Yongsan Zeng

Summary: A new nematode species was recovered from the figs of Ficus concinna from Xishuangbanna, Yunnan province, P.R. China. It is described herein as Ficophagus fengi n. sp. and is characterised by possessing the combined characters of a short post-uterine sac (6.4-9.7 μ m or 0.4-0.5 VBD long), an excretory pore located near head, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip without mucron, presence of gubernaculum (apophysis)-like structure, a rose-thorn-shaped spicule without a terminal cucullus, a rostrum with a slightly pointed tip, a conoid female tail with a small finger-like tip, and absence of crustaformeria. Ficophagus fengi n. sp. was separated from other sequenced species by differences in the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with LSU D2-D3 expansion segment sequences suggested that F. fengi n. sp. is clustered in a single highly supported monophyletic clade with F. virens and is sister to F. virens .

Summary: A new species of the genus Ficophagus was recovered from the syconia of Ficus pisocarpa from Xishuangbanna, Yunnan province, China. It is described herein as Ficophagus pisocarpae n. sp. and is characterised by possessing the combined characters of a short PUS (6.4-9.3 μm or 0.3-0.4 VBD long), an excretory pore near the head, presence of crustaformeria, amoeboid sperm, three pairs of subventral papillae on the male tail (one pair just adcloacal (P2), one pair halfway between cloacal aperture and tail terminus (P3a), and one pair near tail tip (P4)), rounded male tail tip without mucron, absence of gubernaculum and rose-thorn-shaped spicule with conical rostrum. Ficophagus pisocarpae n. sp. was differentiated from other sequenced species by the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with the LSU D2-D3 expansion segment sequence suggested that F. pisocarpae n. sp. is clustered in the same highly supported monophyletic clade with F. annulatae, F. benjamina, F. curtipes and F. microcarpus. It differs morphologically from these species in lateral incisure number, EP position, spicule and uterus morphology and some morphometric characters.

Summary: A new species of the genus Ficophagus was recovered from the syconia of Ficus annulata from Xishuangbanna, Yunnan province, China. It is described herein as Ficophagus annulatae n. sp. and is characterised by possessing the combined characters of a short PUS (9-18 μm or 0.3-0.6 VBD long), an excretory pore (EP) located at the level between stylet basal knobs and metacorpus, presence of crustaformeria, amoeboid sperm, three pairs of subventral papillae on the male tail (one pair just adcloacal (P2), one pair halfway between cloacal aperture and tail terminus (P3), and one pair near tail tip (P4)), rounded male tail tip without mucron, absence of gubernaculum and bow-shaped spicule with indistinct rostrum. Ficophagus annulatae n. sp. was differentiated from other sequenced species by the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with the LSU D2-D3 expansion segment sequence suggested that F. annulatae n. sp. is clustered in the same highly supported monophyletic clade with F. benjamina, F. curtipes and F. microcarpus. It differs morphologically from these species in EP position, spicule and uterus morphology, and some morphometric characters.

Summary: A new species of the genus Ditylenchus was recovered from rhizosphere soil of a ‘TifEagle’ hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis (Burtt-Davy)) putting green located at the Pee Dee Research & Education Center, Clemson University, Florence, SC, USA. It is described herein as Ditylenchus dactylonae n. sp. and is characterised by possessing the combined characters of a medium body size (682-815 μm in females; 618-718 μm in males), six incisures at the lateral fields, a delicate stylet (7.6-8.0 μm) with rounded knobs, a bottle-shaped basal pharyngeal bulb (BPB), an excretory pore (EP) near anterior end of BPB, a posteriorly located vulva (V = 78-83%), a reflexed ovary, a uterus with crustaformeria anteriorly and nearly spherical structure posteriorly, a post-vulval uterine sac (30-50% of the vulva-anus distance), an elongate conoid and ventrally bent tail, a tylenchoid spicule (17-18 μm), and a leptoderan bursa. Ditylenchus dactylonae n. sp. was differentiated from other sequenced species by the partial small subunit (SSU) rRNA gene, D2-D3 expansion segments of the large subunit (LSU) rRNA gene and internal transcribed spacer (ITS) rRNA. Phylogenetic analysis revealed that D. dactylonae n. sp. belongs to the D. dipsaci-group, and is sister to D. medicaginis and/or D. ferepolitor based on SSU 18S, LSU D2-D3 and ITS sequences.

Summary: A new species of the genus Ficophagus was recovered from the syconia of Ficus variegata from Shenzhen, Guangdong province, China. It is described herein as Ficophagus giblindavisi n. sp. and is characterised by possessing the longest stylet in males (35.1-45.8 μm) and most lateral incisures (5) of all currently described species in the genus, a short PUS (8.4-11.4 μm or 0.3 VBD long), excretory pore situated at or posterior to the nerve ring, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip with a mucron, absence of gubernaculum and sickle-shaped spicules with a terminal cucullus. Ficophagus giblindavisi n. sp. was differentiated from other sequenced species by the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with the LSU D2-D3 expansion segment sequence suggested that F. giblindavisi n. sp. is clustered in the same highly supported monophyletic clade with F. auriculatae and F. fleckeri.

