Figure - uploaded by Vaibhav K. Singh
Content may be subject to copyright.
Indian isolates of A. candida collected from B. juncea hosts along with the retrieved sequences from NCBI used for comparison
Source publication
To generate information on variability in the pathogen causing white rust disease in Brassica species and their ability to infect Brassica juncea genotypes, thirteen isolates of Albugo candida infecting B. juncea and one isolate of Wilsonia bliti infecting Amaranthus blitum were collected from different rapeseed-mustard growing regions of India. Th...
Contexts in source publication
Context 1
... COX2 and ten ITS sequences with a nucleotide length of 531 and 829 bases, respectively, were used for sequence alignments along with the other A. candida sequences retrieved from the NCBI for comparison (Table 1). Clustal W algorithm was used to perform the multiple sequence alignment. ...Context 2
... the ten isolates of A. candida were inoculated in the same set of conditions. Isolates of A. candida were designated by a two-letter code (AC-code) followed by a hyphen and a listing of those locations (short name) from where the isolate was collected (Table 1). The statistically significant different isolates of A. candida were categorized as physiological race of A. candida and same were nominated based on the specific host like-AcRBj-1 (Albugo candida Race B. juncea-1), AcRBj-2 (Albugo candida Race B. juncea-2) and so on. ...Context 3
... is an urgent need to address this complexity in the pathogen and also to identify an internationally standardized set of host differentials against each host species. In this study, the degrees of variability within the A. candida isolates from different geographical Biplot of different variables loaded on PC1 and PC2 showing their contribution towards total variation regions of India were being investigated based on morphological characters and molecular markers. Also, the nature of the pathogenic reaction of such isolates was tested against a set of different B. juncea lines. ...Context 4
... COX2 and ten ITS sequences with a nucleotide length of 531 and 829 bases, respectively, were used for sequence alignments along with the other A. candida sequences retrieved from the NCBI for comparison (Table 1). Clustal W algorithm was used to perform the multiple sequence alignment. ...Context 5
... the ten isolates of A. candida were inoculated in the same set of conditions. Isolates of A. candida were designated by a two-letter code (AC-code) followed by a hyphen and a listing of those locations (short name) from where the isolate was collected (Table 1). The statistically significant different isolates of A. candida were categorized as physiological race of A. candida and same were nominated based on the specific host like-AcRBj-1 (Albugo candida Race B. juncea-1), AcRBj-2 (Albugo candida Race B. juncea-2) and so on. ...Context 6
... is an urgent need to address this complexity in the pathogen and also to identify an internationally standardized set of host differentials against each host species. In this study, the degrees of variability within the A. candida isolates from different geographical Biplot of different variables loaded on PC1 and PC2 showing their contribution towards total variation regions of India were being investigated based on morphological characters and molecular markers. Also, the nature of the pathogenic reaction of such isolates was tested against a set of different B. juncea lines. ...Citations
... However In the current study, none of the assessed genotypes showed complete resistance to infection, aligning with Awasthi et al. [12] findings that emphasized the susceptibility of key B. juncea varieties in India to white rust. The diverse responses of different genotypes to pathogens, varying in susceptibility, may stem from the complex interplay of resistance gene expression and the genetic background affecting genotype-pathogen interactions, as emphasized by Singh et al. [13]. The dynamics of how hosts and pathogens interact are significantly shaped by both macro and micro environmental factors, ultimately influencing the disease's severity, as discussed by Tamang et al. [14]. ...
