The purposes of this paper are to clarify the taxonomic status of the fig-pollinating wasp associateSchistonchussensu lato(Nematoda: Aphelenchoididae) and to suggest directions for future research on the systematics, life history and ecology of the group. Molecular phylogenetic analyses suggest thatSchistonchus s.l.is polyphyletic, and the composition of the three major clades is outlined, together with information on nematode morphology, plant host species, associated pollinating wasp species, and distribution. Biological information and collection data is presented forSchistonchus s.l.fromFicussycones (Moracea) in Africa, Australia, Asia and Central America, and its putative phylogeny is discussed based on molecular and morphological evidence. Both wasps and figs are millions of years old and have worldwide distribution in tropical areas,i.e., opportunities forSchistonchus s.l.-like nematodes to have evolved could have occurred more than once. In addition, figs and their pollinating wasps have variable life histories, which could have provided opportunities forSchistonchus s.l.to also develop different life histories. However, these histories occur inside fig sycones and in association with wasps, which has apparently led to evolutionary convergence and extreme morphological conservatism. Diagnostic characters and their states, derived from examination of described species and morphospecies ofSchistonchus s.l.and informed by molecular phylogenetic inferences, are discussed and illustrated.Schistonchus sensu strictois redefined, andFicophagusn. gen. andMartinineman. gen. are proposed.Schistonchus s.s.is morphologically characterised by having the excretory pore opening in the region of, or posterior to, the metacorpus;Ficophagusn. gen. by having the excretory pore opening very near the cephalic region; andMartinineman. gen. by having it opening at the anterior end of the metacorpus. Several species ofSchistonchus s.s.have a labial disc, but there is no evidence of this in eitherFicophagusn. gen. orMartinineman. gen.
A checklist of Schistonchus collected from Ficus spp. in Australia and stored in the Waite Nematode Collection at the University of Adelaide is presented. Within Australia, Schistonchus contains 12 morphospecies and four nominal species, based on a combination of the following characters: body shape when heat-relaxed, position of excretory pore, length of post-uterine sac, spicule form, and number and position of caudal papillae. Up to four morphospecies of Schistonchus have been collected from one species of Ficus and, in several cases, one morphospecies of Schistonchus has been collected from more than one host fig species. A phylogenetic tree based on D2/D3 sequences showed that Australian collections of Schistonchus fall into two clades, suggestive of endemic and introduced lineages with host switching. Schistonchus aculeata sp. n. is described from F. aculeata and F. opposita and differentiated from other species of Schistonchus by having the excretory pore opening near the lips, a short post-uterine sac, rosethorn-shaped spicules, arcuate gubernaculum or thickening of dorsal wall, amoeboid sperm, and three pairs of caudal papillae (one pair adcloacal, one just posterior to mid-tail, and one near the tail tip), association with Kradibia spp. pollinating wasps and apparent biogeographical range. A key to the known species and morphospecies of Schistonchus from Australia is presented.
Tomato flowers (Solanum lycopersicum L.) in greenhouses require assisted pollination. Compared with pollination using a vibration wand, pollination by buzz pollinating bees results in improved seed set and consequently, higher fruit weight. We investigated whether there are further chemical and sensory differences between bee- and wand-pollinated cherry tomatoes, Solanum lycopersicum variety Conchita. The pollination method did not result in significant differences in concentration of soluble solids and titratable acidity. However, the concentration of soluble solids was significantly positively correlated with seed number. We suggest that an increase in the amount of soluble solids in the locular area, due to increased seed numbers, is counteracted by the effects of seed numbers on the growth of the walls, which occurs through cell elongation. In the sensory part of this study, a large, untrained panel significantly preferred bee-pollinated over wand-pollinated tomatoes and classified bee-pollinated tomatoes as having more depth of flavor than wand-pollinated tomatoes. Thus, bee-pollinated tomatoes taste better than wand-pollinated tomatoes, and it is likely that the sensory differences between the two groups of tomatoes are mediated through effects of pollination treatment on seed numbers. Future chemical and sensory studies of fresh tomatoes should take into account the effects of seed numbers and their possible effect on the distribution of chemical compounds within tomatoes.
