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Genetic variation and population structure may reflect important information for invasion success of exotic plant species and thus help improve management of invasive plants. Spartina alterniflora is an invasive plant that is a major threat to the economy and environment of the coastal regions in China. We analyzed the genetic structure and diversity of six populations of S. alterniflora differing in invasion histories in Guangxi, China. A total of 176 individuals from the six populations produced 348 AFLP fragments. The average heterozygosity was significantly lower than in the native population. And genetic bottlenecks were also detected in most populations. Standardized FST statistics (Φpt = 0.015) and AMOVA results indicated weak genetic differentiation. Genetic admixture and obviously isolation by distance indicated populations in Guangxi come from a pre-admixed population by a single introduction. High phenotypic variations of S. alterniflora in Guangxi influenced by soil salinity and temperature might be an important reason for the successful invasion. [ABSTRACT FROM AUTHOR]

Two novel strains GSK1Z-4-2T and MQZ15Z-1 were isolated from branches of mangrove plants collected from Guangxi Zhuang Autonomous Region, China. Both strains were Gram-negative, aerobic, non-flagellated and non-spore-forming bacteria. The comparison of 16S rRNA gene sequences initially indicated that the two strains were assigned to the genus Ancylobacter with sharing the highest similarity to Ancylobacter pratisalsi DSM 102029T (97.3%). The 16S rRNA gene sequence similarity, average nucleotide identity (ANI) and in silico DNA-DNA hybridization (is DDH) values between strains GSK1Z-4-2T and MQZ15Z-1 were 99.9%, 97.4% and 77.4%, respectively, which revealed that the two strains belonged to the same species. Phylogenetic analyses based on 16S rRNA gene sequences and the core proteome showed that the two strains formed a well-supported cluster with A. pratisalsi DSM 102029T. Moreover, the ANI and is DDH values between strain GSK1Z-4-2T and A. pratisalsi DSM 102029T were 83.0% and 25.8%, respectively, demonstrating that strain GSK1Z-4-2T was a previously undescribed species. Meanwhile, strains GSK1Z-4-2T and MQZ15Z-1 exhibited most of chemotaxonomic and phenotypic features consistent with the description of the genus Ancylobacter. Based on the polyphasic data, strains GSK1Z-4-2T and MQZ15Z-1 should represent a novel species of the genus Ancylobacter , for which the name Ancylobacter mangrovi sp. nov. is proposed. The type strain is GSK1Z-4-2T (=MCCC 1K07181T = JCM 34924T). [ABSTRACT FROM AUTHOR]

Two novel strains KQZ13P-1T and MAQZ13P-2 were isolated from bark of Sonneratia apetala collected from Maowei sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, China. Two strains were Gram-positive, aerobic, non-spore-forming, no diffusion pigment actinobacterial strains and investigated by a polyphasic approach to determine their taxonomic position. The average nucleotide identity (ANI) value and the digital DNA-DNA hybridization (dDDH) value between the two strains were 99.9% and 99.7%, respectively, suggesting that they belonged to the same species. The ANI and dDDH values between strain KQZ13P-1T and five Phycicoccus species were 74.4–95.3% and 20.1–61.5%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that the two strains were member of the genus Phycicoccus and were closely related to P. jejuensis NRRL B-24460T (99.2% sequence similarity), followed by P. ginsengisoli DCY87T (97.5–97.6%). Moreover, based on 88 core genes, the phylogenomic tree indicated that the two strains clustered with P. jejuensis NRRL B-24460T. The cell-wall peptidoglycan of both strains contained meso -diaminopimelic acid. The major fatty acids in two strains were C 17:1 ω 8 c , iso-C 15:0 and iso-C 16:0. The major polar lipids included diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE) and phosphatidylinositol (PI). Based on phylogenetic, phenotypic and chemotaxonomic analysis, strains KQZ13P-1T and MAQZ13P-2 represent a novel species of the genus Phycicoccus , for which the name Phycicoccus mangrovi sp. nov. is proposed. The type strain is KQZ13P-1T (=CGMCC 1.18973T = JCM 34556T). [ABSTRACT FROM AUTHOR]