Genetic divergence and migration patterns of a galatheoid squat lobster highlight the need for deep-sea conservation.

Information on genetic divergence and migration patterns of vent- and seep-endemic macrobenthos can help delimit biogeographical provinces and provide scientific guidelines for deep-sea conservation under the growing threats of anthropogenic disturbances. Nevertheless, related studies are still scarce, impeding the informed conservation of these hotspots of deep-sea biodiversity. To bridge this knowledge gap, we conducted a population connectivity study on the galatheoid squat lobster Shinkaia crosnieri - a deep-sea foundation species widely distributed in vent and seep ecosystems in the Northwest Pacific. With the application of an interdisciplinary methodology involving population genomics and oceanographic approaches, we unveiled two semi-isolated lineages of S. crosnieri with limited and asymmetrical gene flow potentially shaped by the geographic settings, habitat types, and ocean currents - one comprising vent populations in the Okinawa Trough, with those inhabiting the southern trough area likely serving as the source; the other being the Jiaolong (JR) seep population in the South China Sea. The latter might have recently experienced a pronounced demographic contraction and exhibited genetic introgression from the Okinawa Trough lineage, potentially mediated by the intrusion of the North Pacific Intermediate Water. We then compared the biogeographic patterns between S. crosnieri and two other representative and co-occurring vent- and seep-endemic species using published data. Based on their biogeographical subdivisions and source-sink dynamics, we highlighted the southern Okinawa Trough vents and the JR seep warrant imperative conservation efforts to sustain the deep-sea biodiversity in the Northwest Pacific.

First Report of Root Rot on Paris polyphylla var. yunnanensis caused by Fusarium solani in Yunnan, China.

Paris polyphylla var. yunnanensis is a perennial herb with diverse chemical components having wide-ranging pharmacological effects. The demand for P. polyphylla var. yunnanensis as a raw material increases greatly and currently exceeds 1,000 tons per year (Zhou et al. 2021). In September 2021, root rot was observed on P. polyphylla var. yunnanensis in Mangshi, Yunnan province, China. Average disease incidences in the fields reached 15%, with diseased plants exhibiting yellowing and wilting leaves, as well as browning and rotting roots. Cross sections (5 × 5 mm2) cut from the margin of symptomatic and asymptomatic root tissues were surface-sterilized for 30 s with 75% ethanol, followed by 180 s with 1% sodium hypochlorite. After rinsing thrice with sterile distilled water, the fragments were transferred to potato dextrose agar (PDA) plates and incubated at 28°C in the dark. Ten isolates were obtained, and single spore isolation was performed. These isolates showed similar morphological characters, with colonies ranging in color from white to pale cream and sparse mycelia. Conidia were produced on the top or side of phialides. Microconidia were oval or reniform, 0- or 1-septate, with a diameter of 5.1-10.7 µm × 1.6-3.9 µm (average 7.6 µm × 2.8 µm) (n=30). The macroconidia were straight to slightly curved or sickle-shaped, 3- to 5-septate, with a diameter of 15.1-27.9 µm × 2.8-4.0 µm (average 21.0 µm × 3.6 µm). Chlamydospores were smooth, nearly round, and 3.3-6.6 (average 4.9) µm in diameter. Genomic DNA were extracted from mycelia of the two isolates. The nuclear ribosomal internal transcribed spacer (ITS), translation elongation factor 1 alpha (EF1α), and the second largest subunit of nuclear DNA-directed RNA polymerase II (RPB2) were amplified with the primer pairs of ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. These two isolates exhibited the same nucleotide sequences (ITS, OP646781; EF1α, OP661172; RPB2, OP661173), with BLASTn analyses showing 100%, 99.66%, and 99.65% identity, respectively, with Fusarium solani (syn. Neocosmospora solani) (Crespo et al. 2019) strain NRRL 43474 (ITS, EF453097; EF1α, EF452945; RPB2, EF469984). A phylogenetic tree was constructed using MEGAX based on the nucleotide sequences of ITS, EF1α, and RPB2, using the maximum likelihood method. The isolate was classified into the F. solani clade. According to the morphology and sequence analyses, the isolate was identified as F. solani (Chehri et al. 2015), and named PpFs1. To test the pathogenicity of the isolate PpFs1, the roots of four years old P. polyphylla var. yunnanensis plants were dipped in 107 spore/mL suspension filtered from potato dextrose broth (PDB) for 30 min, while control roots were dipped in sterile water. After inoculation, all plants were transplanted in pots filled with sterile soil and kept at 25°C with a 12/12-h light/darkness photoperiod. Six plants were used for each treatment, and repeated thrice. Two months after inoculation, the infected plants showed wilted leaves and rotted roots, while controls remained asymptomatic. PpFs1, identified by morphology and ITS, was re-isolated from infected plants, and was found to comply with Koch's postulates. To the best of our knowledge, F. oxysporum and F. concentricum causes Paris polyphylla var. Chinensis stem rot in China. But this is the first report of root rot on P. polyphylla var. yunnanensis being caused by F. solani in Yunnan, China.

