptic variation, establishing reference collections, and ultimately assisting pre-breeding and breeding efforts. Yet, the integration of evolutionary genomic analyses is often lacking when studying the biodiversity of crop gene pools. Such is the case in the avocado, Persea americana Mill., an iconic American fruit tree crop that has seen an unprecedented expansion worldwide because of its nutritional properties. However, given a very restricted number of commercial clones, avocado plantations are becoming more vulnerable to diseases and climate change. Therefore, exploring new sources of evolutionary novelty and genetic diversity beyond the commercial varieties derived from traditional genetic pools in Mexico and Central America is imperative. To fill this gap, we aimed to characterize the genomic diversity of Colombian avocado trees. Specifically, we constructed reduced representation genomic libraries to genotype by sequencing 144 accessions from the Colombian National genebank and 240 materials from local commercial orchards in the Colombian northwest Andes. We merged the resulting reads with available sequences of reference genotypes from known avocado groups (also named as races), Mexican, Guatemalan, and West Indian, to discover 4931 SNPs. We then analyzed the population structure and phylogenetic diversity, and reconstructed evolutionary scenarios, possibly leading to new genetic groups in Colombian germplasm. We detected demographic stratification despite evidence of intergroup gene flow. Besides the classical three avocado groups, we found an exclusive Colombian group with a possible genetic substructure related to the geographical origin (Andean and Caribbean). Phylogenetic and ABC demographic modeling suggested that the Colombian group evolved in the Pleistocene before human agriculture started, and its closest relative from the three recognized races would be the West Indian group. We conclude that northwest South America offers a cryptic source of allelic novelty capable of boosting avocado pre-breeding strategies to select rootstock candidates well adapted to specific eco-geographical regions in Colombia and abroad.

The ricebean genome provides insight into Vigna genome evolution and facilitates genetic enhancement.

The ricebean genome provides insight into Vigna genome evolution and facilitates genetic enhancement.

Moth bean (Vigna aconitifolia): a minor legume with major potential to address global agricultural challenges.

Moth bean (Vigna aconitifolia) is an orphan legume of Vigna genus, exhibiting wide adaptability and has the potential to grow well in arid and semi-arid areas, predominantly across different eco-geographical regions of Asia, particularly the Indian subcontinent. The inherent adaptive attributes of this crop have made it more tolerant towards a diverse array of abiotic and biotic stresses that commonly restrain yield among other Vigna species. Additionally, the legume is recognized for its superior nutritional quality owing to its high protein content as well as amino acid, mineral and vitamin profile and is utilized as both food and fodder. Moth bean can play a vital role in sustaining food grain production, enhancing nutritional security as well as provide a source of income to resource-poor farmers amid rise in global temperatures and frequent drought occurrences, particularly in rain-fed cropping systems which accounts for about 80% of the world's cultivated land. However, this minor legume has remained underutilized due to over-exploitation of major staple crops. With the exception of a few studies involving conventional breeding techniques, crop improvement in moth bean for traits such as late maturity, indeterminate growth habit, shattering and anti-nutritional factors has not garnered a lot of attention. Recent advances in sequencing technologies, modern breeding approaches and precision phenotyping tools, in combination with the available crop gene pool diversity in gene banks, can accelerate crop improvement in moth bean and lead to the development of improved cultivars. Considering the recent surge in awareness about the development of climate-smart crops for sustainable agricultural future, collective effort towards effective utilization of this hardy, neglected legume is the need of the hour.

ISRAEL ACUTE BEE PARALYSIS VIRUS PREVALENCE IN APIARIES WITH COLONY LOSS IN TÜRKİYE

Honeybees are indispensable pollinator insects for vegetative pollination and biodiversity. Moreover, they serve medicinal importance with products such as honey, propolis, pollen, and royal jelly. Sudden bee deaths and colony collapse disorder (CCD) threaten the sustainability of colony health. Honeybee viruses, parasites, and pathogens trigger colony losses and CCD. This study investigated the presence and prevalence of Israeli acute bee paralysis virus (IAPV) in apiaries with sudden bee deaths, colony losses, and CCD-like problems in 16 provinces in different eco-geographic regions of Türkiye between 2011- 2021. Samples were tested for the coexistence of honeybee pathogens with IAPV. The sampled apiaries were evaluated for other bee pathogens such as Acute bee paralysis virus, Black queen bee virus, Chronic bee paralysis virus, Deformed wing virus, Kashmir bee virus, Lake Sinai virus, Sacbrood virus, Varroa mites, and Nosema sp. analyzed. Pathogen-specific RT-PCR assay was used for bee viruses. IAPV positivity was found to be 52.5% in apiaries. 97.5% of the sampled apiaries were positive for at least one pathogen. According to the results of this study, the presence of IAPV in apiaries suffering from colony loss and CCD-like problems was higher than in previous reports, and viruses of different species, Nosema sp., and varroa infestation were found to be frequently encountered. The results suggest that the coexistence of IAPV and multiple pathogens may be effective in colony losses.

