Resistant Varieties Research Articles

Evaluation of bread wheat germplasm for adult plant resistance to stem rust using artificial inoculation

Wheat stem rust, caused by Puccinia graminis f.sp. tritici, is a major biotic threat to wheat (Triticum aestivum L.) in many wheat-producing countries worldwide, including Ethiopia. The pathogen is capable of continuously evolving new fungal races with high reproductive potential. It can be easily dispersed by wind over large geographic areas, allowing it to attack resistant varieties. Under optimal environmental conditions, it can cause epidemics leading to severe yield losses (up to 100%). A total of 91 germplasms, comprising 81 advanced bread wheat lines and 10 varieties, including the susceptible check Morocco, were planted using an augmented design. The experiment was conducted with artificial inoculation on spreaders to evaluate their slow rusting response against four virulent stem rust races viz. TTKTF, TKKTF, TTKTT, and TTTTF under field conditions at the Kulumsa Agricultural Research Center during the 2022-2023 offseason. Slow rusting resistance at the adult-plant stage was assessed by measuring the final rust severity (FRS) and the average coefficient of infection (ACI). Accordingly, 50 (61.7%) of the advanced lines and 6 (60%) of the released varieties namely Boru, Abay, Shaki, Kakaba, Deka, and Dursa exhibited low levels of FRS and ACI. In contrast, 31 (48.3%) of the advanced lines and 4 (40%) of the varieties showed high FRS and ACI values. The germplasms with low FRS and ACI values were considered to exhibit good slow rusting resistance and could be recommended for release into production and/or used in breeding programs aimed at achieving durable stem rust resistance in Ethiopia.

Progresses in lowland pulse insect pest management in Ethiopia

Grain legumes are one of the important cash crops for Ethiopian smallholder farmers and a significant agricultural commodity contributing to export earnings. Lowland pulses are comparatively inexpensive sources of protein in Ethiopia. However, these economically important crops are affected by various pests. Among the most damaging in storage are bruchids (Acanthoscelides obtectus, Zabrotes subfasciatus, and Callosobruchus spp.), while in production fields, the primary pests include the bean stem maggot (Ophiomyia spp.), African bollworm (Helicoverpa armigera), and aphids (Aphis craccivora Koch). Estimated yield losses due to bean stem maggot and African bollworm range from 11-100% and 12-16%, respectively. Various pest control strategies have been employed, including the use of resistant varieties, biological control, botanical treatments, and chemical control. This review summarizes relevant scientific studies on these economically important crops, the associated insect pests, the aggravating factors in Ethiopia, and available management options.

Monitoring of Virulence of Gall Midge (Orseolia oryzae Wood-mason) Population on Rice

A study was conducted for two years during 2022 and 2023 at Regional Agricultural Research Station, Warangal, Telangana, India to know the virulence of gall midge on rice varieties with known gall midge resistant genes at Warangal. During both the years i.e., 2022 and 2023, the virulence of gall midge was low in Aganni followed by Akshayadhan, W1263 and Purple. The gall midge virulence was very low and similar in Aganni and Akshayadhan which reveals the efficacy of gall midge resistance genes i.e., Gm4 and Gm8 against gall midge biotype 4M at Warangal. Since Purple variety does not have any gall midge resistant genes, gall midge virulence was highest on Purple variety. The study revealed that, gall midge genes viz., Gm4 and Gm8 are holding good for resistance against gall midge biotype 4M in both the years of study. However, a close monitoring of the virulence pattern in endemic areas is important for deployment of effective genes in developing resistant varieties.

Virulence variation and pathotypes of Zymoseptoria tritici isolates causing wheat leaf blotch in Oromia, Ethiopia

Leaf blotch, caused by Zymoseptoria tritici, is a fungal disease that poses a severe threat to wheat production worldwide. Knowledge of virulence variability is crucial in choosing effective control measures. However, there have only been a few studies of the pathogenic variability and pathotypes within Ethiopian isolates. Hence, the objective of this study was to assess the virulence spectrum and variability of Z. tritici isolates. Forty-three isolates were tested for their virulence and pathotype against 7 wheat differential lines that have different resistance genes. A pathogenicity assay detected 41 differential line-specific virulent isolates among 301 interactions between a host and pathogen based on the percentage coverage of the leaf area by pycnidia. Some isolates were virulent against 50 %–60 % of the resistant genes, but most of them were virulent against some differential lines. Isolates such as EtA-11, EtSh-1, EtSh-2, EtSh-4, and EtA-19 expressed broad-spectrum virulence, highlighting that such isolates are useful for germplasm screening. The isolates were classified into 25 pathotypes, defined by their differential virulence responses. They were also assigned to two clusters according to their mean pycnidia percent. Pathotypes and principal component analysis detected 58.1 % and 62.2 % pathogenic diversity in Ethiopian isolates, respectively. The current findings provide information that breeders can use to identify and select more resistant varieties for farmers.