Summary Ficophagus from collecting trips in eastern Australia, made over 15 years, are summarised and show that species of the genus occurred widely in sycones of Ficus, subgenus Urostigma, section Malvanthera. Two new species (based on morphological differences and molecular sequencing) are described: Ficophagus elizabethae sp. n. from Ficus macrophylla, F. rubiginosa and F. obliqua, and Ficophagus richardi sp. n. from Ficus obliqua; and a morphospecies, Ficophagus Morphospecies malandicus from Ficus obliqua. Ficophagus elizabethae sp. n. is characterised by having the excretory pore (EP) opening from the level of the junction of the conus and shaft of the stylet to that of the knobs, a relatively long procorpus (1.0-2.5 times length of stylet), female tail with an obliquely truncate tail with a hyaline area and a finely to broadly rounded tip which may be mucronate; post-vulval uterine sac (PUS) ca one vulval body diam. (VBD) in length; rose-thorn-shaped spicule with distinct rostrum and prominent condylus; and genital papillae arranged as largest pair adcloacal, second pair posterior to mid-tail length, and third small pair near tail tip; and was collected from Sydney in New South Wales, to Bundaberg in Queensland (QLD). Ficophagus richardi sp. n. is characterised by having the EP opening at the level of the junction of the stylet shaft and conus, a labial cap which is raised around the opening for the stylet; procorpus 0.8-1.7 times length of the stylet, PUS <1 VBD in length, long uterus, and female tail with a V-shaped hyaline area at the bluntly rounded tip; rose-thorn-shaped spicule with a small rostrum and prominent condylus, three pairs genital papillae, first and largest on anterior cloacal lip, second at 70% of tail length measured from cloacal aperture, and third near tip, and was collected from Ban Ban Springs in the south to the Bundaberg region in the mid-north of QLD. In addition, in the absence of pertinent molecular sequences, a morphospecies is described. Ficophagus Morphospecies malandicus is characterised by having the EP opening anterior to the junction of the stylet conus and shaft, procorpus 0.9-2 times length of stylet, a short PUS usually <1 VBD long, short uterus, rose-thorn-shaped spicule with a raised condylus and prominent rostrum, and three pairs of subventral papillae on the tail (one adcloacal, one posterior to mid-tail and one near tail tip); and was collected from the Atherton Tableland, QLD. A table comparing morphological characteristics is provided to help with identification of Ficophagus nematodes from figs of the section Malvanthera in eastern Australia.
Three new species of Schistonchus were recovered from sycones of Ficus racemosa, F. hispida and F. variegata (Moraceae Subgenus Sycomorus, Section Sycomorus) from the Cairns region in north-eastern Australia. Schistonchus baculum sp. n. is described from F. racemosa and F. hispida and is differentiated from other species of Schistonchus by a combination of morphological characters including having males with a walking-stick shape, excretory pore opening at the anterior end of the metacorpus, a long post-uterine sac, rose-thorn-shaped spicules, no gubernaculum, two pairs of subventral papillae on the tail, DNA sequence data, and apparent biogeographical range. Schistonchus fleckeri sp. n. is described from F. racemosa, F. hispida and F. variegata and is differentiated by a combination of morphological characters, including a C-shaped female and C-shaped to spiral males, the excretory pore opening near the lips, a short to medium length post-uterine sac, slender sickle-shaped spicules with a reduced rostrum, no gubernaculum, three pairs of subventral papillae on the tail, and apparent biogeographical range. Schistonchus cassowaryi sp. n. is described from F. variegata and is differentiated by a combination of morphological characters, including having C-shaped males and females, a posterior excretory pore situated posterior to the nerve ring, a short to medium length post-uterine sac, rose-thorn-shaped spicules, three pairs of subventral papillae on the tail (one adcloacal, one at mid-tail near lateral, and one near the tip), DNA sequence data, and apparent biogeographical range.
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