Preponderance and distribution of plant-parasitic nematodes in Nassarawa State,North Central Nigeria: Consequences for healthy tuber production and export

One of the most cosmopolitan pests responsible for considerable negative economic impacts on yam is the plant-parasitic nematodes. They are also capable of facilitating fungal, bacterial and viral infections of yams. In order to produce healthy yam seeds to meet local demand and tubers for export, there is a need to identify nematode-free areas in Nassarawa, one of the hubs of yam production in Nigeria. To this end, 30 major yam growing communities of the state were surveyed to identify nematode-free areas. Structured questionnaires were administered to three farmers in each of the 10 local government areas selected. Results showed that 97% of the study areas investigated was seriously infested with the three key genera of plant-parasitic nematodes namely Scutellonema, Pratylenchus and Meloidogyne. Incidence and severity of tuber deterioration in transit threatened acceptability of the tubers when it eventually reached England. Healthy yams would attract more income than damaged ones.     

Pathogenic and genetic variability among Colletotrichum gloeosporioides isolates from different yam hosts in the agroecological zones in Nigeria

Anthracnose, caused by Colletotrichum gloeosporioides Penz., is the most severe foliar disease of water yam (Dioscorea alata) worldwide. Population genetic analyses can yield useful insights into the evolutionary potential of C. gloeosporioides and thus lead to the development of appropriate disease management strategies. The genetic structure of C. gloeosporioides populations from yam and non‐yam hosts in three agroecological zones of Nigeria was investigated. Microsatellite‐primed polymerase chain reaction (MP‐PCR), virulence phenotyping using five putative D. alata differentials, cross‐inoculation tests, and the presence/absence of a Glomerella teleomorph in yam fields were used to infer the evolutionary potential of C. gloeosporioides on yam. We observed high genotypic diversity (GD = 0.99 to 1.00) for populations from all hosts and agroecological zones, with multiple pathogen genotypes in individual anthracnose lesions. Genetic differentiation was low among pathogen populations from different hosts (G_ST = 0.10, θ = 0.034), and agroecological zones (G_ST = 0.04, θ = 0.018), indicating limited host differentiation and significant gene flow. No evidence was found for the existence of C. gloeosporioides f. sp. alatae reported in previous studies. The fungus was recovered from several non‐yam host species commonly found in yam fields but non‐yam isolates caused only mild to moderate symptoms on yam. Eighteen C. gloeosporioides virulence phenotypes were identified among 217 isolates but there was a weak correlation (r = 0.02, P = 0.40) between virulence phenotype and MP‐PCR haplotype. Consistent with the above findings, we observed for the first time the Glomerella teleomorph on anthracnose‐infected yam plants in Nigeria, indicating that sexual recombination might play an important role in anthracnose epidemics on yam. The implications of these findings for C. gloeosporioides evolutionary potential and anthracnose resistance breeding are discussed.     

山药异淀粉酶基因克隆及其在淀粉代谢中的作用北大核心CSCD

为了明确异淀粉酶基因(ISA 3)在山药淀粉代谢中的作用,该研究以‘毕克齐’和‘大和长芋’山药为试验材料,测定了块茎中淀粉及组分含量和异淀粉酶活性等;采用RT-PCR技术克隆了ISA 3,并进行生物学分析及山药块茎不同膨大期和不同组织间ISA 3基因的表达等。结果表明:(1)山药‘大和长芋’的直链淀粉、支链淀粉和总淀粉含量均显著高于‘毕克齐’,且两品种的淀粉含量随生长发育的变化均呈先升高后降低的趋势,并均于种植后120 d时达到最高,但‘毕克齐’的异淀粉酶(ISA)活性在整个膨大期均高于‘大和长芋’。(2)成功克隆获得山药ISA 3开放阅读框长1584 bp,编码527个氨基酸;ISA3为亲水性蛋白。(3)不同品种块茎在膨大时期的ISA 3基因表达趋势不同,‘毕克齐’中呈先显著上调随后下调,而在‘大和长芋’中表达总体下调,且在山药的叶、茎和块茎中均有表达,存在明显的组织特异性。(4)ISA活性与山药淀粉及支链淀粉含量呈显著和极显著正相关关系,但ISA活性与ISA 3的表达量呈负相关关系。研究表明,异淀粉酶参与了山药块茎中淀粉的合成,且主要对支链淀粉的合成起关键作用,ISA 3基因的表达可能对异淀粉酶活性和淀粉的合成起负调控作用。     

