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Leucobryum aduncum is a moss species reported in many Southeast Asian regions, often found in forests with a high humidity. Climate change may impact the future distribution of this species. This study aimed to model the current distribution and predict the impact of climate change on L. aduncum distribution in the next 50 years across Southeast Asia. In the process, relevant climate variables in the distribution of the species were also identified. The occurrence data of this species with current and future climate models from CMIP6 under moderate (SSP2) scenarios were used to predict current and future L. aduncum distributions. Under the current climate, the predicted suitable areas for L. aduncum included most mountainous areas. However, many Southeast Asian areas showed a lower probability of finding this species in the next 50 years. The distribution area of this species will dramatically decrease by 50.16% in the current area. The most important ecological variables included the “mean temperature of the driest quarter” and the “annual temperature range”. This study suggests the possible impacts of an increased temperature and the scale of climate change on the distribution of sensitive plants like bryophytes.

During the filmy fern (Hymenophyllaceae) diversity study in Thailand, the genus Didymoglossum was investigated using morphological data and molecular phylogenetic analyses of the chloroplast rbcL region. This study revealed a new species, Didymoglossum radiatum S.Chokrassameehirun, Kraichak & Jaruwatt., sp. nov. , which is currently known only from peninsular Thailand. This taxon resembles D. tahitense in possessing peltate fronds but differs in frond size, the structure of false veinlets, and the appearance of its sori. The phylogenetic results further confirmed the distinct phylogenetic positions of D. henzaianum and D. mindorense , which were also newly recorded and described for Thailand.

Sonneratia caseolaris is a pioneer species in mangrove. It can naturally grow in both saltwater and freshwater. The study was aimed at investigating and comparing the anatomical character of the S. caseolaris plants growing in different conditions and how they coped with salinity. The anatomical characteristics of roots, stems, petioles and leaf blade were investigated. The plant samples were prepared into permanent slides using a paraffin method, while the wood samples were made into permanent slides using a sliding microtome technique. Tissue clearing of leaf blade and scanning electron microscopic analysis of wood were performed. In addition, sodium chloride content in various organs and tissues was examined. It was found that cable root, stem and leaf blade showed some different anatomical characteristics between the two conditions. Periderm is a prominent tissue in saltwater roots. Tanniferous cells were observed in pneumatophores, petioles, stems and leaf blades of saltwater plants, but not found in pneumatophores and lamina of freshwater plants. Mesophyll thickness was lower in the saltwater condition. The vessel density was significantly higher in the saltwater condition than in the freshwater condition, whereas the vessel diameters in the freshwater condition were significantly higher than those in the saltwater condition. From the results, it can be concluded that root periderm plays an important role in salt exclusion, and the occurrence of tanniferous cells is associated with salt elimination.

Background The genus Aneura Dumort. is a simple thalloid liverwort with cosmopolitan distributions. Species circumscription is problematic in this genus due to a limited number of morphological traits. Two species are currently reported from Thailand, including A. maxima and A. pinguis. At the global scale, A. pinguis is considered a cryptic species, as the species contains several distinct genetic groups without clear morphological differentiation. At the same time, the identity of A. maxima remains unclear. In this work, we examined the level of diversity of Aneura species found in Thailand using both morphological and molecular data. Methods We measured the morphological traits and generated the molecular data (four markers: trnL-F, trnH-psbA, rbcL, and ITS2) from the Thai specimens. The concatenated dataset was then used to reconstruct phylogeny. Species delimitation with GMYC, bPTP, ASAP, and ABGD methods was performed to estimate the number of putative species within the genus. Results The samples of A. pinguis formed several clades, while A. maxima sequences from Poland were grouped in their clade and nested within another A. pinguis clade. We could not recover a sample of A. maxima from Thailand, even from the reported locality. Two putative species were detected among Thai Aneura samples. However, no morphological trait could distinguish the specimens from the two observed genetic groups. Discussion The previously observed paraphyletic nature of A. pinguis globally was also found among Thai samples, including several putative species. However, we could not confirm the identity of A. maxima from Thai specimens. The previous report could result from misidentification and problematic species circumscription within Aneura. The results highlighted the need to include multiple lines of evidence for the future taxonomic investigation of the group.