The Multiple Perspective Response of Vegetation to Drought on the Qinghai-Tibetan Plateau

The Qinghai-Tibetan Plateau (QTP) is a global center of cold and dry, where the most extensive fragile alpine vegetation exists. Quantitative analysis of drought event characteristics and vegetation response to drought on the QTP is indispensable for understanding the increasing drought events in a warming climate which exacerbate adverse influence on extremely alpine ecosystems. Here, using the standardized precipitation evapotranspiration index (SPEI) and the normalized difference vegetation index (NDVI) from 2000 to 2018, this study analyzed the characteristics of drought events, their temporal impacts, and the stability of vegetation response to drought on the QTP. Results showed that: the characteristics of drought events on the QTP have clear spatial heterogeneity. When compared to the east monsoon region, most of the western regions have higher frequency and lower intensity of drought events. Drought has significant temporal effects on vegetation in grassland areas of the QTP during the growing season, which reach their peak in July and August. The 0–1-month and 3-month time scales were the optimal lagged and accumulated time during the growing season, respectively. The stability of vegetation response to drought showed significant spatial heterogeneity and varied with eco-geographical regions and vegetation types. Generally, forest areas showed high resistance (74.09) and resilience (2.26), followed by crop and grassland areas.

Molecular phylogenetics shed light on polyploid speciation in gorses (Ulex, Fabaceae: Genisteae) and on the origin of the invasive Ulex europaeus

Abstract Hybridization and polyploidy are key evolutionary forces in plant diversification, and their co-occurrence in the context of allopolyploid speciation is often associated with increased ability to colonize new environments and invasiveness. In the genus Ulex (Fabaceae), the European gorse (Ulex europaeus subsp. europaeus) is the only invasive and the only polyploid that has recently spread in different eco-geographical regions across the world. Understanding what confers such ecological advantages to this species, compared to its diploid and polyploid congeners, first requires clarification of the ecogeographical and evolutionary context of its formation. To achieve this, the geographical distributions of all Ulex spp. were estimated from species occurrence records, and phylogenetic analyses including all Ulex spp. were performed based on four nuclear (ITS and ETS nrDNA) and plastid (rps12 intron and trnK-matK) regions. The resulting trees were dated using a secondary calibration. Patterns of DNA sequence variation and dated phylogenetic trees were then interpreted in light of previous knowledge of chromosome numbers in Ulex to infer past events of polyploid speciation in the genus. We show that: (1) most current Ulex spp. radiated in the Iberian Peninsula during the past 1–2 Myr; (2) the history of Ulex was punctuated by multiple whole-genome duplication events; and (3) U. europaeus subsp. europaeus is the only gorse taxon that was formed by hybridization of two well-differentiated lineages (which separated c. 5 Mya) with wide climatic ranges (currently represented by Ulex minor and Ulex europaeus subsp. latebracteatus), possibly contributing to the invasive nature and wider climatic range of U. europaeus subsp. europaeus. These findings provide a much-needed evolutionary framework in which to explore the adaptive consequences of genome mergers and duplication in Ulex.

A comprehensive meta-analysis of the impacts of intensified drought and elevated CO2 on forage growth

Forage crops are used worldwide as key feed sources for dairy systems. However, their productivity and quality are limited due to intensified drought events, elevated carbon dioxide (CO2), and their interaction with climate change, with consequences for the security of animal husbandry and the agricultural economy. Although studies have quantified the impacts of such stresses on forage growth, these impacts have been less systematically investigated in a global context due to differences among various forage groups, regional microclimates, and environmental factors. Herein we employed nine forage growth-related variables involving three perspectives, i.e., photosynthetic parameters, production, and quality, from research articles published between 1990 and 2021 via a meta-analysis. A linear mixed-effect model was then used to explore the quantitative relationship between these factors in a restricted dataset. Decreasing trends in all four photosynthetic parameters were detected across different eco-geographical regions with increasing drought stress. The maximum decrease in DMY occurred in the Mediterranean, with 52.8% under drought conditions. Globally, eCO2 significantly increased photosynthetic rate (Pn) and instantaneous water use efficiency (WUEi) by 40.8% and 62.1%, respectively, which also had positive effects on forage dry matter yield (DMY) (+25.1%), especially for forage in Northern Europe. However, this stress would significantly decrease forage quality by decreasing crude protein (CP) (−19.7%) and nitrogen content (N content) (−13.5%). These negative impacts would be aggravated under the co-occurrence of drought and eCO2, including a significant increase in WUEi (+111.1%) and a decrease in DMY (−12.3%). Gramineae showed a more sensitive response to drought stress in photosynthetic parameters and DMY than Leguminosae, but the latter exhibited a better response in photosynthetic parameters and production under eCO2. Our analysis provides a consensus concerning how the growth parameters of forage have changed under environmental stresses.

