scholarly journals Penetration and post-infection development of root-knot nematodes in watermelon

2018 ◽  
Vol 15 (4) ◽  
pp. e1010 ◽  
Author(s):  
Manuel López-Gómez ◽  
Soledad Verdejo-Lucas

Meloidogyne javanica has showed less reproductive success than M. incognita in watermelon genotypes. This study was conducted to elucidate the low reproduction of M. javanica in watermelon. The post-infection development of M. javanica in watermelon ‘Sugar Baby’ was determined at progressively higher initial population (Pi) levels at two time points during the life cycle. Plants were inoculated with 0, 25, 50, 100, 200, and 300 second-stage juveniles (J2)/plant. The increase in Pi was correlated with the penetration rates (R2= 0.603, p<0.001) and total numbers of nematodes in the root (R2 =0.963, p< 0.001) but there was no correlation between the Pi and the reproduction factor (eggs/plant/Pi). The population in the roots at 26 days post-inoculation (dpi) consisted primarily of third-stage juveniles (J3) with a small presence of J2 and fourth stages, and egg-laying females. The dominance of the J3, when egg-laying females are expected, point to the malfunction of the feeding sites that failed to support nematode development beyond the J3 stage. The similarities in egg-laying females at 26 and 60 dpi imply the disruption of the life cycle. Watermelon compensated for M. javanica parasitism by increasing vine length (19% to 33%) and dry top weight (40%) in comparison with the non-inoculated plants. The area under the vine length progress curve was significantly larger as the Pi progressively increased (R²=0.417, p<0.001). Physiological variation was detected between the M. incognita populations. M. arenaria had less ability to invade watermelon roots than did M. incognita and M. javanica.

1989 ◽  
Vol 67 (9) ◽  
pp. 2335-2340 ◽  
Author(s):  
Robert J. A. Laberge ◽  
J. Daniel McLaughlin

The life cycle of Streptocara crassicauda (Creplin, 1829) was studied experimentally in the amphipod Hyalella azteca (Saussure). Of 2946 H. azteca that survived exposure, 699 were infected. Developing larval stages were found almost exclusively in the cephalic haemocoel. At 18–20 °C, moulting first-stage larvae were observed initially on day 11 and moulting second-stage larvae on day 15 post infection. The moult was not synchronous and moulting stages were found for several days after the initial observation. Third-stage larvae were found as early as day 19 post infection. The larval stages found in H. azteca are described. Mature females containing larvated eggs were recovered from domestic ducks (Anas platyrhynchos dom.) 9–21 days post exposure, and eggs were found in fecal samples on day 26. None of the females recovered from ducks 42 days post infection contained larvated eggs.


1992 ◽  
Vol 34 (4) ◽  
pp. 277-287 ◽  
Author(s):  
Dulcinéa Maria Barbosa Campos ◽  
Lindomar G. Freire Filha ◽  
Miguel Alípio Vieira ◽  
Julieta Machado Paçô ◽  
Moacir A. Maia

The life cycle of Lagochilascaris minor was studied using material collected from human lesion and applying the experimental model: rodents (mice, hamsters), and carnivorae (cats, dogs). In mice given infective eggs, orally, hatch of the third stage larvae was noted in the gut wall, with migration to liver, lungs, skeletal musculature and subcutaneous tissue becoming, soon after, encysted. In cats infected with skinned carcasses of mice (60 to 235 days of infection) it was observed: hatch of third stage larvae from the nodules (cysts) in the stomach, migration through the oesophagus, pharynx, trachea, related tissues (rhino-oropharynx), and cervical lymphonodes developing to the mature stage in any of these sites on days 9-20 post inoculation (P.I.). There was no parasite development up to the mature stage in cats inoculated orally with infective eggs, which indicates that the life cycle of this parasite includes an obligatory intermediate host. In one of the cats (fed carcass of infected mice) necropsied on day 43 P.I., it was observed the occurence of the self-infective cycle of L. minor in the lung tissues and in the cervical region which was characterized by the finding of eggs in different stages of development, third stage larvae and mature worms. It's believed that some component of the carnivorae gastrointestinal tracts may preclude the development of third stage larvae from L. minor eggs what explains the interruption of the life cycle in animals fed infective eggs. It's also pointed out the role of the intermediate host in the first stages of the life cycle of this helminth.