History of breeding programmes for fungus resistant grape varieties in Europe, France and the Occitanie region

History of breeding programmes for fungus resistant grape varieties in Europe, France and the Occitanie region

Enhancing crop resistance to root nematodes through advanced breeding techniques

This study aimed to evaluate the effectiveness of using nematode-resistant maize and cassava in Nigeria to improve farmers' sustainability and reduce pest pressures. Nematodes significantly impact global crop yield and availability, necessitating the development of resistant cultivars to reduce yield losses and reliance on chemical control measures. Field experiments were conducted in Agbor-Nta, Nigeria, using Resistant Variety A and Resistant Variety D developed from CRISPRCas9 and Marker Assisted Selection. The study found that Resistant Variety A reduced nematode count by 80%, increased yields, and higher net profits. Resistant Variety D also showed reasonable nematode control and economic returns, significantly reducing the nematode population to 12 per gram, achieving a 76% reduction. The adoption rate of CRISPR-Cas9 developed Resistant Variety A reached 50% by 2024. The study underscored the importance of advanced breeding technologies in producing nematode-resistant crops for farming sustainability and economies. The application of germplasm from CRISPR-Cas9 and MAS techniques successfully improved genetic improvement, reduced pest pressures, and enhanced yields. These findings align with efforts to improve agricultural sustainability by promoting reliable crop types to maintain food supply and economic stability in agricultural-dependent areas.

The growth‐promoting effects of Bacillus amyloliquefaciens W82T‐44 on soybean and its biocontrol potential against soybean Phytophthora root rot

AbstractThe most devastating soilborne disease of soybean is Phytophthora root rot (PRR) caused by Phytophthora sojae. Biological control has emerged as an effective method of reducing soilborne diseases. The present study isolated the bacterial strain W82T‐44 from the rhizosphere soil of a resistant soybean variety Williams 82. This strain was identified as Bacillus amyloliquefaciens and exhibited a 92.4% inhibition of mycelial growth of P. sojae. W82T‐44 produced cellulase, siderophore and protease and significantly promoted soybean growth. W82T‐44 treatment, compared to the negative control, was found to significantly (p < 0.05) increase soybean plant height (22.34 vs. 18.47 cm), fresh weight of the whole plant (2.57 vs. 2.05 g), dry weight (0.43 vs. 0.32 g), total root length (266.80 vs. 182.53 cm), root area (27.10 vs. 17.84 cm2) and root volume (1.88 vs. 1.16 cm3). The fermentation filtrate of W82T‐44 had significant inhibitory effects on mycelial growth, oospore formation and cyst germination in P. sojae and additionally promoted zoospore encystment. W82T‐44 possessed genes involved in lipopeptide synthesis, including bacilysin, surfactin, fengycin and bacillomycin. Moreover, it significantly upregulated pathogenesis‐related genes (β‐1,3‐glucanase, nonexpressor of pathogenesis‐related gene 1, chitinase) and genes encoding defence enzymes (polyphenol oxidase, phenylalanine ammonia‐lyase, peroxidase) in soybean roots (p < 0.05). The PRR disease index of soybean treated with the W82T‐44 strain was significantly lower (11.67) than the negative control (40.00; p < 0.05). The present study indicates the potential of B. amyloliquefaciens W82T‐44 as a biological control agent against PRR from various perspectives.

Mechanism of Rice Resistance to Bacterial Leaf Blight via Phytohormones.

