The multiplication of Longidorus elongatus (de Man) on different host plants with reference to virus transmission

1967 ◽  
Vol 59 (2) ◽  
pp. 275-281 ◽  
Author(s):  
C. E. TAYLOR
Keyword(s):  
Host Plants ◽  
Virus Transmission ◽  
De Man ◽  
Longidorus Elongatus

scholarly journals Aphid endosymbiont facilitates virus transmission by modulating the volatile profile of host plants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiao-Bin Shi ◽  
Shuo Yan ◽  
Chi Zhang ◽  
Li-Min Zheng ◽  
Zhan-Hong Zhang ◽  
...  
Keyword(s):  
Host Plants ◽  
Green Peach Aphid ◽  
Virus Transmission ◽  
Feeding Preference ◽  
Plant Viruses ◽  
Volatile Profile ◽  
Cmv Infection ◽  
Buchnera Aphidicola ◽  
Plant Volatile ◽  
Volatile Profiles

Abstract Background Most plant viruses rely on vectors for their transmission and spread. One of the outstanding biological questions concerning the vector-pathogen-symbiont multi-trophic interactions is the potential involvement of vector symbionts in the virus transmission process. Here, we used a multi-factorial system containing a non-persistent plant virus, cucumber mosaic virus (CMV), its primary vector, green peach aphid, Myzus persicae, and the obligate endosymbiont, Buchnera aphidicola to explore this uncharted territory. Results Based on our preliminary research, we hypothesized that aphid endosymbiont B. aphidicola can facilitate CMV transmission by modulating plant volatile profiles. Gene expression analyses demonstrated that CMV infection reduced B. aphidicola abundance in M. persicae, in which lower abundance of B. aphidicola was associated with a preference shift in aphids from infected to healthy plants. Volatile profile analyses confirmed that feeding by aphids with lower B. aphidicola titers reduced the production of attractants, while increased the emission of deterrents. As a result, M. persicae changed their feeding preference from infected to healthy plants. Conclusions We conclude that CMV infection reduces the B. aphidicola abundance in M. persicae. When viruliferous aphids feed on host plants, dynamic changes in obligate symbionts lead to a shift in plant volatiles from attraction to avoidance, thereby switching insect vector’s feeding preference from infected to healthy plants.

DAMAGE TO FLUE-CURED TOBACCO BY THE NEEDLE NEMATODE LONGIDORUS ELONGATUS

1973 ◽  
Vol 53 (3) ◽  
pp. 689-692 ◽  
Author(s):  
C. F. MARKS ◽  
J. M. ELLIOT
Keyword(s):  
Zea Mays L ◽  
Sweet Corn ◽  
Triticum Aestivum L ◽  
Control Measures ◽  
Severe Stunting ◽  
Nicotiana Tabacum L ◽  
Secale Cereale L ◽  
De Man ◽  
Longidorus Elongatus ◽  
Specific Control

The ectoparasitic nematode (Longidorus elongatus (de Man 1876) Thorne and Swanger 1936) was associated with severe stunting of flue-cured tobacco (Nicotiana tabacum L.) at Delhi, Ontario in early June 1971. Foliar applications of the nematicide Vydate ((S-methylcarbamoyl)-N-[(methylcarbamoyl oxy)] thioformimidate) to the stunted plants reduced the number of L. elongatus in the soil around the roots but did not improve plant growth. A pot test in a greenhouse indicated that flue-cured tobacco, rye (Secale cereale L.), and winter wheat (Triticum aestivum L.) were poor hosts for the nematode whereas sweet corn (Zea mays L.) and sorghum (Sorghum vulgare Pers.) were good hosts. Apparently, in the field the small numbers of L. elongatus that had been subsisting in the soil had multiplied to damaging levels on a crop of sorghum grown in the previous year. Because of the rare occurrence of Longidorus spp. in soils of the tobacco-growing areas of Ontario and the crop rotation and soil fumigation in use by most growers of flue-cured tobacco, it is unlikely that any specific control measures will be required to prevent damage to tobacco by L. elongatus.

Epidemiology of lettuce necrotic yellows virus in South Australia. III.* Virus transmission parameters, and vector feeding behaviour on host and non-host plants

1974 ◽  
Vol 25 (5) ◽  
pp. 791 ◽  
Author(s):  
DB Boakye ◽  
JW Randles
Keyword(s):  
Latent Period ◽  
Host Plants ◽  
Vascular Tissue ◽  
Virus Transmission ◽  
South Australia ◽  
Continuous Light ◽  
Temperature Dependent ◽  
Sonchus Oleraceus ◽  
Transmission Parameters ◽  
The Mean