Optimizing Controlled Environment Assessment of Levels of Resistance to Yam Anthracnose Disease Using Tissue Culture-derived Whole Plants

Studies were conducted to determine the timing and frequency of disease assessment required to effectively identify levels of resistance to yam anthracnose using tissue culture‐derived whole plant inoculation assay. The effects of inoculation methods (paint brush and spray), and disease scoring methods [individual leaf area (ILA) and whole plant area (WPA)] were also assessed. Spray inoculation resulted in rapid infection and higher variations among yam genotypes, leading to earlier discrimination of genotypes than with the paintbrush method. Both the ILA and WPA scoring methods showed variation among yam genotypes, and association between the two methods gave a high positive correlation (r > 0.90). However, the WPA was faster and had the advantage of detecting differences in reactions of yam genotypes to less aggressive pathogen isolates to which the ILA method showed no variation. A single disease evaluation at 7 days after inoculation was as good as the area under the disease progress curve (AUDPC) and the disease progress rate (R_d) derived from multiple evaluations. However, a significant time–genotype interaction, suggests a need for more than a single assessment for effective comparison of genotypes. AUDPC derived from two assessments (5 and 7 DAI) was better than AUDPC from three assessments (5, 7 and 9 DAI) in separating genotypes reactions to a less aggressive pathogen isolate. This study showed that the use of spray inoculation method, the WPA scoring method, and AUDPC derived from two assessments (5 and 7 DAI) provided best conditions for evaluating yam genotypes for levels of anthracnose resistance with the tissue culture‐derived whole plant assay.     

Strategies to combat the problem of yam anthracnose disease: Status and prospects

Yam (Dioscorea spp.) anthracnose, caused by Colletotrichum alatae, is the most devastating fungal disease of yam in West Africa, leading to 50%–90% of tuber yield losses in severe cases. In some instances, plants die without producing any tubers or each shoot may produce several small tubers before it dies if the disease strikes early. C. alatae affects all parts of the yam plant at all stages of development, including leaves, stems, tubers, and seeds of yams, and it is highly prevalent in the yam belt region and other yam-producing countries in the world. Traditional methods adopted by farmers to control the disease have not been very successful. Fungicides have also failed to provide long-lasting control. Although conventional breeding and genomics-assisted breeding have been used to develop some level of resistance to anthracnose in Dioscorea alata, the appearance of new and more virulent strains makes the development of improved varieties with broad-spectrum and durable resistance critical. These shortcomings, coupled with interspecific incompatibility, dioecy, polyploidy, poor flowering, and the long breeding cycle of the crop, have prompted researchers to explore biotechnological techniques to complement conventional breeding to speed up crop improvement. Modern biotechnological tools have the potential of producing fungus-resistant cultivars, thereby bypassing the natural bottlenecks of traditional breeding. This article reviews the existing biotechnological strategies and proposes several approaches that could be adopted to develop anthracnose-resistant yam varieties for improved food security in West Africa.     

Two Genetically Distinct Populations of Colletotrichum gloeosporioides Penz. Causing Anthracnose Disease of Yam (Dioscorea spp.)

