tropical asia
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2022 ◽  
Author(s):  
Wen-Juan Wang ◽  
Jing Wen ◽  
Pastor L. Malabrigo ◽  
Ming-Xun Ren

Abstract Background Agroforestry system is one of promising directions for developing sustainable agriculture because the intercropping of crops and trees may facilitate resource cycling and avoid soil degradation. Bombax ceiba (Malvaceae), a tall tree with red flowers blooming in Spring, is traditionally planted in rice paddies in tropical Asia, while the roles of B. ceiba in the agroecosystem remain unexplored.Methods In this paper, we investigated and assessed spatiotemporal variations of soil nutrient contents and soil bacterial and fungal communities along the distance gradients to B. ceiba during three reproductive stages of rice, i.e. booting, heading, mature, in a typical Bombax-dominated rice paddy on Hainan Island, South China.Results B. ceiba in rice paddy could improve the soil nutrient conditions, particularly available K and soil organic carbons. The relative abundance of Chloroflexi and Ascomycota increased while Actinobacteria decreased along the distance gradient to B. ceiba. In addition, the relative abundance of Firmicutes was highest at harvesting stage of rice, while Acidobacteria was richer in the early reproductive stage of rice. Soil potassium content was the principal driver in shaping soil bacterial diversity and composition, while fungal community was mainly affected by soil nitrogen.Conclusions Our results provide evidences for positive influences of B. ceiba on biotic and abiotic traits of rice paddy soils and thus lend supports to the ecological basis of this tropical Asian endemic traditional Agroforestry system, which could increase resource cycling and paddy stability and have the potential to reduce carbon emission.


2022 ◽  
pp. 1-32
Author(s):  
Robert J. Morley ◽  
Harsanti P. Morley
Keyword(s):  

MycoKeys ◽  
2021 ◽  
Vol 85 ◽  
pp. 87-108
Author(s):  
Lun-Sha Deng ◽  
Rui Kang ◽  
Nian-Kai Zeng ◽  
Wen-Jie Yu ◽  
Cheng Chang ◽  
...  

An accurate identification of poisonous mushrooms and the confirmation of the toxins involved are both of great importance in the treatment of mushroom poisoning incidents. In recent years, cases of mushroom poisoning by Inosperma spp. have been repeatedly reported from tropical Asia. It is urgent to know the real species diversity of Inosperma in this region. In the present study, we proposed two new Inosperma species from tropical Asia, namely I. muscarium and I. hainanense. They were described based on morphology and multilocus phylogeny. Detailed descriptions, color photographs and the discussion with other closely related species of the two new taxa were provided. In addition, a comprehensive muscarine determination of these two new species using ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach has been performed. Results showed that these two species were muscarine positive, with a content of 16.03 ± 1.23 g/kg in I. muscarium and a content of 11.87 ± 3.02 g/kg in I. hainanense, much higher than the known species I. virosum. Recovery of muscarine ranged from 93.45% to 97.25%, and the average recovery is 95.56%.


F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 398
Author(s):  
Mohamad Faiz Hamzah ◽  
Azimah Amanah ◽  
Wai Kwan Lau

Averrhoa bilimbi is a fast-growing tree widely found in countries of tropical Asia. Due to easy accessibility and traditional knowledge, various parts of this plant are adopted as folk medicine and a natural health remedy. Recently, beneficial effects of bilimbi in combating obesity including its potential antihyperlipidemic and hypoglycemic activities have been discovered. This paper reports the successive isolation and purification of bioactive compounds from the leaf of bilimbi that corresponds to brown adipocyte activation. Bilimbi ethanolic extract underwent bioassay-guided partitioning and fractionation. The n-hexane partition exhibited highest brown adipogenesis potential via adipomyocytes differentiation. Further isolation of this active partition yielded 10 fractions. Active fractions with the highest brown adipogenesis potential were further evaluated via the adipomyocytes assay. Chemical structures of the constituents were elucidated by gas chromatography-mass spectrometry (GC-MS). Major phytocomponents in the n-hexane partition include hexadecanoic acid, phytol, 9-Octadecenoic acid (Z)- and squalene.


2021 ◽  
Author(s):  
Sreepat Jain ◽  
Krzysztof Banaś ◽  
Mariusz Salamon ◽  
Bartosz J. Płachno

Abstract The establishment of a database of naturalized species is the first step in understanding the development and spread of invasion, and serves as a stepping-stone for further detailed studies on the biology and impact of individual species on the ecosystem. Preliminary dataset for such a database of Bangladesh is provided here. The inventory of invasive alien flora comprises of 54 species from 48 genera and 24 families. 54% species originate from South America, 17% from Tropical Asia, Tropical Africa and North America - 5% each, Australia and the Mediterranean region - 2% each and China - 1%. With regard to life form representation, herbs constitute the largest share (63%), followed by trees (13%), shrubs (9%), climbers (8%) and grass (7%). Combating plant Invasive Alien Species (IAS) in Bangladesh is very difficult due to the absence of (1) a cataloged list of identified plant IAS, (2) properly carried out case studies on economic and ecological impacts, (3) unstructured programs on management efforts, (4) awareness campaigns and (5) and coordination between different nodal ministries and agencies. As combating IAS requires an integrated approach, all relevant departments must integrate their approaches, establish a national focal point, education and strictly monitor and implement legal instruments.


