Sweet Potato (Ipomoea batatas L.) Regeneration and Transformation Technology to Provide Weevil (Cylas formicarius) Resistance. Field Trial Results

Sweet potato Ipomoea batatas (L.) Lam is an important food crop in the world as well as in Vietnam. Despite its many benefits, the production of sweet potato is restricted in many areas of the world by diseases, weed, and, particularly, pests. As an alternative, genetic transformation provides the means for complementing conventional breeding to improve sweet potato to resistant to pest. In this study, shoot tip explants of KB1 sweet potato variety were infected with A. tumefaciens C58 carying pBI101/cry3Ca1 con-struct. The selection were occured on callus producing medium (SM) containing 0.5 g/L picloram, 50 mg/L kanamycin and 500 mg/L cefotaxime. Survival embryogenic calli were then transferred to embryo producing medium (EG2) supplemented with 1.0 mg/L ABA and 1.0 mg/L GA3 after 2–3 weeks. Putative transgenic shoots regenerated on medium (RM) adding 0.5 mg/L kinetin and 1.0 mg/L BAP were rooted on root producing medium (RR). The tentative transgenic lines were proved positively by PCR and finalized by Southern hybridization, and biotest in laboratory. Conclusionly, we obtained 62 tentative transgenic sweet potato lines resistant to kanamycin. Among these lines, five putative transgenic lines were proved positively by Southern hybridization and have one copies of the cry3Ca1 gene. Two of them have the lower degree of infestation by sweet potato weevil (Cylas formicarius) than that of untransformed lines.

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RESISTANCE IN SWEET POTATOES TO THE SWEETPOTATO WEEVIL, CYLAS FORMICARIUS ELEGANTULUS (SUMMERS)1

Journal of Entomological Science ◽

10.18474/0749-8004-20.3.345 ◽

1985 ◽

Vol 20 (3) ◽

pp. 345-350 ◽

Cited By ~ 14

Author(s):

Michael A. Mullen ◽

Alfred Jones ◽

Donald R. Paterson ◽

Thurman E. Boswell

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

The Other ◽

Sweet Potatoes ◽

Sweetpotato Weevil ◽

The Past ◽

Cylas Formicarius ◽

Cylas Formicarius Elegantulus

Fourteen sweet potato [Ipomoea batatas (L.) Lam] cultivars and varieties were examined for resistance to the sweetpotato weevil [Cylas formicarius elegantulus (Summers)] in artificially infested fields in Yoakum, TX. One cultivar W-226, appeared to have a greater level of resistance than the other cultivars examined. The data are compared to earlier resistance trials to show that the germplasm presently available has greater levels of resistance than that in previous years. The resistance levels of “Resisto” and “Regal” for the past 4 years are discussed.

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Reduced Emergence of Cylas formicarius elegantulus (Coleoptera: Curculionidae) from Sweet Potato Roots by Heterorhabditis indica

Journal of Economic Entomology ◽

10.1093/jee/toaa054 ◽

2020 ◽

Vol 113 (3) ◽

pp. 1129-1133

Author(s):