Characterization of water use efficiency changes in Tibetan Plateau grasslands based on eco-geographic zoning.

Water use efficiency (WUE) is an effective indicator to study the coupling of terrestrial carbon and water cycles. The Tibetan Plateau (TP) is the most important ecological security barrier in China, and it is important to understand the characteristics of WUE and the change mechanism to study the carbon and water cycles of plateau ecosystems and the rational use of water resources. This study analyzes the spatial and temporal characteristics of WUE on the TP and the influence of climate factors on WUE based on the gross primary productivity (GPP) and evapotranspiration (ET) data from GLASS. The results show that from 1985 to 2018, the WUE of the TP is on the rise under the combined effect of GPP and ET; the regions with higher mean WUE values are the southeastern and eastern parts of the plateau, and the low value areas are the central and northwestern parts of the plateau. Compared with precipitation, WUE is influenced by temperature over a larger area. The correlations between precipitation and temperature and WUE in different eco-geographic regions are complex, and there is a threshold effect on the correlation between WUE and temperature and precipitation. Temperature is the main driver of WUE changes in HIIA and HIB1 regions, while precipitation has a greater impact on WUE changes in HIIC2, HIIC2, HIC2, HIID3, and HIIC regions. Precipitation, temperature, and elevation are the main factors explaining the variation of WUE in the TP. According to the risk detector, it can be determined that grassland vegetation in warm and humid steep areas of low and medium elevations is more able to maintain efficient use of water. Meanwhile, grasslands located in the shade of northern slopes have weaker transpiration, which is conducive to vegetation accumulation of growth water, and thus can ensure higher WUE. The related study can provide a reference for the response of vegetation WUE to global changes in key climatic regions.

Morphometric and meristic diversity of the species Androctonus crassicauda (Olivier, 1807) (Scorpiones: Buthidae) in Saudi Arabia.

Intraspecific molecular and morphological variations among geographically isolated populations are useful for understanding the evolutionary processes, which is considered early stage of allopatric speciation. Also, the knowledge of the regional variation of scorpion venom composition is needed to improve antivenom therapeutic management. Androctonus crassicauda (Olivier, 1807) is the most common and medically important species in Arabia and the Middle East. Therefore, this study aimed to investigate the geographic morphological variation among A.crassicaudapopulations, regarding its geographical distribution in unexplored arid regions in Saudi Arabia. Samples were collected and examined morphologically under a dissecting microscope from different four eco-geographical regions. The results of ANOVA and multivariate statistical analyses provide strong evidence of geographical variation. The two populations from OTU3 and OUT4 showed the greatest degree of morphological difference from populations of OUT1 and OUT2. Each OTU3 and OTU4 populations showed significant speciation without overlapping in the two groups, while the remaining overlapped groups comprised two other populations. Several body variables influenced male separation, including carapace posterior width, metasoma 3rd length, and metasoma 2nd length. For females, telson length, metasoma 1st width, and sternite 7th width were highly influential variables. Such variation may suggest the existence of cryptic taxa within A. crassicauda populations in Saudi Arabia. Moreover, metasoma ratios can be used as good indicators in intraspecific variation studies of Scorpions.

Assessment of Diversity among Important Brinjal (Solanum melongena) Cultivars Using Morphological Markers

Background. Solanum melongena is a medicinally important vegetable crop that belongs to the family Solanaceae, which is cultivated worldwide. Methodology. In the present study, 22 eggplant varieties from the different ecogeographical regions were evaluated for nine quantitative and twenty-two qualitative morphological characters. A significant divergence was observed in all characters and wide regional variations for plant characteristics, flower, and fruit characteristics. Principle component analysis (PCA) was performed using PAST3 software to determine the relationship among eggplant accessions. Results. The principal component analysis showed that the first two principal component axes explained 97.17% of the total multivariate variation. Cluster analysis using the Unweighted Pair Group Method of Arithmetic Means (UPGMA) grouped the 22 eggplant accessions into two main clusters based on similarities in morphological characteristics. The study showed that the Solanum melongena accessions belonging to Pakistan and other geographical regions of the world possess marked variation in fruit weight, fruit shape, fruit color, leaf spine, number of locules in fruit, plant height, and flower color. Conclusion. Based on morphological diversity, the best cultivars of eggplant that show better yield can be selected for farmers.