The increasing prominence of rapeseed-mustard on the global stage as vital oilseed crop is attributed to its high yield, low moisture requirements, cost effective production, and adoptability to diverse farming condition indicating the potential for a forthcoming yellow revolution role in India's oilseed production, facing challenges from various factors affecting yield and seed quality. Notably, white rust stands out as a significant biotic stressor, causing substantial losses in both yield and seedily, 17–34% yield particularly in oil content. To address this, utilizing resistant varieties is the most cost-effective and environmentally friendly approach for disease management. However, the available resistant sources are limited. In a recent study during the Rabi seasons of 2021-22 and 2022-23, thirty rapeseed mustard genotypes were assessed under white rust prevalent conditions. Out of 30 genotypes tested, none were found to be free of white rust disease infection and none were classified as resistant. However,11genotypes were registered as as moderately resistance, while, 19 genotypes fell under the were in the susceptible category. Promisingly, some genotypes exhibited resistance to white rust, offering potential for developing superior cultivars to effectively manage the disease in regions where mustard cultivation is prevalent. Aims: The study aimed to evaluate 30 rapeseed-mustard genotypes during the Rabi sessions of 2021-22 and 2022-23, focusing on their resistance to white rust. The primary objective was to identified genotypes with potential resistant traits, contributing to the development of superior cultivars for effective white rust management in regions where rapeseed-mustard cultivation is prominent. Study Design: Randomized Block Design. Place and Duration of Study: Experimental field of the Department of Plant Pathology, College of Agriculture, BUAT, Banda session 2021-22 and 2022-23. Results and Conclusion: None of the tested genotypes were found to be entirely free from white rust infection, and none of these achieved under resistance. However, the study identified 11 genotypes as moderately resistance and 19 genotypes fell into the susceptible category. Despite the challenges posed by white rust, sum genotypes demonstrated resistance, offering promising potential for the development of advanced cultivars. This finding holds significant for regions where rapeseed-mustard cultivation faces the threat of white rust, providing the basis for future efforts enhancing crop resilience and productivity.
... However In the current study, none of the assessed genotypes showed complete resistance to infection, aligning with Awasthi et al. [12] findings that emphasized the susceptibility of key B. juncea varieties in India to white rust. The diverse responses of different genotypes to pathogens, varying in susceptibility, may stem from the complex interplay of resistance gene expression and the genetic background affecting genotype-pathogen interactions, as emphasized by Singh et al. [13]. The dynamics of how hosts and pathogens interact are significantly shaped by both macro and micro environmental factors, ultimately influencing the disease's severity, as discussed by Tamang et al. [14]. ...
The increasing prominence of rapeseed-mustard on the global stage as vital oilseed crop is attributed to its high yield, low moisture requirements, cost effective production, and adoptability to diverse farming condition indicating the potential for a forthcoming yellow revolution role in India's oilseed production, facing challenges from various factors affecting yield and seed quality. Notably, white rust stands out as a significant biotic stressor, causing substantial losses in both yield and seedily, 17-34% yield particularly in oil content. To address this, utilizing resistant varieties is the most cost-effective and environmentally friendly approach for disease management. However, the available resistant sources are limited. In a recent study during the Rabi seasons of 2021-22 and 36 2022-23, thirty rapeseed mustard genotypes were assessed under white rust prevalent conditions. Out of 30 genotypes tested, none were found to be free of white rust disease infection and none were classified as resistant. However,11genotypes were registered as as moderately resistance, while, 19 genotypes fell under the were in the susceptible category. Promisingly, some genotypes exhibited resistance to white rust, offering potential for developing superior cultivars to effectively manage the disease in regions where mustard cultivation is prevalent. Aims: The study aimed to evaluate 30 rapeseed-mustard genotypes during the Rabi sessions of 2021-22 and 2022-23, focusing on their resistance to white rust. The primary objective was to identified genotypes with potential resistant traits, contributing to the development of superior cultivars for effective white rust management in regions where rapeseed-mustard cultivation is prominent. Study Design: Randomized Block Design. Place and Duration of Study: Experimental field of the Department of Plant Pathology, College of Agriculture, BUAT, Banda session 2021-22 and 2022-23. Results and Conclusion: None of the tested genotypes were found to be entirely free from white rust infection, and none of these achieved under resistance. However, the study identified 11 genotypes as moderately resistance and 19 genotypes fell into the susceptible category. Despite the challenges posed by white rust, sum genotypes demonstrated resistance, offering promising potential for the development of advanced cultivars. This finding holds significant for regions where rapeseed-mustard cultivation faces the threat of white rust, providing the basis for future efforts enhancing crop resilience and productivity.