Rice is one of the most important food crops in the world, and its yield restricts global food security. However, various diseases and pests of rice pose a great threat to food security. Among them, bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious bacterial diseases affecting rice globally, creating an increasingly urgent need for research in breeding resistant varieties. Phytohormones are widely involved in disease resistance, such as auxin, abscisic acid (ABA), ethylene (ET), jasmonic acid (JA), and salicylic acid (SA). In recent years, breakthroughs have been made in the analysis of their regulatory mechanism in BLB resistance in rice. In this review, a series of achievements of phytohormones in rice BLB resistance in recent years were summarized, the genes involved and their signaling pathways were reviewed, and a breeding strategy combining the phytohormones regulation network with modern breeding techniques was proposed, with the intention of applying this strategy to molecular breeding work and playing a reference role for how to further improve rice resistance.

Management of Huanglongbing of Citrus: Lessons from São Paulo and Florida.

São Paulo, Brazil, and Florida, USA, were the two major orange production areas in the world until Huanglongbing (HLB) was discovered in São Paulo in 2004 and Florida in 2005. In the absence of resistant citrus varieties, HLB is the most destructive citrus disease known because of the lack of effective tools to reduce spread of the vector, Diaphorina citri (Asian citrus psyllid), and transmission of the associated pathogen, Candidatus Liberibacter asiaticus. In both countries, a three-pronged management approach was recommended and begun: planting only disease-free nursery trees, effective psyllid control, and removal of all symptomatic trees. In Brazil, these management procedures were continued and improved and resulted in relatively little overall loss of production. In contrast, in Florida the citrus industry has been devastated with annual production reduced by approximately 80%. This review compares and contrasts various cultural and pest management strategies that have been used to reduce infection by the pathogen and increase tolerance of HLB in the main orange-growing regions in the world.

Exploring the Frontier of Wheat Rust Resistance: Latest Approaches, Mechanisms, and Novel Insights.

Wheat rusts, including leaf, stripe, and stem rust, have been a threat to global food security due to their devastating impact on wheat yields. In recent years, significant strides have been made in understanding wheat rusts, focusing on disease spread mechanisms, the discovery of new host resistance genes, and the molecular basis of rust pathogenesis. This review summarizes the latest approaches and studies in wheat rust research that provide a comprehensive understanding of disease mechanisms and new insights into control strategies. Recent advances in genetic resistance using modern genomics techniques, as well as molecular mechanisms of rust pathogenesis and host resistance, are discussed. In addition, innovative management strategies, including the use of fungicides and biological control agents, are reviewed, highlighting their role in combating wheat rust. This review also emphasizes the impact of climate change on rust epidemiology and underscores the importance of developing resistant wheat varieties along with adaptive management practices. Finally, gaps in knowledge are identified and suggestions for future research are made. This review aims to inform researchers, agronomists, and policy makers, and to contribute to the development of more effective and sustainable wheat rust control strategies.

MiRNAs profiles among three poplar varieties provide insights into different molecular responses in resistance to newly emerging bacterial pathogen.

Canker caused by Lonsdalea populi has seriously reduced the economic and ecological benefits of poplar. MicroRNAs play vital roles in the response of plants to biotic stress. However, there is little research about the regulatory mechanism of miRNAs among different tree varieties upon pathogen infection. To dissect miRNAs involved in L. populi resistance, three poplar varieties, 2025 (susceptible), 107 (moderately resistant) and Populus. tomentosa cv 'henan' (resistant) were selected to elucidate the expression profiles of miRNAs using small RNA-seq. A total of 227 miRNAs were identified from all varieties. Intriguingly, miR160, miR169, miR171 and miR482b-5p were only identified in the resistant variety P. tomentosa upon pathogen infection, and these miRNAs might be important candidates for future investigation to improve the tolerance of poplar to L. populi. Among all identified miRNAs, 174 were differentially expressed in all varieties. Functional annotation analysis indicated that an array of miRNAs, including miR482, miR472, miR169, miR481, and miR172, should be involved in disease resistance and phytohormone signal transduction. Furthermore, correlation analysis of small RNA-seq and RNA-seq identified a handful of L. populi-responsive miRNAs and target genes, which exhibited that miR159 and miR172 played key roles in resistant variety P. tomentosa by targeting MYB and ERF, while miR6462c-5p and miR828 were related to the susceptibility of 2025 by targeting MYB. The comprehensive integration analysis in this research provides new insights into the regulatory pathways involved in the defence response of poplar to L. populi and offers crucial candidate miRNAs-target genes modules for poplar resistance improvement.