The turfgrass industry has undergone a rapid development in Guangdong province, China, which has the largest number of golf courses in the country. Recent surveys of turfgrasses in the province revealed five plant-parasitic nematodes that are prevalent: Helicotylenchus dihystera, Mesocriconema xenoplax, Meloidogyne graminis, Hemicriconemoides rosae and Tylenchorhynchus leviterminalis. The most prevalent species are M. xenoplax and M. graminis, found in 60.6% and 27.3% of locations, respectively. These five species are morphologically and morphometrically described. Molecular characterization and phylogenetic analyses using 18S rRNA and the D2-D3 expansion segments of 28S rRNA sequences are provided. This is the first report on molecular characterization and phylogenetic relationships of plant-parasitic nematodes associated with turfgrasses in Guangdong, China. This work was a first step for future study including pathogenicity assay, relationship examination with other pathogens and development of control measures of these turf nematodes to provide more precise and effective management options to turf superintendents.

An emerging threat to agriculture, Meloidogyne enterolobii Yang & Eisenback, 1983, is a tropical species and considered to be the most damaging root-knot nematode (RKN) in the world because of its wide host range, aggressiveness, and ability to overcome resistance to RKN in many crops. It was first detected in the United States on ornamental plants in Florida in 2001 but has since been identified in North Carolina, South Carolina, and Louisiana. Several thousand RKN populations were collected from North Carolina field crops, ornamental plants, and turfgrasses for species identification in the Nematode Assay Laboratory in the North Carolina Department of Agriculture & Consumer Services. From 2006 to 2019, root systems showing galling symptoms were dissected under the microscope, and females were obtained for DNA analysis. When only soil samples were submitted, the second-stage juveniles or males were used instead. Molecular characterization was performed via polymerase chain reaction with species-specific primers and DNA sequencing on the ribosomal DNA 18S-ITS1-5.8S and 28S D2/D3 and mitochondrial DNA CoxII-16S. One hundred thirty-five representative RKN populations from North Carolina were characterized and identified as M. enterolobii. Six populations from China where the species was originally described were included in this study for identity confirmation and comparison. As of December 2019, M. enterolobii has been confirmed from a limited number of fields in 11 North Carolina counties: Columbus, Craven, Greene, Harnett, Johnston, Lenoir, Nash, Pitt, Sampson, Wayne, and Wilson. Currently, M. enterolobii is the most important emerging RKN species in the United States and causes severe damage to agronomic and horticultural crops, especially sweetpotato in North Carolina.

Summary: A new nematode species was recovered from the syconia of Ficus hirta var. roxburghii from Chaozhou, Guangdong, China. It is described herein as Ficophagus chaozhouensis n. sp. and is characterised by possessing the combined characters of a short post-uterine sac, excretory pore located near the head, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip with mucron (occasionally swollen), absence of gubernaculum (or apophysis), a blunt rosethorn-shaped spicule without a terminal cucullus, and a digitate rostrum with a broadly squared tip. Ficophagus chaozhouensis n. sp. was separated from other sequenced species by differences in the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with LSU D2-D3 expansion segment sequences suggested that F. chaozhouensis n. sp. is clustered in the same highly supported monophyletic clade with F. aculeata, F. maxima and F. yoponensis, and is sister to F. aculeata.

Summary: A new nematode species was recovered from the syconia of Ficus curtipes from Xishuangbanna Tropical Botanical Garden, Yunnan, China. It is described herein as Ficophagus curtipes n. sp. and is differentiated from all currently described species in the genus by the possession of a spicule with a ventrally recurved tip (terminal barb). It is further characterised by possessing a short post-uterine sac, an ovoid spermatheca, presence of crustaformeria, excretory pore located near the head, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip without mucron, rose-thorn-shaped spicules without cucullus and absence of gubernaculum (= apophysis). Ficophagus curtipes n. sp. was differentiated from other sequenced species by the partial small subunit rRNA gene and D2-D3 expansion segments of the large subunit rRNA gene. Phylogenetic analyses suggested that F. curtipes n. sp. has a closer relationship with F. benjamina and F. microcarpus in the same highly supported monophyletic clade than to the other sequenced Ficophagus and Schistonchus s.l. species.

Summary: A new nematode species was recovered from the syconia of Ficus auriculata-complex, including F. auriculata, F. oligodon and F. hainanensis, from Xishuangbanna Tropical Botanical Garden, China. It is described herein as Ficophagus auriculatae n. sp. and is characterised by possessing the combined characters of a short post-uterine sac, excretory pore located between the metacorpus and the stylet basal knobs, testis multi-reflexed, amoeboid sperm, three pairs of subventral papillae on male tail, rounded male tail tip without mucron, absence of gubernaculum (= apophysis) and sickle-shaped spicules with terminal cucullus. Ficophagus auriculatae n. sp. was differentiated from other sequenced species by the partial small subunit rRNA gene and D2-D3 expansion segments of the large subunit rRNA gene. Phylogenetic analysis with the above-mentioned sequences suggested that F. auriculatae n. sp. has a closer relationship with F. fleckeri in the same highly supported monophyletic clade than with the other sequenced Ficophagus and Schistonchus sensu lato species.