Roxana Y Myers ◽

Charmaine D Sylva ◽

Cathy L Mello ◽

Kirsten A Snook

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

Potato Production ◽

Field Trials ◽

Storage Roots ◽

Heterorhabditis Indica ◽

Cylas Formicarius ◽

Virgin Land ◽

Cylas Formicarius Elegantulus ◽

Cropping Seasons

Abstract Okinawan sweet potato, Ipomoea batatas, is an important food staple and export crop for the Island of Hawaii. Cylas formicarius elegantulus, sweet potato weevil, is a major quarantine pest that causes severe destruction to the crop. Root malformation and a bitter taste occur when larvae feed and tunnel within the storage root. Off-grade roots are often left in the field after harvest and serve as a reservoir for the weevils. Current management involves the unsustainable practice of moving to virgin land for the next cropping cycle. Strains of Heterorhabditis indica isolated from the Hawaiian Islands were tested for their efficacy at causing mortality of C. formicarius and reducing the emergence of adults from infested roots. In well plate assays, H. indica caused mortality of 88% larvae, 96% pupae, and 4% adults after 48 h. When applied to infested roots, the nematodes caused an average mortality of 78% larvae, 66% pupae, and 32% adults. Greater mortality was observed at the highest inoculum levels (10,000 infective juveniles per storage tuber) but a reduction of 90% inoculum density was still effective at weevil management. In simulated field trials, infestation of storage roots was reduced by 42–99.6% when planted among infested roots that had been inoculated with H. indica. Rates of 2.5 billion IJs/hectare were just as effective as 5 billion IJs/hectare. Application of local H. indica strains in sweet potato production has the potential to manage C. formicarius populations and allow for consecutive cropping seasons.

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Origins, Divergence, and Contrasting Invasion History of the Sweet Potato Weevil Pests Cylas formicarius (Coleoptera: Brentidae) and Euscepes batatae (Coleoptera: Curculionidae) in the Asia-Pacific

Journal of Economic Entomology ◽

10.1093/jee/toz198 ◽

2019 ◽

Vol 112 (6) ◽

pp. 2931-2939 ◽

Cited By ~ 1

Author(s):

Dean R Brookes ◽

James P Hereward ◽

Gimme H Walter ◽

Michael J Furlong

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

Insect Pests ◽

Genetic Relationships ◽

Asia Pacific ◽

Invasion History ◽

Cylas Formicarius ◽

Low Genetic Diversity ◽

History Of ◽

Potato Insect

Abstract Cylas formicarius F. and Euscepes batatae Waterhouse are the most damaging sweet potato insect pests globally. Both weevils are thought to have invaded the Pacific alongside the movement of sweet potato (Ipomoea batatas (L.) Lam. Convolvulaceae), with C. formicarius having originated in India and E. batatae in Central or South America. Here we compare the genetic relationships between populations of the pests, primarily in the Asia-Pacific, to understand better their contemporary population structure and their historical movement relative to that of sweet potato. Cylas formicarius has divergent mitochondrial lineages that indicate a more complex biogeographic and invasive history than is presently assumed for this insect, suggesting it was widespread across the Asia-Pacific before the arrival of sweet potato. Cylas formicarius must have originally fed on Ipomoea species other than I. batatas but the identity of these species is presently unknown. Cylas formicarius was formerly designated as three species or subspecies and the genetic data presented here suggests that these designations should be reinvestigated. Euscepes batatae has very low genetic diversity which is consistent with its historical association with sweet potato and a recent introduction to the Asia-Pacific from the Americas. The distribution of E. batatae may be narrower than that of C. formicarius in the Asia-Pacific because it has relied relatively more on human-assisted movement. Consequently, E. batatae may become more widespread in the future. Investigating the invasion history of both species will help to understand the probability and nature of future invasions.

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Sweet potato (Ipomoea batatas) cultivar susceptibility to the borer Cylas formicarius var. elegantulus

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v74i2.6549 ◽

1969 ◽

Vol 74 (2) ◽

pp. 167-179

Author(s):

Irma Cabrera ◽

Carlos Cruz ◽

Arístides M. Armstrong ◽

Nelia Acosta

Keyword(s):

Puerto Rico ◽

Sweet Potato ◽

Ipomoea Batatas ◽

Field Experiments ◽

Total Yield ◽

Susceptible Variety ◽

Internal Damage ◽

Cylas Formicarius ◽

Cultivar Susceptibility

Two field experiments were undertaken in Puerto Rico, one in Isabela and another in Mayagüez, to determine the susceptibility of several cultivars of Ipomoea batatas (L.) (Lam.) to Cylas formicarius var. elegantulus (Summers). Although the total yield of the cultivars was not affected by the initial injuries caused by the insect, the quality of the tuber was affected in both experiments. The degree of susceptibility in each experiment was determined from the internal damage and the number of larvae in the tubers. In Isabela, cultivars WRAS-3, WRAS-7, WRAS-31, WRAS-36, Mojave and Gem were highly susceptible to the weevil attacks, whereas varieties Regal and Sumor and the WRAS-7 line were moderately susceptible. In Mayagüez cultivars WRAS-36, Mojave, Miguela and Gem were highly susceptible to the attack of the insect. Cultivars WRAS-3, WRAS-7, Resisto, Sumor, WRAS-25, WRAS-31, WRAS-35, were moderately susceptible. Variety Regal and the WRAS-37 and WRAS-40 lines were the most resistant to the attack of Cylas formicarius.

