A Review about Cotton Leaf Curl Viral Disease and Its Control Strategies in Pakistan

Cotton leaf curl virus (CLCuV) in Pakistan is the most serious threat to cotton crops of last two decades. This diseases causes a huge losses not only to the cotton crops but also the economy of Pakistan is under threat. This problem of Cotton Leaf Curl Disease (CLCuD) is still under discussion among the researchers since it first appeared in 1967 and in 1992-93, it came in epidemic form. The dilemma of CLCuD caused decline in the yield down to 9.05 million bales and 8.04 million bales in 1993-94 in Pakistan. For developing resistant cultivars against the virus to screen against CLCuD, different disease inducing methods such as grafting, delayed sowing and whitefly mediated transfer are used. The epidemiology of diseases is changed by abiotic factors specifically temperature and plant age. Management of CLCuD is the only option that can command the disease in various ways inclusive of change in sowing dates, crop nutrition, cultural practices, vector control, buffer crops and systemic poisoning of cotton seed by seed treatment will make the cotton crop safe in initial 40-50 days after sowing. Biotechnology can also help in controlling this disease through transcriptional gene silencing. By using biotechnological tools broad spectrum resistance can be introduced against all viruses present in the field

Estimation of Gene Action, Heritability and Pattern of Association among Different Yield Related Traits in Upland Cotton

A random mating design comprising 6 varieties (FH-142, MS-DK, IUB-63, KZ-189, FB-3159, and VH-300) and F1 crosses was used to check gene action for yield contributing traits in upland cotton. Heritability and correlation were calculated from F3 populations of the cross CRS-456times%253BJumbo okra. The randomized complete block design was used in both experiments with three replication at the Department of Plant Breeding and Genetics, University of Agriculture Faisalabad, Pakistan during 2015-2017. In both experiments, analysis of variance indicated significant variation present among the accessions of the upland cotton for all the traits (plant height, sympodial and monopodial branches, nodes number of 1st sympodial branch, height of 1st sympodial branch, bolls per plant, boll weight, lint weight, seed cotton yield, seed index, lint percentage, lint index, seeds per boll, fiber fineness, fiber strength, fiber length and fiber uniformity) under study. Mean values of all genotypes were significantly different from each other for all the traits studied. All the parameters manifested positive correlation with seed cotton yield except plant height, monopodia per plant, nodes number of 1st sympodia, height of 1st sympodia, bolls per plant, seed index and lint index. The inheritance of all the traits in F1 crosses was generally controlled by overdominance gene action except monopodial branches, nodes number of 1st sympodial branch, height of 1st sympodial branches, boll weight, fiber length and fiber uniformity that were partially controlled under additive gene action. Epistasis was not found to be involved in any of the traits. Estimation of broad sense heritability (h2 b. s) in F3 populations were high (60-97%25) for all the traits under study. Results suggested form heritability and correlation that these traits can be improved either through appropriate selection method or hybrid breeding programme

High-throughput sequencing in plant disease management: a comprehensive review of benefits, challenges, and future perspectives

Abstract High-throughput sequencing (HTS) has instigated a paradigm shift in plant pathology, showcasing its transformative role in the management of plant diseases. As a powerful tool, HTS aids in identifying pathogens and enhances disease management strategies by detecting novel and emerging pathogens, tracking disease outbreaks, and contributing to developing disease-resistant cultivars. Despite these benefits, the implementation of HTS faces obstacles due to the complexity of data interpretation and economic factors that affect its widespread adoption. This comprehensive review summarizes the strengths, limitations, and opportunities associated with using HTS in managing plant diseases. The article also delves into the prospects of HTS, incorporating technological advancements, synergy with complementary methodologies, capacity-building initiatives, and the development of best practices and guidelines. By acknowledging and addressing these obstacles while harnessing the full capabilities of HTS, we advocate for a refined approach to managing plant diseases. This approach is critical for ensuring global food security, especially in the context of a growing global population and climate change

Characterization of the wheat cultivars against Tilletia controversa Kühn, causal agent of wheat dwarf bunt