Variation within Colletotrichum gloeosporioides, the causal agent of yam anthracnose disease, is still poorly defined and this hinders breeding for resistance. Two morphotypes of C. gloeosporioides, designated slow‐growing grey (SGG) and fast‐growing salmon (FGS), are associated with anthracnose disease of yam in Nigeria. The morphotypes are distinguishable based on colony and conidial morphology, growth rate, virulence, as well as vegetative compatibility, but molecular differentiation of SGG and FGS strains is needed to facilitate epidemiological studies. Denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)‐amplified small subunit (18S) rDNA fragments, and microsatellite‐primed PCR (MP‐PCR) genomic fingerprinting were employed to provide a basis for molecular differentiation of the morphotypes. DGGE analysis revealed patterns that clearly differentiated isolates of the aggressive defoliating SGG from the moderately virulent non‐defoliating FGS strains. Genetic analysis based on 52 MP‐PCR markers revealed highly significant differentiation between the SGG and FGS populations on yam (G_ST = 0.22; Nei's genetic identity = 0.85; θ = 0.28, P < 0.001), indicating that the SGG and FGS morphotypes represent genetically differentiated populations. The results of the molecular typing using DGGE and MP‐PCR analyses were consistent with the disease phenotype caused by the two morphotypes. Consequently, these molecular techniques might be used, at least partly, to replace time‐consuming virulence studies on yam.     

Vegetative Compatibility Among Isolates of Colletotrichum gloeosporioides from Yam (Dioscorea spp.) in Nigeria

Isolates of Colletotrichum gloeosporioides obtained from yam‐based cropping systems in Nigeria, previously characterized on the basis of morphology, virulence and rDNA internal transcribed spacer (ITS) sequence variation were further compared for vegetative compatibility (VC). Chlorate‐resistant nitrate non‐utilizing (nit) mutants were generated from the isolates and used in complementation (heterokaryon) tests. Tests of VC between complementary mutants from different isolates indicated the presence of several genotypes within a single field, suggesting limited clonal spread. In some cases, isolates obtained from the same lesion were observed to belong to different vegetative compatibility groups (VCGs). No compatibility was observed between isolates of the highly virulent slow‐growing grey (SGG), the moderately virulent fast‐growing salmon (FGS) and the avirulent/weakly virulent fast‐growing grey (FGG) strains. Forty‐one C. gloeosporioides isolates belonged to 28 VCGs, giving a genotype diversity estimate of 0.68. This diversity confirmed the high variability of the pathogen population as revealed by previous characterization studies, however, a correlation between VCGs and isolate groupings based on morphology and virulence was not found. The finding that an isolate from weed was compatible with yam isolates indicated that transfer of important traits, such as virulence, may take place between isolates from yam and non‐yam hosts. The VCG diversity revealed by this study suggests that in addition to asexual reproduction, sexual reproduction may play an important role in the epidemiology of anthracnose on yam.     

Assessment of sorghum genetic resources of Ethiopia for anthracnose (Colletotrichum sublineolum Henn.) resistance and agronomic traits

Sorghum anthracnose caused by Colletotrichum sublineolum Henn. is one of the key diseases limiting sorghum production and productivity. Development of anthracnose‐resistant sorghum genotypes possessing yield‐promoting agronomic traits is an important breeding goal in sorghum improvement programs. The objective of this study was to determine the responses of diverse sorghum genetic resources for anthracnose resistance and agronomic traits to identify desirable lines for breeding. A total of 366 sorghum collections and three standard checks were field evaluated during the 2016 and 2017 cropping seasons. Lines were artificially inoculated with a virulent pure isolate of the pathogen. Anthracnose disease severity was assessed to calculate the area under disease progress curve (AUDPC). Agronomic traits such as panicle length (PL), panicle width (PW), head weight (HW) and thousand grain weight (TGW) were measured. Lines showed highly significant differences (p < .001) for anthracnose severity, AUDPC and agronomic traits. Among the collections 32 lines developed levels of disease severity between 15% and 30% in both seasons. The following sorghum landraces were selected: 71708, 210903, 74222, 73955, 74685, 74670, 74656, 74183, 234112, 69412, 226057, 214852, 71420, 71484, 200126, 71557, 75120, 71547, 220014, 228179, 16212, 16173, 16133, 69088, 238388, 16168 and 71570. These landraces had a relatively low anthracnose severity possessing farmer‐preferred agronomic traits. The selected genotypes are useful genetic resources to develop anthracnose‐resistant sorghum cultivars.     