... Another study [5] reported that brucellosis infection in livestock results in economic losses of around Rs 9212 crores. The cost of treatment of infectious diseases increased for the development of resistance against the used drugs in bacteria [6,7], parasites [8], fungi [9] and others. Investment of inadequate funds for the development of newer drugs [10] and the development of quick resistance to the drugs [11] are accelerating the problems. ...
... However, our results are not in the agreement with the findings of Chand et al. (2022) where they reported six mustard genotypes as highly resistant against white rust while evaluating 25 mustard genotypes with same disease indexing parameters. In some of the other studies, including Singh et al. (2021) found 12 genotypes, of B. juncea having immune type response at the cotyledonary stage. Similarly, in a separate investigation, five genotypes of B. juncea were reported highly resistant under field conditions. ...
... Awasthi et al. (2012) reported that almost all the important varieties of B. juncea being grown in India were susceptible to white rust. The broad variety in how different genotypes react to pathogens in terms of susceptibility to disease may be caused by the varied expression of resistance gene(s) and genetic background of genotypes that influences genotypepathogen interaction (Singh et al., 2021). The dynamics of host-pathogen interaction are greatly influenced by both macro and micro environment, which in turn has an impact on the severity of the disease (Tamang et al., 2022). ...
Mustard is an important oilseed crop in India. Various biotic factors are responsible for yield reduction as well as seed quality in mustard. Among different biotic stresses, white rust causes yield loss and quality in mustard up to a great extent. White rust not only degrades seed quality but also significantly lowers its oil content. As it is distinguished that, among various disease management tactics, use of resistant varieties is the best choice owing to cost-effectiveness and environment friendly approach. However, till now only few resistant sources against this disease has been reported. Therefore, in the present investigation, 75 Indian mustard genotypes have been evaluated in field under epiphytotic conditions during Rabi 2021-22. Some of the genotypes showed resistance against white rust disease. These resistance sources may be helpful to develop superior cultivar (s) for managing white rust disease where mustard cultivation is dominant.
... Wild Brassicaceae members such as B. fruticulosa and Thlaspi arvense have also been found to be resistant to white rust, whereas few species of genus Diplotaxis and Sinapis are reported as moderately resistant [26,27]. Although several Brassica species have been reported to carry white rust resistance genes, rapid evolutionary pathways of pathogen overcome the prevailing host resistance due to the occurrence of a high level of selection pressure in the present day mustard based cropping system, therefore searching for new resistance gene(s) is always a necessary basic and continuous process [16,18]. In the unpredictable climatic change and global warming, inbuilt resistance became imperative to stabilize and sustain the yield potential of Indian mustard cultivars under different growing conditions in India. ...
... In the present study, six genotypes (Pusa Karishma, PDZ-3, BIO YSR, Heera, BEC-144, Donskaja) of Indian mustard were found highly resistant (PDI = 0) under artificial and natural epiphytotic conditions against the A. candida Ac-Dli isolate, highlighting the continuous stability of resistance gene(s) present in these genotypes. In previous studies, Singh et al. [16] reported 12 genotypes, including Pusa Karishma, PDZ-3, BIO YSR, BEC-144, and Donskaja, of B. juncea, having immune type response (score = 0) against Ac-Dli isolate at the cotyledonary stage under controlled epiphytotic conditions. Likewise, five genotypes, including BEC-144, Heera and BIO YSR of B. juncea were found highly resistant at true leaf stage under field conditions [32]. ...
... In the present study, 19 genotypes were categorized from moderately susceptible to highly susceptible groups based on disease severity under both natural and artificial screening conditions ( Table 1), highlighting that these genotypes do not possess any resistance gene(s), therefore the pathogen establishes very well due to compatible pathogen-host interaction leading to heavy incidence of disease. Similarly, Singh et al. [16] reported that 13 out of 30 genotypes of B. juncea studied by them have been reported to be highly susceptible (score = 6) to Ac-Dli isolate at cotyledonary stage under controlled conditions. The wide variation in susceptible disease reaction of different genotypes against pathogens might be due to the differential expression of resistance gene(s) and genetic background of genotypes that affects genotype-pathogen interaction [16]. ...
