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The chloroplast is an essential plant organelle responsible for photosynthesis. Gene duplication, relocation, and loss in the chloroplast genome (cpDNA) are useful for exploring the evolution and phylogeny of plant species. In this study, the complete chloroplast genome of Paris verticillata was sequenced using the 454 sequencing system and Sanger sequencing method to trace the evolutionary pattern in the tribe Parideae of the family Melanthiaceae (Liliales). The circular double-stranded cpDNA of P. verticillata (157,379 bp) consists of two inverted repeat regions each of 28,373 bp, a large single copy of 82,726 bp, and a small single copy of 17,907 bp. Gene content and order are generally similar to the previously reported cpDNA sequences within the order Liliales. However, we found that trnI_CAU was triplicated in P. verticillata. In addition, cemA is suspected to be a pseudogene due to the presence of internal stop codons created by poly(A) insertion and single small CA repeats. Such changes were not found in previously examined cpDNAs of the Melanthiaceae or other families of the Liliales, suggesting that such features are unique to the tribe Parideae of Melanthiaceae. The characteristics of P. verticillata cpDNA will provide useful information for uncovering the evolution within Paris and for further research of plastid genome evolution and phylogenetic studies in Liliales.

Allioideae includes economically important bulb crops such as garlic, onion, leeks, and some ornamental plants in Amaryllidaceae. Here, we reported the complete chloroplast genome (cpDNA) sequences of 17 species of Allioideae, five of Amaryllidoideae, and one of Agapanthoideae. These cpDNA sequences represent 80 protein-coding, 30 tRNA, and four rRNA genes, and range from 151,808 to 159,998 bp in length. Loss and pseudogenization of multiple genes (i.e., rps2, infA, and rpl22) appear to have occurred multiple times during the evolution of Alloideae. Additionally, eight mutation hotspots, including rps15-ycf1, rps16-trnQ-UUG, petG-trnW-CCA, psbA upstream, rpl32-trnL-UAG, ycf1, rpl22, matK, and ndhF, were identified in the studied Allium species. Additionally, we present the first phylogenomic analysis among the four tribes of Allioideae based on 74 cpDNA coding regions of 21 species of Allioideae, five species of Amaryllidoideae, one species of Agapanthoideae, and five species representing selected members of Asparagales. Our molecular phylogenomic results strongly support the monophyly of Allioideae, which is sister to Amaryllioideae. Within Allioideae, Tulbaghieae was sister to Gilliesieae-Leucocoryneae whereas Allieae was sister to the clade of Tulbaghieae- Gilliesieae-Leucocoryneae. Molecular dating analyses revealed the crown age of Allioideae in the Eocene (40.1 mya) followed by differentiation of Allieae in the early Miocene (21.3 mya). The split of Gilliesieae from Leucocoryneae was estimated at 16.5 mya. Biogeographic reconstruction suggests an African origin for Allioideae and subsequent spread to Eurasia during the middle Eocene. Cool and arid conditions during the late Eocene led to isolation between African and Eurasian species. African Allioideae may have diverged to South American taxa in the late Oligocene. Rather than vicariance, long-distance dispersal is the most likely explanation for intercontinental distribution of African and South American Allioideae species.

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African Swine Fever (ASF) is a highly infectious viral disease with high mortality. The most recent ASF outbreak in Vietnam occurred in 2019, posing a threat to spread to the neighboring Asian countries. Without a commercial vaccine or efficient chemotherapeutics successfully developed, rapid diagnosis and necessary biosecurity procedures are required to control the disease. While the diagnosis method of ASF recommended by the World Organization of Animal Health is real-time PCR, it is not . CC-BY-NC-ND 4.

The COVID-19, caused by the novel coronavirus SARS-CoV-2, has broken out of control all over the globe and put the majority of the world under lockdown. There have been no specific antiviral medications for SARS-CoV-2 while vaccines are still under development. Thus, rapid diagnosis and necessary public health measures are currently key parts to contain the pandemic. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is the gold standard method for SARS-CoV-2 detection. However, this method is not suitable for point-of-care (POC) diagnosis because of the timeconsuming procedure, the requirements of biosafety conditions and expensive equipment.In this study, the colorimetric isothermal nucleic acid amplification tests (iNAATs) for SARS-CoV-2 based on loop-mediated isothermal amplification (LAMP), cross-priming amplification (CPA), and polymerase spiral reaction (PSR) were developed and compared. The three methods exhibited similar performance with the limit of detection (LOD) as low as just 1 copy per reaction when evaluated on the synthetic DNA fragments. The results can be read with naked eyes within 30 minutes without crossreactivity to closely related coronaviruses. When tested with SARS-CoV-2 extracted genomic-RNA, LAMP outperformed both CPA and PSR assays. Moreover, the direct detection of SARS-CoV-2 in simulated patient samples (oropharyngeal and nasopharyngeal swabs) by colorimetric iNAATs was also successful. Further preparation of the lyophilized reagents for LAMP reactions revealed that the freeze-dried, ready-touse kit maintained the sensitivity and LOD value of the liquid assays. These results strongly indicate that the colorimetric lyophilized LAMP test kit developed herein is highly suitable for detecting SARS-CoV-2 at POC.

Chloroplast genomes (cpDNA) are highly valuable resources for evolutionary studies of angiosperms, since they are highly conserved, are small in size, and play critical roles in plants. Slipped-strand mispairing (SSM) was assumed to be a mechanism for generating repeat units in cpDNA. However, research on the employment of different small repeated sequences through SSM events, which may induce the accumulation of distinct types of repeats within the same region in cpDNA, has not been documented. Here, we sequenced two chloroplast genomes from the endemic species Heloniopsis tubiflora (Korea) and Xerophyllum tenax (USA) to cover the gap between molecular data and explore “hot spots” for genomic events in Melanthiaceae. Comparative analysis of 23 complete cpDNA sequences revealed that there were different stages of deletion in the rps16 region across the Melanthiaceae. Based on the partial or complete loss of rps16 gene in cpDNA, we have firstly reported potential molecular markers for recognizing two sections (Veratrum and Fuscoveratrum) of Veratrum. Melathiaceae exhibits a significant change in the junction between large single copy and inverted repeat regions, ranging from trnH_GUG to a part of rps3. Our results show an accumulation of tandem repeats in the rpl23-ycf2 regions of cpDNAs. Small conserved sequences exist and flank tandem repeats in further observation of this region across most of the examined taxa of Liliales. Therefore, we propose three scenarios in which different small repeated sequences were used during SSM events to generate newly distinct types of repeats. Occasionally, prior to the SSM process, point mutation event and double strand break repair occurred and induced the formation of initial repeat units which are indispensable in the SSM process. SSM may have likely occurred more frequently for short repeats than for long repeat sequences in tribe Parideae (Melanthiaceae, Liliales). Collectively, these findings add new evidence of dynamic results from SSM in chloroplast genomes which can be useful for further evolutionary studies in angiosperms. Additionally, genomics events in cpDNA are potential resources for mining molecular markers in Liliales.

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