Duckweeds have emerged as frontier plants in research, food, and bioenergy applications. Consistency in genetic and morphological traits within species is therefore crucial for their effective use. Thailand hosts diverse duckweed populations with representatives from four of the five genera and at least four species recorded. However, the extent of genetic and morphological variation within these species in Thailand remains unclear. Here, we investigated the genetic and morphological variation in four duckweed species—Landoltia punctata, Lemna aequinoctialis, Spirodela polyrhiza, and Wolffia globosa—collected from 26 sites across Thailand. Using the multilocus sequence typing approach based on three chloroplast genes (rbcL, atpF–atpH, and psbK–psbI), we show that genetic variation in duckweed is distinct at both inter-species and intra-species levels. Among these four species, Lemna aequinoctialis exhibits the highest genetic variation, forming four distinct phylogenetic clusters. This is followed by Spirodela polyrhiza, Wolffia globosa, and Landoltia punctata. In addition, we observe that morphological variation, particularly frond aspect ratio, varies significantly among clusters but remains consistent within each cluster of each species. These findings suggest that duckweed populations in Thailand exhibit substantial genetic variation at the intraspecific level, which is closely associated with frond morphological variation.

The North African catfish ( Clarias gariepinus ) is a significant species in aquaculture, which is crucial for ensuring food and nutrition security. Their high adaptability to diverse environments has led to an increase in the number of farms that are available for their production. However, long-term closed breeding adversely affects their reproductive performance, leading to a decrease in production efficiency. This is possibly caused by inbreeding depression. To investigate the root cause of this issue, the genetic diversity of captive North African catfish populations was assessed in this study. Microsatellite genotyping and mitochondrial DNA D-loop sequencing were applied to 136 catfish specimens, collected from three populations captured for breeding in Thailand. Interestingly, extremely low inbreeding coefficients were obtained within each population, and distinct genetic diversity was observed among the three populations, indicating that their genetic origins are markedly different. This suggests that outbreeding depression by genetic admixture among currently captured populations of different origins may account for the low productivity of the North African catfish in Thailand. Genetic improvement of the North African catfish populations is required by introducing new populations whose origins are clearly known. This strategy should be systematically integrated into breeding programs to establish an ideal founder stock for selective breeding.

Duckweed has attracted considerable attention for its high protein content, rapid growth, and broad potential in biotechnological applications. Understanding key phenotypic traits is crucial for unlocking and maximizing this potential. While most studies on duckweed growth have been conducted under natural or non-sterile conditions, here we minimize environmental influences and focus on the genetic component of growth by assessing growth performance under axenic culture. In this study, we measured relative growth rate (RGR) in four duckweed species, Landoltia punctata (G. Mey.) Les & D. J. Crawford, Lemna aequinoctialis Welw., Spirodela polyrhiza (L.) Schleid., and Wolffia globosa (Roxb.) Hartog & Plas. collected from various natural locations across Thailand. A total of six to seven strains were tested for each species. The relative growth rates of studied species ranged from 0.012 day−1 in S. polyrhiza to 0.162 day−1 in W. globosa. Significant intraspecific variation was observed in L. punctata, S. polyrhiza, and W. globosa, with the coefficients of variation between 9.6 to 109.9 percent. Each strain showed distinct growth characteristics: Most displayed a steady growth pattern, whereas W. globosa showed exponential growth at Day 35 after the start of experiment. The results provide the first systematic comparisons of baseline growth rate data for duckweed species in Thailand. These findings advance the understanding of strain-specific growth traits in duckweed and establish a standardized protocol for evaluating growth traits under axenic conditions, providing a basis for future research and applications.