Modeling the transmission dynamics of banana bunch top disease in banana plants

Banana Bunch Top Disease (BBTD) is a severe viral infection that poses a significant threat to banana production in tropical regions. Caused by the Banana Bunchy Top Virus (BBTV) and transmitted primarily by the banana aphid (Pentalonia nigronervosa), BBTD results in stunted growth and poor fruit production, leading to substantial economic losses. This paper presents a mathematical model to analyze the transmission dynamics of BBTD in banana plants and evaluate various control strategies using the Next Generation Matrix approach to compute the basic reproduction number R0. The study reveals that effective control of aphid populations, timely removal of infected plants, and the use of virus-free planting material significantly reduce the spread of BBTV and improve plant health. Increasing the removal rate γ and managing the transmission rate β are crucial strategies for controlling the disease, while elevated aphid infection rates λ and progression rates σ exacerbate its spread. Numerical simulations highlight the effectiveness of targeted interventions, including the application of pesticides and the introduction of resistant banana varieties. The study recommends that, in addition to current control measures, more focus should be placed on comprehensive monitoring programs, early detection of symptoms, and community education on BBTD management strategies. Enhanced efforts in these areas are crucial to reducing the incidence of BBTD and improving the resilience of banana crops.

The Molecular Maze of Potyviral and Host Protein Interactions.

The negative effects of potyvirus diseases on the agricultural industry are extensive and global. Understanding how protein-protein interactions contribute to potyviral infections is imperative to developing resistant varieties that help counter the threat potyviruses pose. While many protein-protein interactions have been reported, only a fraction are essential for potyviral infection. Accumulating evidence demonstrates that potyviral infection processes are interconnected. For instance, the interaction between the eukaryotic initiation factor 4E (eIF4E) and viral protein genome-linked (VPg) is crucial for both viral translation and protecting viral RNA (vRNA). Additionally, recent evidence for open reading frames on the reverse-sense vRNA and for nonequimolar expression of viral proteins has challenged the previous polyprotein expression model. These discoveries will surely reveal more about the potyviral protein interactome. In this review, we present a synthesis of the potyviral infection cycle and discuss influential past discoveries and recent work on protein-protein interactions in various infection processes.

Foliar Resistance to a Natural Population of Plasmopara viticola in Some Grapevine Varieties Grown in Türkiye

ABSTRACTIt is critical to use a population of the pathogen that contains different strains to determine the resistance of grapevine varieties to the downy mildew pathogen Plasmopara viticola in a specific region. This study tested six local grape varieties (Çavuş, Kalecik Karası, Müşküle, Papaz Karası, Sultana and Yapıncak), eight Turkish registered varieties (Barış, Bozbey, Güzgülü, Özer Karası, Reçel Üzümü, Tekirdağ Çekirdeksizi, Trakya İlkeren and Yalova İncisi) and seven varieties of foreign origin (Cabernet Sauvignon, Cardinal, Chardonnay, Cinsault, Isabella, Semillon and Gamay) using detached leaf and leaf disc assays with pathogen populations collected from vineyards. There was a significant correlation for disease severity between the two assay methods. No sporulation was observed on the varieties Çavuş and Isabella in both assay methods. The variety Yapıncak had very low disease severity (2.00%) in the leaf disc assay, and the pathogen did not sporulate on this variety in the detached leaf assay. Cluster analysis was performed to determine the resistance level of the varieties against the pathogen, as different disease severities were observed in some varieties depending on the test method used, and the 21 varieties were classified into four clusters. Barış, Bozbey, Cardinal, Çavuş, Isabella, Semillon and Yapıncak in Cluster I exhibited the lowest disease severity mean (2.88%), while those in Cluster 3, including Cabernet Sauvignon, Güzgülü, Papaz Karası and Yalova Incisi, had the highest disease severity mean (56.75%). These varieties in Clusters 1 and 3 were considered highly resistant and highly susceptible, respectively. Leaf hair density, as reported in official variety descriptions, did not associate with reduced disease severity in the two assays. This study assessed the response of grapevine varieties to the P. viticola population in the region for the first time. The highly resistant and resistant varieties identified will provide new material for breeders and contribute to the improvement of organic viticulture in the area.

