Neuroprotective Metabolites from Vietnamese Marine Derived Fungi of Aspergillus and Penicillium Genera

Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity.     

Genetic diversity estimates in Cicer using AFLP analysis

Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic variation among cultivated chickpea and wild Cicer relatives. In total, 214 marker loci were assessed, of which 211 were polymorphic (98.6%) across the 95 accessions that represented 17 species of Cicer. The genetic variation within a species was highest in C. pinnatifidum followed by C. reticulatum and lowest in C. macracanthum. Three main species groups were identified by UPGMA clustering using Nei's pair‐wise distance calculations. Group I included the cultivated species C. arietinum, C. reticulatum and C. echinospermum. Within this group, C. reticulatum accessions were clustered closest to the C. arietinum cultivars ‘Lasseter’, ‘Kaniva’ and ‘Bumper’, supporting the hypothesis that C. reticulatum is the most probable progenitor of the cultivated species. Cicer bijugum, C. judaicum and C. pinnatifidum were clustered together creating group II. Group III contained all nine perennial species assessed and two annual species C. yamashitae and C. cuneatum. The genetic distance detected between group I and group III (0.13) was equivalent to the genetic distance detected between group I and group II (the primary and annual tertiary species, respectively; 0.14). This indicated that the perennial tertiary species may be as valuable for increasing variation to incorporate novel germplasm in the cultigen as the annual tertiary species.     

A morphological analysis of the skull size and shape of Kerivoulinae (Chiroptera: Vespertilionidae) from Vietnam

Southeast Asia is a region of high biodiversity, containing species of plants and animals that are yet to be discovered. In this region, bats of the subfamily Kerivoulinae are widespread and diverse with six species recorded in Vietnam. However, the taxonomy of the Kerivoulinae in Asia is complicated. In our study, we used diagnostic characters and multivariate analysis to determine morphological differences between the genera Kerivoula and Phoniscus. We showed that the two genera are distinguishable by the size of second upper incisors, the shape of skull, nasal sinus, canines, second upper and lower premolars. In addition, the two genera can be osteometrically separated by measurements of the braincase height, interorbital width and shape of anterior palatal emargination. Our data clearly revealed the morphological variations in the skull shape of Kerivoula hardwickii in Vietnam. This suggests a possible separation into three morphotypes, representing cryptic species supported by statistical differences with wide variation in skull shape, size and teeth. These results demonstrated Kerivoula hardwickii can be separated three subspecies, and the result will serve as the basis for the future assessment and classification of this group in Southeast Asia.     

Evaluation of fly ash,apatite and rice straw derived-biochar in varying combinations for in situ remediation of soils contaminated with multiple heavy metals

ABSTRACT

In

-situ sorbent amendment is a relatively low-cost, low-impact approach for remediation of soil contaminated with heavy metals (HMs), and thus is considered a way to be favored in developing countries. In this study, materials of non-hazardous, alkaline agronomic and industrial by-products were used as sorbents to explore their capacity of in situ immobilization of multiple HMs in mining-impacted arable soil. These sorbents included fly ash (FA), biochar (BC) and apatite (AP) and they were implemented with varying ratios of combinations. Results of soil microcosm tests showed that after incubation for 90 days, concentrations of Pb, Zn, and Cd in their exchangeable forms determined by a sequential extraction method significantly decreased in amended soils, as opposed to the unamended control. Of the five sets of amendments, the composite of FA, BC, and AP resulted in the maximum reduction (up to 80%) in the mobility of Pb, Zn, and Cd in soils. The mechanisms underlying the immobilization of HMs in amended soils might involve processes of surface precipitation, ion exchange and complexation, in which the physicochemical properties of sorbent materials played an important role. The immobilization efficacy of sorbent amendments on HMs in soil was further supported by pot experiments in which significant inhibition of HM accumulation in the belowground and aboveground tissues of maize was observed after 50-day cultivation in amended soils as compared with control soil. Together, these results suggest that the application of cost-saving and environmentally friendly materials derived from wastes as sorbents to remediate soils contaminated with multiple HMs is promising for developing countries like Vietnam.     

Detection and molecular characterization of sugarcane grassy shoot phytoplasma in Vietnam

Sugarcane is an important cash crop in Vietnam and has been widely promoted at national and provincial level. In 2006, a new disease was discovered in sugarcane in the Nghean Tate&Lyle Sugar Mill in Nghean Province in north-central Vietnam. The key symptoms were the formation of green grassy shoots around the base of mature stools. We applied nested polymerase chain reaction (PCR) using P1/P7 and R16F2n/R16R2 for detection and characterization of phytoplasma from the symptomatic tissues. PCR products of the expected size (approx. 1200?bp) were obtained from the 16S rDNA of the phytoplasma. The restriction fragment length polymorphism profiles indicated that all samples were infected by the same phytoplasma. Phylogenetic analysis confirmed that the SCGS phytoplasma from Vietnam belong to the 16SrXI group, formerly Rice Yellow Dwarf group.     

Growth and wood basic density of acacia hybrid clones at three locations in Vietnam

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P < 0.001) differences in height and diameter at breast height (DBH) among 22 tested clones at 4 years. At Long Thanh, twelve hybrid clones did not differ significantly in DBH at age 3 years, but did (P < 0.001) at age 5 years. At the two northern sites the acacia hybrid clones had significantly greater DBH than control seedlots of the parental species. At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m⁻³ at Yen Thanh at age 8 years, and 473 kg m⁻³ at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m⁻³. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.