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Paphiopedilum is among the most popular ornamental orchid genera due to its unique slipper flowers and attractive leaf coloration. Most of the Paphiopedilum species are in critical danger due to over-exploitation. They were listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which prevents their being traded across borders. While most Paphiopedilum species are distinctive, owing to their respective flowers, their vegetative features are more similar and undistinguished. Hence, the conservation of these species is challenging, as most traded specimins are immature and non-flowered. An urgent need exists for effective identification methods to prevent further illegal trading of Paphiopedilum species. DNA barcoding is a rapid and sensitive method for species identification, at any developmental stage, using short DNA sequences. In this study, eight loci, i.e., ITS, LEAFY, ACO, matK, trnL, rpoB, rpoC1, and trnH-psbA, were screened for potential barcode sequences on the Vietnamese Paphiopedilum species. In total, 17 out of 22 Paphiopedilum species were well identified. The studied DNA sequences were deposited to GenBank, in which Paphiopedilum dalatense accessions were introduced for the first time. ACO, LEAFY, and trnH-psbA were limited in amplification rate for Paphiopedilum. ITS was the best single barcode. Single ITS could be used along with nucleotide polymorphism characteristics for species discrimination. The combination of ITS + matK was the most efficient identification barcode for Vietnamese Paphiopedilum species. This barcode also succeeded in recognizing misidentified or wrongly-named traded samples. Different bioinformatics programs and algorithms for establishing phylogenetic trees were also compared in the study to propose quick, simple, and effective tools for practical use. It was proved that both the Bayesian Inference method in the MRBAYES program and the neighbor-joining method in the MEGA software met the criteria. Our study provides a barcoding database of Vietnamese Paphiopedilum which may significantly contribute to the control and conservation of these valuable species.

Orchidaceae is one of the most valuable plant groups all over the world, and is also an impressively large and complex family of flowering plants. Effective molecular tools used for the identification of orchid species should be developed to support traditional morphological approaches. This study reviews most of the DNA fragments that have been used as taxon identifiers in researches conducted on Orchidaceae in order to assess potential molecular markers and metric measurements for the identification of orchid species.

Salinity is one of the major abiotic stresses, and it limits rice production in many worldwide areas. A lot of attention has been paid to developing rice salinity tolerance to cope with climate change. This study is based on the genome sequence databases of 36 Vietnamese landraces. The candidate gene, SRWD2, has been predicted and identified. The salt responsive WD40 protein 2 is involved in salt tolerance yield of nine rice landraces. Specifically, nine homologous segments of the sequences were found to be components of the CSD nucleotides, which is shown to be similar to the reference genome LOC_Os02g48964.1 and LOC_Os02g48964.1 CDS, respectively. At the same time, the functional marker, SRWD2add14, was designed to identify the candidate gene, SRWD2, based on its size as 150 bp (candidate gene tolerant to salinity) and 136 bp (different sequences to compare SRWD2-reference genome sequence). The findings show that Mot bui do landrace carries the candidate gene, SRWD2 (homozygote). The rice genotype should be used as a potential material for rice breeding to develop salt tolerance in rice varieties.

Elucidation of the rice genomewill not only broaden our understanding of genetic characterization of the agronomic characteristics but also facilitate the rice genetic improvement through marker assisted breeding. However, the genome resources of aromatic rice varieties are largely unexploited. Therefore, the whole genome of two elite aromatic traditional japonica rice landraces in North Vietnam, TamXoan BacNinh (TXBN), and TamXoanHaiHau(TXHH), was sequenced to identify theirgenome-wide polymorphisms. Overall, we identified over 40,000 novel polymorphisms in each aromatic rice landrace. Although a discontinuous 8-bp deletion and an A/T SNP just upstream the 5-bp deletion in exon 7 of BADH2 gene were present in both rice landraces, the number of SNP high resolution regions of TXBN was six times higher than that of TXHH. Furthermore, several hot spot regions of novel SNPs and indels were found in both genomes, providing their potential gene pools related to aroma formation. The genomic information of two aromatic rice landraces described in this study will facilitate the identification of fragrance-related genes and the genetic improvement of rice. [ABSTRACT FROM AUTHOR]