When Hyperomyzus lactucae are given acquisition feeds of 24 hr on Sonchus oleraceus infected with lettuce necrotic yellows virus (LNYV) a temperature-dependent latent period must be completed before the virus can be transmitted. The mean duration of latent period is 18.0, 9.2 and 5.4 days at 15, 20 and 28°C respectively. On completion of the latent period, H. lactucae transmit LNYV consistently. Within 24 hr of reaching the fourth instar, nymphs which have developed on virus-infected S. oleraceus are capable of transmitting the virus, adult apterae and alatae transmit more efficiently than nymphs, and the efficiency of transmission is similar for both morphological forms of the aphid. The longer the inoculation feed by viruliferous H. lactucae, the greater are the chances for successful transmission of the virus to either S. oleraceus or lettuce seedlings. The inoculation thresholds are between 5 and 30 min on S. oleraceus and 1–5 min on lettuce. During this time stylets penetrate the epidermal layer only, which indicates that aphids can inoculate without penetrating the vascular tissue. Transovarial transmission has been demonstrated in viruliferous viviparae apterae, but the rate of passage of virus to progeny is low; out of 73 sets of progeny 5 sets acquired LNYV maternally. It appears that nymphs which acquire the virus maternally complete the latent period at or shortly after birth. At 20 and 28°, the longevity of aphids transmitting LNYV is less than that of those not transmitting. When apterous H. lactucae freshly removed from S. oleraceus are allowed to probe on lettuce they generally walk off the plant; however, the tendency to settle in a feeding position is considerably increased when they are 'pretreated' by starving them in continuous light at a lowered relative humidity of 65–70%. Salivary secretions are deposited on the leaves of both S. oleraceus and lettuce when either pretreated or untreated aphids are caged on them. Depth of probing increases with time up to 30 min on both hosts, but after this aphids feeding on lettuce tend to withdraw their stylets. Pretreated H. lactucae given access to 32P-labelled plants took up 17 times more sap from S. oleraceus than from lettuce. ____________________ *Part II, Aust. J. Agric. Res., 22: 231 (1974).

Biotype-dependent secondary symbiont communities in sympatric populations of Bemisia tabaci

2007 ◽  
Vol 97 (4) ◽  
pp. 407-413 ◽  
Author(s):  
E. Chiel ◽  
Y. Gottlieb ◽  
E. Zchori-Fein ◽  
N. Mozes-Daube ◽  
N. Katzir ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Host Plants ◽  
Virus Transmission ◽  
Symbiotic Bacterium ◽  
Infection Frequency ◽  
Sympatric Populations ◽  
Bacterial Composition ◽  
Secondary Symbiont ◽  
Q Biotype ◽  
B Biotype

AbstractThe sweet potato whitefly, Bemisia tabaci, harbors Portiera aleyrodidarum, an obligatory symbiotic bacterium, as well as several secondary symbionts including Rickettsia, Hamiltonella, Wolbachia, Arsenophonus, Cardinium and Fritschea, the function of which is unknown. Bemisia tabaci is a species complex composed of numerous biotypes, which may differ from each other both genetically and biologically. Only the B and Q biotypes have been reported from Israel. Secondary symbiont infection frequencies of Israeli laboratory and field populations of B. tabaci from various host plants were determined by PCR, in order to test for correlation between bacterial composition to biotype and host plant. Hamiltonella was detected only in populations of the B biotype, while Wolbachia and Arsenophonus were found only in the Q biotype (33% and 87% infection, respectively). Rickettsia was abundant in both biotypes. Cardinium and Fritschea were not found in any of the populations. No differences in secondary symbionts were found among host plants within the B biotype; but within the Q biotype, all whiteflies collected from sage harboured both Rickettsia and Arsenophonus, an infection frequency which was significantly higher than those found in association with all other host plants. The association found between whitefly biotypes and secondary symbionts suggests a possible contribution of these bacteria to host characteristics such as insecticide resistance, host range, virus transmission and speciation.

scholarly journals Root parasitic nematodes in nursery plants imported to Finland in 1980

1985 ◽  
Vol 57 (3) ◽  
pp. 155-162
Author(s):  
Sirpa Kurppa
Keyword(s):  
Infected Plant ◽  
Virus Transmission ◽  
Parasitic Nematodes ◽  
Pratylenchus Penetrans ◽  
Root Lesion Nematode ◽  
Root Knot Nematode ◽  
Meloidogyne Spp ◽  
Lesion Nematode ◽  
De Man ◽  
Ditylenchus Destructor

Injurious nematodes were found in 201 of the investigated 670 plant stocks of 42 imported consignments. Infections by quarantine nematodes appeared in 100 stocks of 26 consignments, 15 there of including 3 or more infected plant stocks each. Root knot nematode, Meloidogyne spp., appeared in 81 stocks, i.e. 12 % of the investigated material. The infections were found in 40 plant species, relatively often in barberry, Berberis sp., and in peony, Paeonia sp.. Among garden roses, 26 out of 167 stocks investigated were infected by root knot nematodes. Root lesion nematode, Pratylenchus penetrans (Cobb) Chitwood & Oteifa, of P. convallariae Seinhorst was found in 28 plant stocks, i.e. 4 % of the investigated material. Several Pratylenchus-infected stocks were found among roses, raspberry and barberry. Potato rot nematode, Ditylenchus destructor Thorne, was found in one rose stock and related D. myceliophagus J. B. Goodey in 12 stocks of various plants. Several ectoparasitic species were found in very low numbers. Virus vectors, Trichodorus primitivus (de Man) Micoletzky and T. viruliferus Hooper, were detected in a total of four stocks, but too few for virus transmission tests. The transmissability ofthe detected nematodes was discussed, and the risks of introduction of nematode pests to the country was re-assessed.

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