Identification and confirmation of powdery mildew (Erysiphe polygoni) resistance in pea germplasm

Erysiphe polygoni DC, the causative agent of powdery mildew, poses a significant threat to pea crop, resulting in substantial yield and economic losses. To address this menace, an exploration of intrinsic resistance within pea germplasm becomes imperative for effective disease management. In our study, phenotyping of 1095 pea accessions, sourced from both indigenous and exotic origins, under natural epiphytotic conditions during Rabi 2021-22, revealed a prevailing susceptibility, with over 60 per cent disease severity in majority of accessions. Remarkably, only 22 accessions, including IC208327, IC220109, IC220378, IC258401, IC262762, IC262849, IC267140, IC267174, IC267727, IC274039, IC274040, IC310074, IC311066, IC345548, IC424898, IC552779, IC613133, IC629544, IC629687, NC57793, IC220193 and EC598669, exhibited resistance with a disease score of <1. Subsequent, pot screening of these 22 resistant accessions under artificial epiphytotic conditions during Rabi 2022-23 confirmed their resistance showing disease severity ranging from 5.83 - 17.50 per cent. Recognizing the pivotal role of resistant varieties in disease management, these identified accessions hold immense potential as resistant donors in crop improvement programs.. KEYWORDS :Germplasm, pea, powdery mildew, resistance

A Putative Effector Pst-18220, from Puccinia striiformis f. sp. tritici, Participates in Rust Pathogenicity and Plant Defense Suppression.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), stands out as one of the most devastating epidemics impacting wheat production worldwide. Resistant wheat varieties had swiftly been overcome due to the emergence of new virulent Pst strains. Effectors secreted by Pst interfere with plant immunity, and verification of their biological function is extremely important for controlling wheat stripe rust. In this study, we identified an effector, Pst-18220, from Puccinia striiformis f. sp. tritici (Pst), which was induced during the early infection stage of Pst. Silencing the expression of Pst-18220 through virus-mediated host-induced gene silencing (HIGS) resulted in a decreased number of rust pustules. In Nicotiana benthamiana, it significantly suppressed cell death induced by Pseudomonas syringae pv. tomato (Pto) DC3000. In Arabidopsis, plants with stable overexpression of Pst-18220 showed increased susceptibility to Pto DC3000, accompanied by a decrease in the expression level of pattern-triggered immunity (PTI)/effector-triggered immunity (ETI)-related genes, namely, AtPCRK1, AtPCRK2, and AtBIK1. These results emphasize the significant role of the Pst candidate effector, Pst-18220, in rust pathogenicity and the suppression of plant defense mechanisms. This broadens our understanding of effectors without any known motif.

Deciphering the role of rhizosphere microbiota in modulating disease resistance in cabbage varieties

BackgroundCabbage Fusarium wilt (CFW) is a devastating disease caused by the soil-borne fungus Fusarium oxysporum f. sp. conglutinans (Foc). One of the optimal measures for managing CFW is the employment of tolerant/resistant cabbage varieties. However, the interplay between plant genotypes and the pathogen Foc in shaping the rhizosphere microbial community, and the consequent influence of these microbial assemblages on biological resistance, remains inadequately understood.ResultsBased on amplicon metabarcoding data, we observed distinct differences in the fungal alpha diversity index (Shannon index) and beta diversity index (unweighted Bray–Curtis dissimilarity) within the rhizosphere of the YR (resistant to Foc) and ZG (susceptible to Foc) cabbage varieties, irrespective of Foc inoculation. Notably, the Shannon diversity shifts in the resistant YR variety were more pronounced following Foc inoculation. Disease-resistant plant variety demonstrate a higher propensity for harboring beneficial microorganisms, such as Pseudomonas, and exhibit superior capabilities in evading harmful microorganisms, in contrast to their disease-susceptible counterparts. Furthermore, the network analysis was performed on rhizosphere-associated microorganisms, including both bacteria and fungi. The networks of association recovered from YR exhibited greater complexity, robustness, and density, regardless of Foc inoculation. Following Foc infection in the YR rhizosphere, there was a notable increase in the dominant bacterium NA13, which is also a hub taxon in the microbial network. Reintroducing NA13 into the soil significantly improved disease resistance in the susceptible ZG variety, by directly inhibiting Foc and triggering defense mechanisms in the roots.ConclusionsThe rhizosphere microbial communities of these two cabbage varieties are markedly distinct, with the introduction of the pathogen eliciting significant alterations in their microbial networks which is correlated with susceptibility or resistance to soil-borne pathogens. Furthermore, we identified a rhizobacteria species that significantly boosts disease resistance in susceptible cabbages. Our results indicated that the induction of resistance genes leading to varied responses in microbial communities to pathogens may partly explain the differing susceptibilities of the cabbage varieties tested to CFW.-meKq2qaHpqpKck3NvZ8m1Video

Virulence Adaptation by Rice Planthoppers and Leafhoppers to Resistance Genes and Loci: A Review.