White rust [Albugo candida (Pers. Ex. Lev) Kuntze] is an important oomycetes disease of
Indian mustard [Brassica juncea (L.) Czern & Coss] that causes a drastic reduction in seed yield and quality when the conditions are favorable. A set of 25 Indian mustard genotypes were screened against A. candida Delhi isolate (Ac-Dli) under both controlled and natural epiphytotic conditions. Out of 25, only six genotypes (Pusa Karishma, PDZ-3, Heera, BEC-144, BIO YSR, and Donskaja) were found highly resistant in both environments. To study the inheritance of resistance, four resistant genotypes (BEC-144, BIO YSR, Pusa Karishma, and Donskaja) were crossed with three susceptible genotypes (PM-24, Pusa Vijay, and MSTWR-17-15) in a definite design. The parents, F1, F2, and BC1F1 (F1 backcrossed with susceptible parent) generations were screened under both artificially controlled
and natural epiphytotic conditions and the results indicated that the resistance in BIO YSR, BEC-144, and Pusa Karishma is governed by a single dominant gene, but more than one dominant gene is responsible for resistance in Donskaja. A test of an allelism conducted on the F2 population derived by crossing resistant (BEC-144) × resistant (BIO YSR) genotypes indicated that the gene imparting resistance to Ac-Dli isolate in the resistant parents BEC-144 and BIO YSR is the same and they are allelic to each other. Therefore, in broader terms, the information generated in the present study will be useful in Indian mustard breeding programs for the development of durable resistant cultivars.
... It was evident from the study that the pathogenicity and host ranges of the A. candida were affected by the differences in geographical locations. The presence of a high diversity within the A. candida isolates from various geographical regions of the country was reported based on morphological and molecular study and four physiological races were being identified based on their differential reactions on a set of thirty B. juncea genotypes (Singh et al. 2020). Australian A. candida race 9 (Ac 9) from B. oleracea var. ...
To test the responsiveness of Albugo candida isolates causing white rust disease in Brassica juncea, nine different cruciferous hosts were cross-inoculated with five isolates of A. candida and one isolate of Wilsonia bliti collected from B. juncea and Amaranthus blitum, respectively. Isolate Ac-Dli was able to infect B. oleracea var. botrytis, B. oleracea var. capitata, and B. rapa subsp. rapa, while Ac-Mghy and Ac-Pnt were able to infect B. rapa subsp. rapa. Ac-Bgpt and Ac-Wltn isolates were able to cross infect B. oleracea var. capitata and B. oleracea var. gemmifera, respectively. Isolate of W. bliti from Amaranthus host was unable to establish a disease reaction to any of the cruciferous hosts due to the non-host nature of this species against the tested crucifers. Among the five A. candida isolates, Ac-Pnt was found to be the most virulent and Ac-Wltn to be the least virulent. Our study suggests the responsiveness of A. candida isolates from different geographical regions to other related cruciferous hosts which can act as an alternate host in the field condition. Therefore, the breeding strategies for the development of resistant varieties of B. juncea against white rust disease should also include other related cruciferous hosts wherever A. candida is reported pathogen.
Albugo candida, responsible for causing white rust disease, is a significant fungal pathogen leading to substantial yield and economic loss in Indian mustard. Therefore, it is necessary to explore intrinsic resistance in Brassica juncea germplasm for suppression of this disease. In the present study, phenotyping of exotic and indigenous collections of Brassica juncea was done against thirteen diverse A. candida isolates in cotyledon and true leaf plants under controlled conditions and in adult plants on field at different locations during three consecutive mustard crop seasons (2019–2022). Among 311 lines screened of B. juncea, 59 germplasms were found immune under artificial and field screening against various isolates of A. candida. Five accessions, EC766193, IC265495, EC766061, EC766595 and IC443623 of B. juncea were identified to express immune response for six of the pathogenic isolates, whereas, for rest of the isolates they expressed high to moderate resistance. Moreover, correlation study showed positively co-related resistance levels among adult plant and true leaf stage of development in B. juncea (r = 0.859, p < 0.01). The GGE biplot elucidated 69.4% of the total variation and visually displayed the resistance and stability for B. juncea accessions against white rust disease. These new sources of host resistance for virulent pathotypes of A. candida are critically important and will help to create a strong credential for discerning and mapping of resistance linked gene/QTL and to sustainably manage this disease in India.