CDPK20基因表达及其对山药块茎膨大调控作用研究

为探讨钙依赖性蛋白激酶(CDPK)在山药块茎淀粉及内源激素合成中的作用,该研究以'毕克齐'和'大和长芋'山药为试验材料,测定了块茎的淀粉、糖、内源激素含量等指标并进行相关性分析;采用RT-PCR技术克隆了钙依赖性蛋白激酶基因(CDPK20),并进行生物信息学分析,构建CDPK:GFP融合载体,对CDPK蛋白进行亚细胞定...     

Effect of mound size and fertilizer on white Guinea yam (Dioscorea rotundata) in Southern Nigeria

Summary Field trials were conducted in the forest zone of southern Nigeria on three soil series, gravelly loamy sand Ibadan soil (Oxic paleustalf), gravelly sandy loam Egbeda soil (Oxic paleustalf) and sandy loam Alagba soil (Oxic paleustalf). The trials were carried out to study the effects of planting on flatversus various mound sizes and NPK fertilizer on performance of white Guinea yam (Dioscorea rotundata) cultivar Laoko.Mound size appeared to have a more pronounced effect on tuber yield than fertilizer even on land which was in the second and third year of cropping after bush fallow. The average tuber yield for the three locations without fertilizers was 7.83 tons/ha on the flat compared with 9.44 tons/ha on large mound (about 30 cm height). With fertilizer application, tuber yields were 7.43 tons/ha on the flat and 11.30 tons/ha on large mound respectively. Total yield reduction on flat may in part be related to physical soil impedence. Planting on large mounds also resulted in longer tubers and shorter harvesting time.     

Evaluation of isolates of Trichoderma,Pseudomonas and Bacillus species as treatment for the control of post-harvest fungal rot disease of yam (Dioscorea spp.)

The efficacy of four biological control agents (BCAs): Trichoderma asperellum strain NGT158, T. longibrachiatum strain NGT167, Bacillus subtilis and Pseudomonas fluorescens for the management of post-harvest tuber rot among four yam species, Dioscorea rotundata, D. cayenensis, D. alata, and D. dumetorum was evaluated. Rotted yam tubers were collected across three agroecological zones in Nigeria to isolate six infecting fungal pathogens: Aspergillus niger, Lasiodiplodia theobromae, Rhizoctonia solani, Penicillium oxalicum, Fusarium oxysporum and Sclerotium rolfsii. The BCAs were isolated by serial dilution and rot inhibition of treated tubers was evaluated using destructive sampling method in vivo after six months of storage. Bacillus subtilis was generally most effective, especially when applied 24 h before the inoculation of test pathogens across the four yam species, with percent inhibition that ranged between 47.8 and 81.2%. However, the four BCAs showed good potential in the control of the fungal pathogens causing post-harvest yam rot.     

Evaluation of Clove Essential Oil as a Mycobiocide Against Rhizopus stolonifer and Fusarium solani,Tuber Rot Causing Fungi in Yam (Dioscorea rotundata Poir.)