In-situ construction of Cr2O3@ATO hybrid pigment towards synergetic enhancement of visible light-infrared-radar compatible stealth.

Multiband compatible stealth engineering with controllable visible light-infrared (VIS-IR) features and radar wave absorption is urgently needed to improve the survivability of advanced military equipment. Cr2O3 has good visible light stealth performance under green background, but it is lack of IR and radar multi-band stealth properties. Herein, a core-shelled Cr2O3@stannic antimony oxide (ATO) structure was developed to enhance the IR-radar compatible stealth properties of Cr2O3 by in-situ precipitation method, concurrently maintaining its visible light stealth property. The morphology, conductivity, and infrared stealth properties of the Cr2O3@ATO hybrids were influenced by the calcination temperature, and the IR and radar stealth performance were tunable by ATO content. The lowest emissivity of Cr2O3@ATO pigments is 0.852, reduced by 10% than pure Cr2O3. The Cr2O3@ATO filled silicone resin coatings possessed good thermal stability and IR stealth stability. Benefiting from the enhanced interfacial polarization and conductive loss, the Cr2O3@ATO exhibited an effective absorption bandwidth of 2 GHz in the X band, with respect to pure Cr2O3 without radar absorption property. The Cr2O3@ATO structure opens an avenue for advanced VIS-IR-Radar compatible stealth materials.

First Report of Collar Rot in Purple Passion Fruit (Passiflora edulis) Caused by Neocosmospora solani in Yunnan province, China.