Author(s):  
Angélica Miamoto ◽  
Andressa Cristina Zamboni Machado ◽  
Orazília França Dorigo ◽  
Thaísa Muriel Mioranza ◽  
Heriksen Higashi Puerari ◽  
...  

Root-knot nematodes are obligate parasites, so changes at their feeding sites can limit their development. Alterations to feeding sites is one of the main actions taken by antagonistic plants. The aim of this study was to assess the response and histopathology of interactions between Meloidogyne javanica and the roots of Macrotyloma axillare cv. Java. The penetration and development of the nematode was assessed from 8 to 30 days after inoculation (DAI) with 3000 eggs + second-stage juveniles (J2) of M. javanica. The reproduction factor (RF) was assessed at 60 DAI, with two inoculation levels, 700 and 1000 eggs + J2, and the changes in the development and histopathology of M. javanica was assessed at 10, 15 and 30 DAI. Suscetible soybean was used as a control. The development of nematodes at the third (J3) and fourth juvenile (J4) stages was delay, despite the presence of J2 inside the roots, and no adult females were found in the M. axillare cv. Java roots. RF was 0.31 and 0.39 for M. axillare cv. Java and 3.40 and 4.52 for soybean at inoculation levels of 700 and 1000 eggs + J2, respectively. The feed cells in M. axillare cv. Java could not effectively nourish the nematode, which led to deformed females 30 DAI. The feed cells and nematode development, however, were normal in soybean. M. axillare cv. Java was resistant to M. javanica and had an antagonistic potential, because it did not prevent the nematode from penetrating the roots but had a negative effect on M. javanica due to the inefficiency of the feeding site.


2013 ◽  
Vol 31 (4) ◽  
pp. 618-621 ◽  
Author(s):  
Silvia Renata S Wilcken ◽  
Juliana MO Rosa ◽  
Juliana N Westerich ◽  
Maria José de M Garcia ◽  
Antonio Ismael Inácio Cardoso

This study aimed to determine the resistance of six rootstocks for cucumber (squash 'Menina Brasileira', pumpkin 'Exposição', 'Shelper', 'Tetsukabuto Takaiama', 'B8-A Tetsukabuto' and 'Excite Ikki') and four Japanese cucumber hybrids ('Yoshinari', 'Kouki', 'Taisho' and 'Tsuyataro') to Meloidogyne enterolobii. The experiment was conducted in greenhouse; each plot consisted of one plant per pot containing 2 liters of autoclaved soil. The experimental design was completely randomized, with five replicates per treatment. Two days after transplanting the seedlings, each plant was inoculated with 5,000 eggs and second-stage juveniles (initial population = Pi) of M. enterolobii. Tomato 'Rutgers' was used as indicative of inoculum viability. Sixty days after inoculated, each plant was evaluated for total number of nematodes in the roots (final population = Pf) and reproduction factor (FR=Pf/Pi). All rootstocks and cucumber hybrids allowed M. enterolobii multiplication, but FR values were lower in 'Shelper', 'Excite Ikki KY' and 'Menina Brasileira' rootstocks. In a second experiment, the low FR in these three rootstocks was confirmed, but with higher values in 'Menina Brasileira'. So, these rootstocks can be recommended to M. enterolobii infested areas, but with low populations, because they don't permit great multiplication of the patogen. It is concluded that 'Shelper' and 'Excite Ikki KY' rootstocks had the lowest FR and can be classified as moderate resistant to this nematode.