To exploit natural products for plant disease control, the essential oil of Syzygium aromaticum (L.) Merr. & Perr. (clove) was investigated for its antifungal activity against Rhizopus stolonifer and Fusarium solani, the postharvested yam tuber rot pathogens. The essential oil was obtained by hydrodistillation using a Clevenger‐type apparatus. The chemical composition of the oil was determined by gas chromatography and gas chromatography coupled with mass spectrometry. Antifungal activities of the oil were tested in vitro against mycelia growth and spores germination. In situ tests were conducted on healthy yam tubers, and necrosis symptoms were assessed. Results showed that eugenol (79.4%), eugenylacetate (9.2%) and isocaryophyllene (7.0%) were the major components. The oil exerted antifungal activities with total inhibition (TI) of the mycelia growth of R. stolonifer and F. solani was recorded at 200 and 300 ppm, respectively, while TI of spores germination was recorded at 31.25 and 250 ppm, respectively. For the standard fungicide (Ridomil^®), TI value of mycelia growth was 1600 ppm for the both pathogens, while TI of spores germination were 200 ppm and 1600 ppm, respectively, for Rhizopus and Fusarium. In situ tests showed complete inhibition of yam tuber rot when the essential oil was applied at 2000 ppm for preventive tests. This oil also reduced significantly (P ≤ 0.05) necrosis development on yam tuber for curative test at the same concentration. Total inhibition of the necrosis by Ridomil (3000 ppm) was observed only for Rhizopus on preventive test. There were positive correlations between the oil concentration and the reduction of necrosis cause by R. stolonifer and F. solani. These findings showed that clove essential oil may serve as environmental friendly bio‐fungicide for the management of postharvest yam tuber rot.     

Rapid assessment of resistance of tissue-cultured water yam (Dioscorea alata) and white guinea yam (Dioscorea rotundata) to anthracnose (Colletotrichum gloeosporioides Penz.)

Yam anthracnose is caused by the pathogen Colletotrichum gloeosporioides Penz. and has been identified as the most important biotic constraint to yam production worldwide. Rapid assessment of the disease is vital to its effective diagnosis and management. In this study, tissue-cultured yam plantlets of five lines of Dioscorea alata and nine of D. rotundata were rapidly assessed for their reactions to two isolates of yam anthracnose. The plantlets, obtained from meristem of the nodal cuttings, were grown for 8?weeks on Murashige and Skoog (MS) basal medium, acclimatised for 3?weeks, hardened for an additional 3?weeks, arranged in screen house in completely randomised design and sprayed with spore inocula prepared from 7?day-old culture of the two strains of Colletotrichum gloeosporioidies Penz. The relative resistance of the different Dioscorea spp. was evaluated using three disease indices – severity at seventh day after inoculation, SD7; area under disease progress curve, AUDPC; and disease severity rate, Rd. A modified rank-sum classification method put TDa 1425 and TDr 2040, with rank sum of 2.0 each, as resistant. TDr 2121, TDr 2287 and TDr 2048 were susceptible with rank sum of 27.50, 25.50 and 24.50, respectively. Dioscorea alata TDa 1425 and Dioscorea rotundata TDr 2040 were recommended in areas endemic with yam anthracnose, and also as parent lines while breeding for resistance to anthracnose.     

Phases of dormancy in Yam tubers (Dioscorea rotundata)

BACKGROUND AND AIMS: The control of dormancy in yam (Disocorea spp.) tubers is poorly understood and attempts to shorten the long dormant period (i.e. cause tubers to sprout or germinate much earlier) have been unsuccessful. The aim of this study was to identify and define the phases of dormancy in Dioscorea rotundata tubers, and to produce a framework within which dormancy can be more effectively studied. METHODS: Plants of 'TDr 131' derived from tissue culture were grown in a glasshouse simulating temperature and photoperiod at Ibadan (7 degrees N), Nigeria to produce tubers. Tubers were sampled on four occasions: 30 d before shoot senescence (149 days after planting, DAP), at shoot senescence (179 DAP), and twice during storage at a constant 25 degrees C (269 and 326 DAP). The development of the apical shoot bud was described from tissue sections. In addition, the responsiveness of shoot apical bud development to plant growth regulators (gibberellic acid, 2-chloroethanol and thiourea) applied to excised tuber sections was also examined 6 and 12 d after treatment. KEY RESULTS AND CONCLUSIONS: Three phases of tuber dormancy are proposed: Phase I, from tuber initiation to the appearance of the tuber germinating meristem; Phase II, from the tuber germinating meristem to initiation of foliar primordium; and Phase III, from foliar primordium to appearance of the shoot bud on the surface of the tuber. Phase I is the longest phase (approx. 220 d in 'TDr 131'), is not affected by PGRs and is proposed to be an endo-dormant phase. Phases II and III are shorter (<70 d in total), are influenced by PGRs and environmental conditions, and are therefore endo-/eco-dormant phases. To manipulate dormancy to allow off-season planting and more than one generation per year requires that the duration of Phase I is shortened.     