AbstractWheat is one of the most important staple crops. Tilletia controversa Kühn is the causal agent of wheat dwarf bunt. In this study, a resistant wheat cultivar displayed significantly higher expression of pathogenesis-related genes than a susceptible cultivar at 7 days post inoculation (DPI) with T. controversa. Similarly, the expression was high in the resistant cultivar after exogenous application of phytohormones, including salicylic acid. The expression of pathogenesis-related genes, especially chitinase 4, was high in the resistant cultivar, while LPT-1 was down regulated after T. controversa infection. Callose deposition was greater in the resistant cultivar than in the susceptible cultivar at 10 DPI. Confocal microscopy was used to track the fungal hyphae in both cultivars in anther and ovary cells. The anthers and ovaries of the susceptible cultivar were infected by T. controversa at 7 and 15 DPI. There were no fungal hyphae in anther and ovary cells in the resistant cultivar until 10 and 23 DPI, respectively. Moreover, anther length and width were negatively influenced by T. controversa at 16 DPI. The plant height was also affected by fungal infection. Ultimately, resistance to T. controversa was achieved in cultivars via the regulation of the expression of defense-related and pathogenesis-related genes.</jats:p

Methyljasmonate and salicylic acid contribute to the control of Tilletia controversa Kühn, causal agent of wheat dwarf bunt

AbstractTilletia controversa Kühn (TCK) is the causal agent of dwarf bunt of wheat, a destructive disease in wheat-growing regions of the world. The role of Meja, SA and Meja + SA were characterized for their control of TCK into roots, coleoptiles and anthers. The response of the defence genes PR-10a, Catalase, COI1-1, COII-2 and HRin1 was upregulated by Meja, SA and Meja + SA treatments, but Meja induced high level of expression compared to SA and Meja + SA at 1, 2, and 3 weeks in roots and coleoptiles, respectively. The severity of TCK effects in roots was greater at 1 week, but it decreased at 2 weeks in all treatments. We also investigated TCK hyphae proliferation into coleoptiles at 3 weeks and into anthers to determine whether hyphae move from the roots to the upper parts of the plants. The results showed that no hyphae were present in the coleoptiles and anthers of Meja-, SA- and Meja + SA-treated plants, while the hyphae were located on epidermal and sub-epidermal cells of anthers. In addition, the severity of hyphae increased with the passage of time as anthers matured. Bunted seeds were observed in the non-treated inoculated plants, while no disease symptoms were observed in the resistance of inducer treatments and control plants. Plant height was reduced after TCK infection compared to that of the treated inoculated and non-inoculated treatments. Together, these results suggested that Meja and SA display a distinct role in activation of defence genes in the roots and coleoptiles and that they eliminate the fungal pathogen movement to upper parts of the plants with the passage of time as the anthers mature.</jats:p

Wheat Varietal Response to Tilletia controversa J. G. Kühn Using qRT-PCR and Laser Confocal Microscopy

Tilletia controversa J. G. Kühn is a causal organism of dwarf bunt in wheat. Understanding the interaction of wheat and T. controversa is of practical and scientific importance for disease control. In this study, the relative expression of TaLHY and TaPR-4 and TaPR-5 genes was higher in a resistant (Yinong 18) and moderately resistant (Pin 9928) cultivars rather than susceptible (Dongxuan 3) cultivar at 72 h post inoculation (hpi) with T. controversa. Similarly, the expression of defensin, TaPR-2 and TaPR-10 genes was observed higher in resistant and moderately resistant cultivars after exogenous application of phytohormones, including methyl jasmonate, salicylic acid, and abscisic acid. Laser confocal microscopy was used to track the fungal hyphae in the roots, leaves, and tapetum cells, which of susceptible cultivar were infected harshly by T. controversa than moderately resistant and resistant cultivars. There were no fungal hyphae in tapetum cells in susceptible cultivar after methyl jasmonate, salicylic acid and abscisic acid treatments. Moreover, after T. controversa infection, the pollen germination was of 80.06, 58.73, and 0.67% in resistant, moderately resistant and susceptible cultivars, respectively. The above results suggested that the use using of resistant cultivar is a good option against the dwarf bunt disease.</jats:p

Characterization of histological changes at the tillering stage (Z21) in resistant and susceptible wheat plants infected by Tilletia controversa Kühn