Nematology ◽  
2012 ◽  
Vol 14 (4) ◽  
pp. 405-415 ◽  
Author(s):  
Ma. Teodora Nadong Cabasan ◽  
Arvind Kumar ◽  
Dirk De Waele

Migration, penetration, development and reproduction of the rice root-knot nematode, Meloidogyne graminicola, in the resistant African rice genotypes TOG5674, TOG5675, CG14 and RAM131, and in the susceptible Asian rice genotypes IR64 and UPLRi-5 were studied and compared. The number of second-stage juveniles (J2) that had migrated horizontally and vertically towards the rhizosphere at 48 h after inoculation was comparable in both resistant and susceptible rice genotypes. Penetration of J2 was significantly lower in the resistant rice genotypes compared with the susceptible rice genotypes at 3 and 7 days after inoculation (DAI). Nematode development in the resistant rice genotypes was slower than in the susceptible rice genotypes. Nematode reproduction was significantly lower in the resistant rice genotypes, which supported fewer eggs per g of roots and eggs per female. A significantly higher percentage of egg-laying females was found in the susceptible rice genotypes. Mature females that had developed in the resistant rice genotypes were significantly smaller than the ones in the susceptible rice genotypes. The resistant rice genotypes had significantly fewer galls than the susceptible rice genotypes.


2000 ◽  
Vol 74 (4) ◽  
pp. 323-328 ◽  
Author(s):  
M. Køie

AbstractMature specimens of Cucullanus heterochrous Rudolphi, 1802 (Nematoda: Cucullanidae) were obtained from the intestine of the flounder, Platichthys flesus, from Danish waters. Eggs embryonate in seawater but do not hatch. Fully developed larvae pressed out of eggs are 430 μm long with amphids and dereids and enclosed within the cuticle of a previous larval stage. Infective larvae are believed to be in their third stage. Experimental studies showed that the polychaetes, Nereis spp., Scoloplos armiger, Brada villosa and Capitella sp., may act as intermediate hosts. In N. diversicolor the larvae increase their length to 1 mm within four weeks (15°C) without moulting. Experimental infections showed that larvated eggs are not infective to fish, whereas >550 μm long larvae from polychaetes survived in 4–24 cm long flounders and plaice, Pleuronectes platessa. Third-stage larvae 550 μm to 1.1 mm long were found in the submucosa of the intestine one week post infection. At a length of about 800 μm to 1.4 mm they moult to fourth-stage larvae. Fourth-stage larvae, immature and mature worms occur in the intestine and rectum. Fourth-stage larvae and adults survived experimental transfer from one flounder to another. Similar developmental stages survived for two weeks in the intestine of experimentally infected cod, Gadus morhua.


1971 ◽  
Vol 45 (4) ◽  
pp. 341-352 ◽  
Author(s):  
J. M. Goldsmid

The life cycle and biology of T. deminutus were studied and investigations were carried out on the site of infection in the host, the female to male ratio, the egg laying capacity of the female worms, the development of the eggs after leaving the host and preliminary observations on the effects of desiccation and low temperatures on the third stage larvae were made.


Nematology ◽  
2010 ◽  
Vol 12 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Ayako Hirao ◽  
Ralf-Udo Ehlers ◽  
Olaf Strauch

Abstract The life cycle and population dynamics of the entomopathogenic nematodes Steinernema carpocapsae and S. feltiae were studied in monoxenic liquid culture with their symbiotic bacteria Xenorhabdus nematophila and X. bovienii. To distinguish between the different juvenile and adult stages, their size was recorded. No differences were observed between the species in the size of the juvenile stages but significant differences were recorded in the length of the F1 adults, pre-dauer (J2d) and dauer juvenile stages (DJ). On average, 90% of inoculated DJ of S. feltiae recovered and 77% of S. carpocapsae. In general, S. feltiae developed from the inoculum DJ to the adult approximately 1 day faster than S. carpocapsae. The sex ratio was female-biased (59.2 ± 2.2% in S. carpocapsae, 66.7 ± 2.6% in S. feltiae) in the parental population but not in the F1 generations. Steinernematid adults, like heterorhaditids, respond to depleting food resources with the cessation of egg laying. Juveniles hatch inside the uterus and develop at cost of the maternal body content causing the death of the adult (endotokia matricida). In contrast to Heterorhabditis spp. and in vivo observations of steinernematids by other authors, who reported that readily developed DJ leave the carcass of the dead adult, in this study J2d emerged 12 h after cessation of egg laying. The density of both bacterial cultures decreased due to the feeding of the parental juveniles. However, X. nematophila continued at very low density, whereas the density of X. bovienii increased again until 15 days post-inoculation. The vast majority of F1 S. carpocapsae offspring developed to DJ, whereas in S. feltiae a significant second and third generation of adults was observed, probably due to the increasing bacterial population. However, second and third generation adults in S. feltiae cultures did not contribute significantly to the DJ yield. Mean yields of 158 × 103 DJ ml–1 were recorded for S. carpocapsae and 106 × 103 DJ ml–1 for S. feltiae. The results provide valuable information for future process improvement.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Erich W. Zinser ◽  
Tom L. McTier ◽  
Nicole S. Kernell ◽  
Debra J. Woods