Mycoflora of tuber surface of white yam (Dioscorea rotundata poir) and postharvest control of pathogens with Bacillus subtilis

Bacillus subtilis (Enrenberg) Cohn was investigated for its antagonistic properties against surface mycoflora of yam (Dioscorea rotundata Poir) tubers in storage. Yam tubers inoculated with a spore suspension of B. subtilis in potato dextrose broth using a knapsack sprayer showed a drastic reduction in the range and number of mycoflora, including pathogens of the tuber surface in contrast to the control tubers, during the five-month storage period in a traditional yam barn. However, B. subtilis maintained a high frequency of occurrence during the same period. Botryodiploidia theobromae Pat, Fusarium moniliforme Wollen and Reink., Penicillium sclerotigenum Yamamoto, and Rhizoctonia sp. were displaced completely on the treated tubers. The antagonism of B. subtilis was so effective that the normal tuber surface mycoflora was greatly reduced throughout the storage period of five months by a simple initial application of the antagonist.This revised version was published online in October 2005 with corrections to the Cover Date.     

Screening of cassava (Manihot esculenta Crantz) accessions against Phytophthora palmivora induced tuber rot of cassava

Cassava (Manihot esculenta Crantz), is an important tropical tuber crop with global importance and plays a significant role in the food, nutritional and livelihood security of around 500 million people. In India, the low productivity of cassava attributes to the soil borne disease, particularly tuber rot caused by Phytophthora palmivora (Butl.) which is destructive and the attack is spreading in alarming rate in all the cassava growing regions causing heavy yield loss of more than 50%. Introduction of disease resistant varieties may alleviate the problem to a certain extent. This paper describes the screening procedures and findings on the disease resistant variety of cassava accession against tuber rot. Variety Sree Padmanabha imparted high resistance against tuber rot, while Sree Sahya was moderately resistant and all other accessions studied were found to be susceptible in in vitro and in field trials. In screening studies, a reproducible positive correlation was obtained between attached tubers in live plant with detached tubers which showed that detached tuber part can be used for the prediction of resistance in attached live plants of cassava for cultivar resistance. The procedure described here could be used as a simple, rapid and efficient method for screening of cassava accessions against tuber rot of cassava.     

Pathogenicity of Pratylenchus coffeae,Scutellonema bradys,Meloidogyne incognita,and Rotylenchus reniformis on Dioscorea rotundata

Low populations (200 specimens per plant) of Pratylenchus cofl''eae, Scutellonema bradys, Meloidogyne incognita, and Rotylenchulus reniformis stimulated the development of tops, roots, and tubers of Dioscorea rotundata "Guinea" yam. We demonstrated experimentally that P. coffeae was responsible for the deterioration in quality of the yam tuber in Puerto Rico, a condition known as a dry rot of yam. Initial populations of 600 P. coffeae, S. bradys, or M. incognita, and populations of 1,000 P. coffeae or S. bradys per plant were high enough to induce dry rot of the yam tubers. P. coffeae and S. bradys were pathogenic to yam cultivar Guinea, but M. incognita and R. reniformis did not cause necrosis or cracking of the tuber cortex in our experiments.     