Purple passion fruit (Passiflora edulis Sims) is a perennial climbing vine native to South America that is grown worldwide as an edible tropical fruit with excellent nutritional value and high economic value (Zibadi et al. 2007). With the increasing expansion of the plantation area in China, considerable economic loss caused by collar rot has attracted wide attention. From 2018-2020, collar rot resulted in the death of many plants of P. edulis 'Mantianxing', a commercial cultivar in China, in southwest China's Yunnan province. The disease spread quickly, and field incidence reached more than 50%. Stem rot symptoms were observed at the base of the stem, about 5-10 cm from the ground, resulting in wilting, defoliation, and death of plants. Representative symptomatic samples were collected from the base of five plants, surface disinfested for 30 seconds with 75% ethanol and 15 min with 10% hypochlorite, washed three times with sterile distilled water, then transferred to potato dextrose agar (PDA) dishes. After 2 days in the dark at 28℃, emerging fungal colonies were purified on new PDA dishes cultured at 28℃ for 7 days. The mycelia were flocculent. The color of the surface and the reverse colony was white and cream, respectively. On synthetic nutrient agar (SNA) medium, microconidia were oval, ellipsoidal or reniform, 0- or 1-septate, and 6.7-23.1 µm in length (n>30); macroconidia were straight to slightly curved, 3- or 5-septate, and 30.8-53.9 µm in length (n>30). Genomic DNA, extracted from six isolates, was amplified with three pairs of primers, ITS1 and ITS4 (White et al. 1990) , EF1-728F and EF1-986R (Carbone and Kohn 1999), and fRPB2-5F and fRPB2-7cR (Liu et al. 1999). The amplicons from all six isolates were sequenced and identical sequences obtained. The sequence of one representative isolate was uploaded to NCBI (National Center for Biotechnology Information) and analyzed with BLASTn in the Fusarium MLST database (https://fusarium.mycobank.org). The sequence of the internal transcribed spacer 1 (ITS1) region (GenBank MN944550) showed 99.1% (449/453 bp) identity to Fusarium solani strain NRRL 53667 (syn: Neocosmospora solani, GenBank MH582405). The sequence of the translation elongation factor-1 (EF-1) gene (GenBank MN938933) showed 97.8% identity (263/269 bp) to F. solani strain NRRL 32828 (GenBank DQ247135). The sequence of the second largest subunit of RNA polymerase Ⅱ (RPB2) gene (GenBank MW002686) showed 98.7% identity (810/821 bp) to F. solani strain NRRL 43441 (GenBank MH582407). Based on a multilocus phylogenetic analysis of the ITS1, EF-1 and RPB2 sequences, coupled with the morphological characteristics, the isolate (designated as NsPed1) was considered to be Neocosmospora solani (syn: Fusarium solani) (Crespo et al. 2019). Subsequently, three-month-old healthy seedlings and 45-day-old cuttings of P. edulis 'Mantianxing' plants were inoculated with the isolate NsPed1 to test its pathogenicity. Stems were wounded, approximately 1-2 mm deep, in the collar region of plants at 2 cm above the soil. A disk (9 mm in diameter) of NsPed1-colonized PDA was placed on the wound. Sterile PDA served as controls. All plants were kept in a growth chamber with 28-30°C, 60% relative humidity, and 16/8-h light/dark photoperiod. Fifteen plants were used for each treatment and replicated three times. Two weeks after inoculation, the stems of the inoculated plants turned brown with a lesion, 2-5 cm in length, and the leaves wilted. These symptoms were similar to those of the diseased plants in the field. The control plants were asymptomatic. N. solani NsPed1 was re-isolated from the infected plants, satisfying Koch's postulates. Taken together, N. solani NsPed1 was identified as the causal pathogen of collar rot in P. edulis 'Mantianxing'. Knowledge of the causal organism of collar rot in purple passion fruit will lead to improved measures to prevent and control the disease in China and other countries.

miR172 Regulates both Vegetative and Reproductive Development in the Perennial Woody Plant Jatropha curcas.

Jatropha curcas is a promising feedstock for biofuel production because its oil is highly suitable for processing bio-jet fuels and biodiesel. However, Jatropha exhibits a long juvenile stage in subtropical areas. miR172, a conserved small non-protein-coding RNA molecule with 21 nucleotides, regulates a wide range of developmental processes. To date, however, no studies have examined the function of miR172 in Jatropha. There are five miR172 precursors encoding two mature miR172s in Jatropha, which are expressed in all tissues, with the highest expression level in leaves, and the levels are up-regulated with age. Overexpression of JcmiR172a resulted in early flowering, abnormal flowers, and altered leaf morphology in transgenic Arabidopsis and Jatropha. The expression levels of miR172 target genes were down-regulated, and the flower identity genes were up-regulated in the JcmiR172a-overexpressing transgenic plants. Interestingly, we showed that JcmiR172 might be involved in regulation of stem vascular development through manipulating the expression of cellulose and lignin biosynthesis genes. Overexpression of JcmiR172a enhanced xylem development and reduced phloem and pith development. This study helped elucidate the functions of miR172 in perennial plants, a known age-related miRNA involved in the regulation of perennial plant phase change and organ development.