Author(s):  
David R. Hall ◽  
Steven J. Harte ◽  
Dudley I. Farman ◽  
Mark Ero ◽  
Alfred Pokana

AbstractThe coconut rhinoceros beetle, Oryctes rhinoceros (Linnaeus 1758) (Coleoptera: Scarabaeidae: Dynastinae) (CRB), is endemic to tropical Asia where it damages both coconut and oil palm. A new invasion by CRB occurred on Guam in 2007 and eradication attempts failed using commonly applied Oryctes rhinoceros nudivirus (OrNV) isolates. This and subsequent invasive outbreaks were found to have been caused by a previously unrecognized haplotype, CRB-G, which appeared to be tolerant to OrNV. The male-produced aggregation pheromone of the endemic, susceptible strain of O. rhinoceros (CRB-S) was previously identified as ethyl 4-methyloctanoate. Following reports from growers that commercial lures containing this compound were not attractive to CRB-G, the aim of this work was to identify the pheromone of CRB-G. Initial collections of volatiles from virgin male and female CRB-G adults from the Solomon Islands failed to show any male- or female-specific compounds as candidate pheromone components. Only after five months were significant quantities of ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by males but not by females. No other male-specific compounds could be detected, in particular methyl 4-methyloctanoate, 4-methyl-1-octanol, or 4-methyl-1-octyl acetate, compounds identified in volatiles from some other species of Oryctes. Ethyl 4-methyloctanoate elicited a strong electroantennogram response from both male and female CRB-G, but these other compounds, including 4-methyloctanoic acid, did not. The enantiomers of ethyl 4-methyloctanoate and 4-methyloctanoic acid were conveniently prepared by enzymatic resolution of the commercially-available acid, and the enantiomers of the acid, but not the ester, could be separated by gas chromatography on an enantioselective cyclodextrin phase. Using this approach, both ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by male CRB-G were shown to be exclusively the (R)-enantiomers whereas previous reports had suggested male O. rhinoceros produced the (S)-enantiomers. However, re-examination of the ester and acid produced by male CRB-S from Papua New Guinea showed that these were also the (R)-enantiomers. In field trapping experiments carried out in the Solomon Islands, both racemic and ethyl (R)-4-methyloctanoate were highly attractive to both male and female CRB-G beetles. The (S)-enantiomer and the corresponding acids were only weakly attractive. The addition of racemic 4-methyloctanoic acid to ethyl 4-methyloctanoate did significantly increase attractiveness, but the addition of (R)- or (S)-4-methyloctanoic acid to the corresponding ethyl esters did not. Possible reasons for the difference in assignment of configuration of the components of the CRB pheromone are discussed along with the practical implications of these results.


Author(s):  
Junta Yanai ◽  
Sota Tanaka ◽  
Atsushi Nakao ◽  
Susumu S. Abe ◽  
Mina Hirose ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Ming Hu ◽  
Chuhao Li ◽  
Xiaofan Zhou ◽  
Yang Xue ◽  
Si Wang ◽  
...  

Ipomoea aquatica is a leafy vegetable widely cultivated in tropical Asia, Africa, and Oceania. Bacterial leaf canker disease has been attacking the planting fields and seriously affecting the quality of I. aquatica in epidemic areas in China. This study examined the microbial composition of I. aquatica leaves with classical symptoms of spot disease. The results showed that Xanthomonas was overwhelmingly dominant in all four diseased leaf samples but rarely present in rhizospheric soil or irrigation water samples. In addition, Pantoea was also detected in two of the diseased leaf samples. Pathogen isolation, identification, and inoculation revealed that both Xanthomonas sp. TC2-1 and P. ananatis were pathogenic to the leaves of I. aquatic, causing crater-shaped ulcerative spots and yellowing with big brown rot lesions on leaves, respectively. We further sequenced the whole genome of strain TC2-1 and showed that it is a member of X. perforans. Overall, this study identified X. perforans as the causal pathogen of I. aquatica bacterial leaf canker, and P. ananatis as a companion pathogen causing yellowing and brown rot on leaves. The correct identification of the pathogens will provide important basis for future efforts to formulate targeted application strategy for bacterial disease control.


Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 515
Author(s):  
Eva Turk ◽  
Jason E. Bond ◽  
Ren-Chung Cheng ◽  
Klemen Čandek ◽  
Chris A. Hamilton ◽  
...  

Reconstructing biogeographic history is challenging when dispersal biology of studied species is poorly understood, and they have undergone a complex geological past. Here, we reconstruct the origin and subsequent dispersal of coin spiders (Nephilidae: Herennia Thorell), a clade of 14 species inhabiting tropical Asia and Australasia. Specifically, we test whether the all-Asian range of Herennia multipuncta is natural vs. anthropogenic. We combine Anchored Hybrid Enrichment phylogenomic and classical marker phylogenetic data to infer species and population phylogenies. Our biogeographical analyses follow two alternative dispersal models: ballooning vs. walking. Following these assumptions and considering measured distances between geographical areas through temporal intervals, these models infer ancestral areas based on varying dispersal probabilities through geological time. We recover a wide ancestral range of Herennia including Australia, mainland SE Asia and the Philippines. Both models agree that H. multipuncta internal splits are generally too old to be influenced by humans, thereby implying its natural colonisation of Asia, but suggest quite different colonisation routes of H. multipuncta populations. The results of the ballooning model are more parsimonious as they invoke fewer chance dispersals over large distances. We speculate that coin spiders’ ancestor may have lost the ability to balloon, but that H. multipuncta regained it, thereby colonising and maintaining larger areas.


2021 ◽  
Vol 63 (3-4) ◽  
pp. 285-296
Author(s):  
V. K. Chandini ◽  
T. Pócs ◽  
C. N. Manju

The genus Diplasiolejeunea is added to the liverwort flora of India from the Kerala part of the Western Ghats reporting two species: Diplasiolejeunea cavifolia Steph. and D. cobrensis Gottsche ex Steph. The genus is known from tropical Asia with eight species. Among them Diplasiolejeunea cavifolia is widespread, but still the genus was not yet recorded from India.


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