Abstract Background The cryopreservation of filarial nematodes has been studied for nearly 70 years. Largely, these studies examined the effectiveness of cryopreservation methods by using the post-thaw survival of microfilariae (mf) and the development to third-stage larvae (L3s) following inoculation into a competent insect vector. Only one study reported complete reestablishment of a filarial nematode (Brugia malayi) life-cycle in a competent vertebrate host from cryopreserved stock. Expanding on this previous research, a cryopreservation method was developed to cryopreserve the mf of the dog heartworm, Dirofilaria immitis. Methods A combination of cryoprotectants, dimethyl sulfoxide (DMSO) and polyvinyl pyrolidone (PVP) at 6% and 4 mM, respectively, provided acceptable post-thaw survival of mf that developed into L3s in Aedes aegypti. L3s developed from cryopreserved and freshly collected mf in mosquitoes were inoculated into ferrets and dogs and were assessed after a sufficient duration post-inoculation for development into adult heartworms. Results Fewer adult heartworms derived from cryopreserved stocks of mf were recovered from ferrets compared to adult heartworms derived from freshly collected mf, and the former were smaller by weight and length. The onset of patency (circulating mf) occurred at similar post-inoculation time points and at similar mf densities in dogs infected with L3s sourced from cryopreserved stocks or freshly collected mf. Adults derived from cryopreserved mf have survived and produced viable mf for more than 3 years in dogs. Approximately 60% of inoculated L3s were recovered as adults from dogs at 2 and 3.5 years post-inoculation. Conclusions The results from these direct comparisons demonstrate that cryopreserved mf can develop into L3s in vector mosquitoes and that these L3s are infective to both dogs and ferrets, where they undergo normal development into adult worms. These worms are able to mate and produce viable mf and complete the heartworm lifecycle in dog. Graphical Abstract


Author(s):  
Leslie Sharon Lozada-Villanueva ◽  
◽  
Teodocia Gloria Casa-Ruiz ◽  
Cristiano Bellé ◽  
◽  
...  

The effect of initial population density (Pi) of the peanut root-knot nematode, Melodoigyne arenaria, on curly leaf parsley growth was assessed in this study. The population densities of M. arenaria ranged from 0 to 64 eggs + second-stage juveniles (J2)/cm3 soil in sterile sandbags. The root gall index (RGI), reproduction factor (RF), fresh leaf weight (FLW), dry leaf weight (DLW), root fresh weight (RFW), root length (RL), leaf height (LH), and chlorophyll index (SPAD) were determined at 90 days after inoculation. FLW, DLW, RFW, LH, and SPAD data were fitted to the Seinhorst equation, y = m + (1 - m) zPi-T, to determine the tolerance limit T = 0.25 eggs +J2/cm3 soil for FLW, DLW, RFW, and LH, with relative means (m) of 0.52, 0.24, 0.22, and 0.4 respectively; conversely, the T value for SPAD was 0.125 eggs + J2/cm3 soil and with a m of 0.26. All biometric variables decreased with an increase in the initial population density (Pi). Nevertheless, the highest RF of M. arenaria in parsley was 78.92 for a Pi = 8 eggs + J2/cm3 soil, with an RGI value of 5 from Pi = 1 eggs + J2/cm3. Curly leaf parsley growth decreased with an increase in Pi of M. arenaria.


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