In recent decades, research on developing and deploying resistant rice has accelerated due to the availability of modern molecular tools and, in particular, advances in marker-assisted selection. However, progress in understanding virulence adaptation has been relatively slow. This review tracks patterns in virulence adaptation to resistance genes (particularly Bph1, bph2, Bph3, and bph4) and examines the nature of virulence based on selection experiments, responses by virulent populations to differential rice varieties (i.e., varieties with different resistance genes), and breeding experiments that interpret the genetic mechanisms underlying adaptation. The review proposes that varietal resistance is best regarded as a combination of minor and major resistance traits against which planthoppers develop partial or complete virulence through heritable improvements that are reversable or through evolutionary adaptation, respectively. Agronomic practices, deployment patterns, and herbivore population pressures determine the rates of adaptation, and there is growing evidence that pesticide detoxification mechanisms can accelerate virulence adaptation. Research to delay adaptation has mainly focused on gene pyramiding (i.e., including ≥ two major genes in a variety) and multilines (i.e., including ≥ two resistant varieties in a field or landscape); however, these strategies have not been adequately tested and, if not managed properly, could inadvertently accelerate adaptation compared to sequential deployment. Several research gaps remain and considerable improvements in research methods are required to better understand and manage virulence adaptation.

SCREENING OF COTTON (GOSSYPIUM HIRSUTUM L.) GERMPLASM AGAINST COTTON LEAF CURL VIRUS (CLCUV)

Cotton Leaf Curl Virus (CLCuV) is a devastating disease affecting cotton production worldwide, particularly in South Asia and Africa transmitted by the whitefly (Bemisia tabaci). CLCuV infection leads to severe symptoms, including leaf curling, vein thickening, stunted growth, and significant yield losses. Developing resistant cotton varieties is the most suitable strategy for managing CLCuV, given the limitations and environmental concerns associated with chemical controls. This study aimed to evaluate the resistance and susceptibility of different cotton varieties to CLCuV under natural field conditions and artificially infected condition using a disease severity scale ranging from 0 (highly resistant) to 5 (susceptible). A total of five cotton varieties, were assessed at three critical growth stages: vegetative, flowering, and boll formation. Disease severity, and yield components were recorded to determine extent of resistance of each variety. The results indicated that genotypes and treatments had significant variation in control compared to T1. According to DSI, NIAB-852 was scored as resistant with 10% infected leaves. FH-142 and CIM-496 were scored as tolerant according to DSI with 10-25% infection in leaves. NIAB Karishma and CIM-448 were scored as moderately susceptible with 50-75% infection. All genotypes had significant reduction in number of bolls, boll weight and seed cotton yield in T1 than control. These findings provide valuable insights into the effectiveness of existing cotton germplasm against CLCuV and highlight the need for continuous evaluation and development of resistant varieties. The study highlights the importance of generating resistant cultivars, thereby ensuring sustainable cotton production.

Root Infection and Minituber Yield Response to Powdery Scab in Plant Growth Chamber Conditions

Powdery scab, caused by the soil borne Plasmodiophorid Spongospora subterranea f. sp. subterranea (Sss), is an increasing concern. Developing resistant varieties with enduring resistance is crucial for sustainable disease management. However, the lack of a consistent infection assay for Sss hindered effective evaluation of disease symptoms, including root gall formation and tuber lesions. This study introduces a reliable method for assessing Sss pathogenicity using a sand/potting mixture in a controlled-environment plant growth chamber. Potato plants were inoculated with three types of inocula sourced from root galls, infested soil, and scab-like tube lesions. All inocula successfully induced root galls and tuber lesions, with the tuber lesion-derived inoculum producing the highest number of root galls. Additionally, the method demonstrated a marked impact on tuber yield, weight, and size in both highly susceptible and moderately susceptible cultivars. These findings underscore the efficacy of this infection assay as a robust tool for evaluating Sss pathogenicity. This method holds promise for screening potato germplasm to develop resistant varieties against powdery scab.