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Acoustical Detection of the Sweetpotato Weevil (Coleoptera: Curculionidae) in Sweet Potato2

Journal of Entomological Science ◽

10.18474/0749-8004-28.4.453 ◽

1993 ◽

Vol 28 (4) ◽

pp. 453-461

Author(s):

James D. Hansen

Keyword(s):

Mathematical Models ◽

Sweet Potato ◽

Ipomoea Batatas ◽

Observation Data ◽

Substantial Variation ◽

Sweet Potatoes ◽

Sweetpotato Weevil ◽

Cylas Formicarius ◽

Cylas Formicarius Elegantulus ◽

Observation Period

Ultrasensitive acoustical equipment was used to detect larvae of the sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae), in the sweet potato, Ipomoea batatas (L.). Methods of expressing results were evaluated with per cent audible as the best indicator of larval presence. Sound from moderately infested sweet potatoes (8 to 20 weevils/sweet potato) varied considerably even though infestation rates above 60 weevils/sweet potato resulted in sound throughout most of the observation period. Infested sweet potatoes were detectable after two weeks of weevil development; maximum values were observed a month after infestation. However, the substantial variation of the observation data precluded descriptive mathematical models based on infestation rate or weevil development. Disease processes also caused signals that were indistinguishable from those made by sweetpotato larvae. Other factors that influence detectability are also discussed.

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The virulence improvement of Beauveria bassiana in infecting Cylas formicarius modulated by various chitin based compounds

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200909 ◽

2019 ◽

Vol 20 (9) ◽

Cited By ~ 1

Author(s):

Triono bagus Saputro ◽

YUSMANI PRAYOGO ◽

FARADIBA LAZUARDI ROHMAN ◽

NUR HIDAYATUL ALAMI

Keyword(s):

Sweet Potato ◽

Beauveria Bassiana ◽

Ipomoea Batatas ◽

Animal Feed ◽

Raw Materials ◽

Biological Control Agent ◽

Control Agent ◽

Carbohydrate Source ◽

Cylas Formicarius ◽

Different Characteristics

Abstract. Saputro TB, Prayogo Y, Rohman FL, Alami NH. 2019. The virulence improvement of Beauveria bassiana in infecting Cylas formicarius modulated by various chitin based compounds. Biodiversitas 20: 2486-2493. Sweet potato (Ipomoea batatas L.) is one of alternative carbohydrate source with an important role in food production, animal feed industries, and as raw materials for other derivatives. However, severe losses are constantly occurred in its production due to a notorious pest known as sweet potato weevil (Cylas formicarius). The chemical insecticides commonly used to treat the pest, but have not been efficient in eliminating C.formicarius. Beauveria bassiana is well known as a biological control agent, has been identified to effectively eliminate the pest. The aim of this research is to observe the optimum concentration of several chitin-based compounds in improving the virulence of B. bassiana. The research was conducted by the addition of chitin from various sources - insects, crustaceans and mollusk shells in a growth medium of B. Bassiana. Moreover, conidia produced by B.bassiana was exposed to C.formicarius to investigate the mortality rate of this insect. The results showed four different characteristics of colonies - velvety, wooly, pellicular, and farinaceous. The 1% chitin from Tellina sp, (P9), was found to be the best treatment which increased the growth of the colony diameter attaining 6.7cm in 20 days, increased the conidia viability that reaches 93.5%. In addition, the highest mortality percentage of C. formicarius was 91.67% in P9 at 6 days after infection. Overall, this research gave new potential sources of chitin that can be applied in improving the virulence of B. Bassiana in eliminating C. formicarius.

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