Field Studies on Cross-protection against Japanese yam mosaic virus in Chinese yam (Dioscorea opposita) with an Attenuated Strain of the Virus

An attenuated strain of Japanese yam mosaic virus (JYMV), designated T‐3, was evaluated for its cross‐protection efficacy against virulent (native) strains of JYMV in Chinese yam (Dioscorea opposita) grown in farmers’ fields in Japan. Native strains of JYMV were detected by a polymerase chain reaction‐based assay in all the Chinese yam plants grown from virus‐free tubers in the first growing season in the fields. In contrast, the virus was detected in only one of fifty plants grown from tubers preinoculated with T‐3 during the experiments for 6 years, suggesting that T‐3 consistently cross‐protected against native JYMV in Chinese yam in the field. Chinese yam plants preinoculated with T‐3 produced significantly greater yield of tubers per plant compared with non‐inoculated plants.     

Biological control of anthracnose (Colletotrichum gloeosporioides) in yam by Streptomyces sp.MJM5763

Aim: To find a suitable biocontrol agent for yam anthracnose caused by Colletotrichum gloeosporioides. Methods and Results: An actinobacterial strain, MJM5763, showing strong antifungal activity, multiple biocontrol and plant growth‐promoting traits was isolated from a yam cultivation field in Yeoju, South Korea. Based on morphological and physiological characteristics and analysis of the 16S rDNA sequence, strain MJM5763 was identified as a novel strain of Streptomyces and was designated as Streptomyces sp. MJM5763. Treatment with MJM5763 and the crude culture filtrate extract (CCFE) was effective in suppressing anthracnose in detached yam leaves in vitro and reduced incidence and severity of anthracnose in yam plants under greenhouse conditions. The CCFE treatment was the most effective of all the treatments and reduced the anthracnose severity by 85–88% and the incidence by 79–81%, 90 days after inoculation with the pathogen. CCFE treatment was also effective under field conditions and showed a reduction of 86 and 75% of anthracnose severity and incidence, respectively. Conclusion: Streptomyces sp. strain MJM5763 was effective in biocontrolling anthracnose in yam caused by C. gloeosporioides. Significance and Impact of the Study: Streptomyces sp. MJM5763 is a potential alternative to chemical fungicides for reducing yield losses to anthracnose in yam.     

Tuber production,dormancy and resistance against Phthorimaea operculella (Zeller) in wild potato species

The diversification of resistant potato varieties at a landscape level could slow adaptation by Phthorimaea operculella to potato resistance and promote sustainable crop protection. In this study, we assessed wild potato species as novel sources of foliage and tuber resistance against P. operculella. Tuber resistance was quantified for 136 and foliage resistance for 54 potato accessions representing 14 and nine potato species, respectively. Several accessions were highly resistant to moth damage in tubers and/or foliage. In particular, Solanum chiquidenum and Solanum sandemanii were highly resistant to damage in tubers. Several accessions of Solanum multiinterruptum and a small number of accessions of Solanum bukasovii, Solanum berthaultii, Solanum sparsipilum and Solanum wittmackii also had highly resistant tubers. Larval survival on foliage of S. bukasovii and S. chiquidenum was generally low. New resistance sources are listed, and insect performance on the plants is described with possible resistance mechanisms. The study also examined potential trade‐offs associated with resistance. Tuber resistance was negatively correlated with the number and weight of tubers produced per plant, but positively correlated with the length of dormancy across accessions, indicating that, although long dormancy is not a prerequisite for resistance, species and accessions with extended dormancy will have more resistant tubers. Tuber and foliage resistance were generally positively correlated across all accessions; however, among accessions from within a potato species, there were negative (S. berthaultii), positive (S. chiquidenum) and non‐significant (S. bukasovii) relations. These results indicate that, besides identifying novel resistance sources, an improved understanding of the mechanisms and inherent trade‐offs associated with tuber and foliage resistance will improve the efficiency of potato breeding programmes aimed at enhancing resistance against P. operculella.