Oilseed brassica has become instrumental in securing global food and nutritional security. B. juncea, colloquially known as Indian mustard, is cultivated across tropics and subtropics including Indian subcontinent. The production of Indian mustard is severely hampered by fungal pathogens which necessitates human interventions. Chemicals are often resorted to as they are quick and effective, but due to their economic and ecological unsustainability, there is a need to explore their alternatives. The B. juncea-fungal pathosystem is quite diverse as it covers broad-host range necrotrophs (Sclerotinia sclerotiorum), narrow-host range necrotrophs (Alternaria brassicae and A. brassicicola) and biotrophic oomycetes (Albugo candida and Hyaloperonospora brassica). Plants ward off fungal pathogens through two-step resistance mechanism; PTI which involves recognition of elicitors and ETI where the resistance gene (R gene) interacts with the fungal effectors. The hormonal signalling is also found to play a vital role in defense as the JA/ET pathway is initiated at the time of necrotroph infection and SA pathway is induced when the biotrophs attack plants. The review discuss the prevalence of fungal pathogens of Indian mustard and the studies conducted on effectoromics. It covers both pathogenicity conferring genes and host-specific toxins (HSTs) that can be used for a variety of purposes such as identifying cognate R genes, understanding pathogenicity and virulence mechanisms, and establishing the phylogeny of fungal pathogens. It further encompasses the studies on identifying resistant sources and characterisation of R genes/quantitative trait loci and defense-related genes identified in Brassicaceae and unrelated species which, upon introgression or overexpression, confer resistance. Finally, the studies conducted on developing resistant transgenics in Brassicaceae have been covered in which chitinase and glucanase genes are mostly used. The knowledge gained from this review can further be used for imparting resistance against major fungal pathogens.
Mustard is an important oilseed crop in India and affected by various biotic factors including Alternaria blight. Alternaria blight not only degrades seed quality but also significantly lowers its oil content. As it is notable that, among various disease management approaches, use of resistant varieties is the best option owing to cost effective and environment friendly approach. However, till now only few resistant sources against this disease has been reported. Therefore, in the present investigation 75 Indian mustard genotypes have been evaluated under field conditions during Rabi 2021-22. Some of the genotypes showed resistance against this disease. These resistance sources will be helpful in developing superior cultivar (s) for managing Alternaria blight where Indian mustard cultivation is prevalent.
The white rust caused by Oomycetes Albugo candida (Pers.) Kuntze infects cruciferous crops and results in huge economic loss at a global level. To cope with this problem, identification of a resistance source against morphologically and pathologically diverse white rust is one of the necessary objectives to improve the cultivar’s yield. In this study, eighteen diverse Brassica genotypes including one susceptible variety Varuna were evaluated against twelve (A) candida isolates collected from the different geographical locations in Indian. Based on the PCA analysis, the morphological characters loaded, were found to contribute 58.6% and 38.3% of total variability through pustule size and sporangia size, respectively. Whereas latent period only contributes 3% of total variability among WRI. While comparing Brassicaceae hosts, no disease symptoms was observed on two Brassica spp. viz. (B) napus cv. GSL-1 and B. carinata cv. DLSC-1 that consistently showed complete resistance against all WR isolates. Also, the two DH B. juncea mutant lines C66 and C69 showed a promising level of resistance against A. candida where C66 was found completely resistant against 09 white rust isolates (WRI) except susceptible to WRI-K isolate while, C69 was found to be second best in terms of resistance against WRI-WB isolate followed by 08 other isolates except WRI-K, WRI-M and WRI-S. With changing habitats and unavailability of a significant solution, these findings would help in identifying genetic resistance against a widened horizon enhancing the scope of deploying white rust resistance in the susceptible Indian mustard genotypes.