The fragmentation of habitats and hunting have impacted the Asian woolly-necked stork (Ciconia episcopus), leading to a serious risk of extinction in Thailand. Programs of active captive breeding, together with careful genetic monitoring, can play an important role in facilitating the creation of source populations with genetic variability to aid the recovery of endangered species. Here, the genetic diversity and population structure of 86 Asian woolly-necked storks from three captive breeding programs [Khao Kheow Open Zoo (KKOZ) comprising 68 individuals, Nakhon Ratchasima Zoo (NRZ) comprising 16 individuals, and Dusit Zoo (DSZ) comprising 2 individuals] were analyzed using 13 microsatellite loci, to aid effective conservation management. Inbreeding and an extremely low effective population size (Ne) were found in the KKOZ population, suggesting that deleterious genetic issues had resulted from multiple generations held in captivity. By contrast, a recent demographic bottleneck was observed in the population at NRZ, where the ratio of Ne to abundance (N) was greater than 1. Clustering analysis also showed that one subdivision of the KKOZ population shared allelic variability with the NRZ population. This suggests that genetic drift, with a possible recent and mixed origin, occurred in the initial NRZ population, indicating historical transfer between captivities. These captive stork populations require improved genetic variability and a greater population size, which could be achieved by choosing low-related individuals for future transfers to increase the adaptive potential of reintroduced populations. Forward-in-time simulations such as those described herein constitute the first step in establishing an appropriate source population using a scientifically managed perspective for an in situ and ex situ conservation program in Thailand.

Despite cassava’s significance as a staple crop in tropical and subtropical regions, there is limited understanding of how specific environmental factors influence the productivity of different cassava varieties. This study investigated the complex relationship between environmental factors and cassava yield traits such as fresh root yield (FRY), dry root yield (DRY), starch content (SC) and harvest index (HI) using data obtained from six cassava varieties cultivated for five seasons (2014 to 2019) across nine major locations in Thailand. A total of 41 distinct environmental trials were conducted, representing a range of conditions encompassing various rainfall and temperature patterns, as well as soil characteristics. Field experiments were conducted using a randomized complete block design with four replicates at each location. Climatic data, including air temperature and precipitation, along with soil parameters, were recorded and analyzed to assess their impact on cassava yield traits. Regression analysis revealed distinct coefficients for environmental factors affecting different yield parameters. Cumulative precipitation during 4-5 months after planting (MAP) and 6-10 MAP, as well as the average air temperature during 2-3 MAP and 6-10 MAP, positively influenced cassava yield. However, negative correlations were observed between soil organic matter and HI. Furthermore, the average air temperature at 4-5 MAP, 6-10 MAP, and 1-10 MAP negatively impacts FRY and DRY, while cumulative precipitation during 1 MAP and 2-3 MAP negatively impacts the HI and SC traits. Varieties exhibited varied responses to environmental factors, emphasizing the need to consider specific variety responses for accurate interpretation. The study introduces a novel approach for selecting specific cassava genotypes adapted to distinct environmental conditions by grouping regression coefficients across evaluated parameters. These findings provide insights for optimizing agricultural practices to enhance cassava productivity and contribute to sustainable crop cultivation.

Cassava breeding is a critical aspect of sustainable agriculture to address the challenges of food security and climate change. The present study aimed to assess the combining ability of six Thai cassava elite varieties for four key traits, including fresh root yield (FRY), fresh shoot yield (FSY), harvest index (HI) and starch content (SC) through an analysis of the diallel mating design over two years. Parental lines HB80 and R5 showed significant positive general combining ability (GCA) effects for high SC; R1 and HB80 for low FSY; and R1 for high FRY and HI. The genetic effects for FSY, SC and HI were primarily influenced by the GCA of the progenitors, while specific combining ability (SCA) was more important for the FRY than the other three traits. Cultivation conditions were also found to impact the evaluation of genetic effects, with a poor growing environment affecting the expression of the genotype. This study provides a useful basis for the selection of parental lines for cassava breeding programs and insights into the genetic control of yield and related traits in the Thai elite cassava germplasm.