Abstract Background Dwarf bunt, which is caused by Tilletia controversa Kühn, is a soilborne and seedborne disease that occurs worldwide and can lead to 70% or even total losses of wheat crops. However, very little information is available about the histological changes that occur in dwarf bunt-resistant and dwarf bunt-susceptible wheat plants at the tillering stage (Z21). In this study, we used scanning electron microscopy and transmission electron microscopy to characterize the histological changes at this stage in resistant and susceptible wheat cultivars infected by T. controversa. Results Using scanning electron microscopy, the root, stem, and leaf structures of resistant and susceptible cultivars were examined after T. controversa infection. The root epidermal and vascular bundles were more severely damaged in the susceptible T. controversa-infected plants than in the resistant plants. The stem cell and longitudinal sections were much more extensively affected in susceptible plants than in resistant plants after pathogen infection. However, slightly deformed mesophyll cells were observed in the leaves of susceptible plants. With transmission electron microscopy, we found that the cortical bundle cells and the cell contents and nuclei in the roots were more severely affected in the susceptible plants than in the resistant plants; in the stems and leaves, the nuclei, chloroplasts, and mesophyll cells changed significantly in the susceptible plants after fungal infection. Moreover, we found that infected susceptible and resistant plants were affected much more severely at the tillering stage (Z21) than at the seedling growth stage (Z13). Conclusion Histological changes in the wheat roots, stems and leaves were much more severe in T. controversa-infected susceptible plants than in infected resistant plants at the tillering stage (Z21). </jats:sec

Effects of Tilletia foetida on Microbial Communities in the Rhizosphere Soil of Wheat Seeds Coated with Different Concentrations of Jianzhuang

AbstractTilletia foetida (syn. T. laevis) leads to wheat common bunt, a worldwide disease that can lead to 80% yield loss and even total loss of production, together with degrading the quality of grains and flour by producing a rotten fish smell. To explore the potential microbial community that may contribute to the control of soil- and seed-borne pathogens, in this study, we analyzed the effects of the plant pathogenic fungus T. foetida on rhizosphere soil microorganisms in wheat seeds coated with different concentrations of a fungicide (Jianzhuang) used to control the disease. To analyze the bacterial and fungal abundance in T. foetida-infected and mock-infected plants, the microorganisms were sequenced using high-throughput HiSeq 2500 gene sequencing. The results showed that bacterial communities, including Verrucomicrobia, Patescibacteria, Armatimonadetes, Nitrospirae, Fibrobacteres, Chlamydiae, and Hydrogenedentes, and fungal communities, including Basidiomycota and Ciliophora, were more prevalent in the mock group than in the T. foetida-infected group, which may contribute to the control of wheat common bunt. Moreover, cluster and PCoA analysis revealed that replicates of the same samples were clustered together, and these results were also found in the distance index within-group analysis for bacterial and fungal communities in the T. foetida-infected and mock groups.</jats:p

Metabolomics Analysis of Tilletia Controversa Kühn Infected and Non-infected Grains of Wheat

Abstract Dwarf bunt caused by the pathogen Tilletia controversa Kühn is one of the most serious quarantine disease of winter wheat. Metabolomics studies provide detailed information about biochemical changes at the cell and tissue level of the plants. In the present study, liquid chromatography/mass spectrometry (LC/MS) metabolomic approach was used to investigate the changes in the grains metabolomics of T. controversa infected and non-infected samples. PCA analysis suggested that T. controversa infected and non-infected samples scattered separately during the interaction. LC/MS analysis showed that 62 different metabolites were recorded in the grains, among them total of 34 metabolites were up-regulated and 28 metabolite were down-regulated. The prostaglandins (PGs) and 9-hydroxyoctadecaenoic acids (9-HODEs) are fungal toxin related substances and their expression significantly increased in T. controversa infected grains. Additionally, the concentration of cucurbic acid and octadecatrienoic acid were changed significantly after pathogen infection, which has great role in plant defense. The eight different metabolic pathways activated during the T. controversa and wheat plants interactions including phenylalanine metabolism, isoquinoline alkaloid biosynthesis, starch and sucrose metabolism, tyrosine metabolism, sphingolipid metabolism, arginine and proline metabolism, alanine, aspartate, glutamate metabolism, and tryptophan metabolism.</jats:p