Effect of agronomic measures on population dynamics of sweet potato stem nematode (<I>Ditylenchus destructor</I>)

Studies were conducted to evaluate the effectiveness of endosulfan in reducing the incidence of lettuce infectious yellows virus (LIYV) in late-summer planted cantaloupe, Cucumis melo L., through reduction of sweet potato whitefly, Bemisia tabaci (Gennadius), densities. Counts of B. tabaci adults and immatures and of a native parasitoid of B. tabaci, Eretmocerus sp. near californicus Howard (Hymenoptera: Aphelinidae) were lower in treated plots than those in untreated plots for the duration of the trial. Despite lower populations of B. tabaci, LIYV was not significantly different between treatments, reaching 48% in treated and 40% in untreated plots. B. tabaci emigrated out of treated plots which may have contributed to the spread of LIYV. Sooty mold growth on fruit contaminated with B. tabaci-produced honeydew was present on only 0.4% of the melons in treated plots, but on 29% of the melons in the untreated plots. B. tabaci population dynamics on cantaloupe is discussed with regard to control strategies and LIYV epidemiology.

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Resistance to Ditylenchus destructor Infection in Sweet Potato by the Expression of Small Interfering RNAs Targeting unc-15, a Movement-Related Gene

Phytopathology ◽

10.1094/phyto-04-15-0087-r ◽

2015 ◽

Vol 105 (11) ◽

pp. 1458-1465 ◽

Cited By ~ 8

Author(s):

Weijuan Fan ◽

Zhaorong Wei ◽

Min Zhang ◽

Peiyong Ma ◽

Guiling Liu ◽

...

Keyword(s):

Transgenic Plants ◽

Sweet Potato ◽

Ipomoea Batatas ◽

Muscle Protein ◽

Nematode Resistance ◽

Small Interfering Rnas ◽

Storage Roots ◽

Transgenic Lines ◽

Food Security And Nutrition ◽

Ditylenchus Destructor

Stem nematode (Ditylenchus destructor) is one of most serious diseases that limit the productivity and quality of sweet potato (Ipomoea batatas), a root crop with worldwide importance for food security and nutrition improvement. Hence, there is a global demand for developing sweet potato varieties that are resistant to the disease. In this study, we have investigated the interference of stem nematode infectivity by the expression of small interfering RNAs (siRNAs) in transgenic sweet potato that are homologous to the unc-15 gene, which affects the muscle protein paramyosin of the pathogen. The production of double-stranded RNAs and siRNAs in transgenic lines with a single transgene integration event was verified by Northern blot analysis. The expression of unc-15 was reduced dramatically in stem nematodes collected from the inoculated storage roots of transgenic plants, and the infection areas of their storage roots were dramatically smaller than that of wild-type (WT). Compared with the WT, the transgenic plants showed increased yield in the stem nematode-infested field. Our results demonstrate that the expression of siRNAs targeting the unc-15 gene of D. destructor is an effective approach in improving stem nematode resistance in sweet potato, in adjunct with the global integrated pest management programs.

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Population Dynamics of Whitefringed Beetle (Coleoptera: Curculionidae) on Sweet Potato in Alabama

Environmental Entomology ◽

10.1093/ee/26.4.727 ◽

1997 ◽

Vol 26 (4) ◽

pp. 727-735 ◽

Cited By ~ 9

Author(s):

Geoffrey W. Zehnder

Keyword(s):

Population Dynamics ◽

Sweet Potato

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Impact of low-cost management techniques on population dynamics of plant-parasitic nematodes in sweet potato

Crop Protection ◽

10.1016/j.cropro.2020.105311 ◽

2020 ◽

Vol 137 ◽

pp. 105311

Author(s):

Hellen Maina ◽

Hannah Karuri ◽

Felix Rotich ◽

Franklin Nyabuga

Keyword(s):

Population Dynamics ◽

Sweet Potato ◽

Cost Management ◽

Low Cost ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Management Techniques ◽

Plant Parasitic

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Attractant and repellent effects of sweet potato root exudates on the potato rot nematode, Ditylenchus destructor

Nematology ◽

10.1163/15685411-00002856 ◽

2015 ◽

Vol 17 (1) ◽

pp. 117-124 ◽

Cited By ~ 11

Author(s):

Zhen Xu ◽

Yong-Qiang Zhao ◽

Dong-Jing Yang ◽

Hou-Jun Sun ◽

Cheng-Ling Zhang ◽

...

Keyword(s):

Sweet Potato ◽

Root Exudates ◽

Host Location ◽

Field Experiments ◽

Control Method ◽

Northern Region ◽

Effective Control ◽

Potato Plants ◽

Seedling Roots ◽

Ditylenchus Destructor

Potato rot nematode (Ditylenchus destructor) is one of the most damaging pests of sweet potato in the northern region of China. Glasshouse and field experiments were conducted to explore the main invasion route used by potato rot nematodes during infection of sweet potato plants. The nematode’s host location behaviour was also investigated. Results suggested that substantial yield losses of sweet potato caused by D. destructor parasitism depend upon the existence of wounds on seedling roots. Therefore, reducing the number of nematodes that invade through such wounds would be an effective control method. We found that root exudates and extracts from underground stems of both resistant (cv. Zhenghong 22) and susceptible (cv. Lizixiang) sweet potato cultivars attracted potato rot nematodes. In addition, a strong repellent effect of latex against these nematodes was observed in both cultivars. Interestingly, octadecyl-(Z)-p-coumarate, a component of sweet potato latex, acted as a repellent for potato rot nematodes, while hexadecyl- and eicosyl-(Z)-p-coumarates did not. These findings provide a basis for understanding the mechanism underlying the host location behaviour of potato rot nematodes and can help in designing new nematode control methods.

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