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Tea (Camellia sinensis (L) O. Kuntze) is a plantation crop, grown commercially in Asia, Africa and South America. Among biotic threats to tea production, diseases caused by fungal pathogens are most significant. Worldwide, tea plants are challenged by several root, stem, and foliar diseases. Foliar diseases, blister blight, grey blight, and brown b...
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... cankers have been reported from Sri Lanka, India, and Bangladesh ( Ahmad et al. 2016;Barthakur 2011;Sinniah 2018). Phomopsis canker attacks stem and twigs, kills branches, and, after moving downward in the plant, causes decay of the entire bush. A yield loss of 40 to 50% was reported due to twig dieback caused by Fusarium solani (Mart.) Sacc ( Fig. 7A and B) in Taiwan ( Muraleedharan and Chen 1997), and collar and branch cankers in central Africa ( Rattan and Sobrak 1976). Phomopsis canker can cause the death of 2-to 8-yearold bushes, significantly reducing establishment of tea plantations (Balasuriya 2008). The fungi that cause stem and branch cankers enter the stems, kill the ...
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Citations
... Tea (Camellia sinensis (L) O. Kuntze), belonging to the Family Theaceae, is a cash crop extensively cultivated in regions spanning Asia, Africa, and South America. Prominent tea-producing countries include India, China, Kenya, Sri Lanka, Vietnam, and Indonesia [1]. The global tea trade holds a substantial value of approximately USD 9.5 billion, serving as a crucial source of export earnings. ...
Derived from the Camellia sinensis (L.) Kuntze plant, tea is the most widely consumed natural beverage in the world. Tea is a perennial woody plant. Monoculturing tea on a large scale makes it susceptible to many perennial and seasonal diseases. The leaves, stems, and roots of tea plants are susceptible to fungal, bacterial, and viral pathogens. Tea is predominantly grown in Asian and African regions; hence, conventional methods including symptomology and signs, and microbiological and microscopic methods are mainly used in disease diagnosis and pathogen identification. Accurate and rapid identification of diseases and patho- gens is imperative for the sustainability of tea plantations. Thus, the technological advancement in plant disease diagnosis also embraces the global tea industry. This chapter discusses new technological advances in tea disease diagnosis, focusing on molecular biological methods, whole genome sequencing, and remote sensing and image analysis methods. Further, it highlights the challenges in disease diagnosis as a perennial woody plant and pins down available opportunities that could be successfully adopted to overcome the issues.
... Tea shrubs provide a congenial niche for more than thousands of arthropod pests and pathogens that result in significant crop loss and damage to plantation crops (Bhattacharyya and Sarmah 2018;Pandey et al. 2021;Bhattacharyya et al. 2023a). According to Manosathiyadevan et al. (2017) and Scott and Orians (2018) insect herbivores can adapt dynamically to attack all parts of the tea bush, especially the foliage, leading to significant crop losses (11-55%), globally, if left uncontrolled. ...
Looper caterpillars including the Biston (= Buzura) suppressaria (Lepidoptera: Geometridae) and Hyposidra talaca (Lepidoptera: Geometridae), are recorded as major defoliating pests in tea [Camellia sinensis (L.) O. Kuntze], are responsible for a decline in tea bush quality, a decrease in yield, and extensive foliage deterioration. The hasty and unlawful usage of chemical pesticides for looper control has adverse effects, such as the deterioration of natural soil fertility, disturbance of beneficial plant-microbe interactions, and an elevated risk of pesticide resistance. Undesired pesticide residues are frequently detected in the final tea product as pesticides have been applied to eradicate looper caterpillars in tea crop. In the current investigation, spore suspensions of two entomopathogenic fungi, Beauveria bassiana (MG547581) and Metarhizium anisopliae (MG547580), have been employed in vitro to evaluate their effectiveness in controlling three distinct stages of the life cycle of looper caterpillar. The highest rates of microbial infection and pest mortality were measured in the prepupal stage of each pest during in vitro incubation studies and bioassay. Pest mortality up to 90% was recorded with a spore load of 3 × 107 cfu/mL at the prepupal stage, while mortality in adults was up to 70% and influenced by species variations. The lowest median lethal dose (LD50) values of M. anisopliae were recorded as 1.1 × 106 (prepupae), 1.9 × 106 (pupae) and 3.2 × 106 (adult) against H. talaca and against B. suppressaria both the entomopathogens showed equal LD50 values in all distinct stages like prepupae (5.3 × 105), pupae (3.2 × 106) and adult (7.6 × 104). Further, median lethal time (LT50) values increased gradually from prepupae, and pupae to adult, both in cases of H. talaca (3.69, 3.97 and 4.40 days in 3 × 107 cfu/mL of M. anisopliae) and B. suppressaria (4.30, 4.72 and 5.34 days in 3 × 107 cfu/mL of B. bassiana) due to entomopathogenesis. As eco-friendly and nonchemical options for tea looper caterpillar management appear to be limited, the current study explores putative microbial alternatives such as B. bassiana and M. anisopliae for the sustainable management of two significant defoliating pests of tea.
... The majority of the causal agents of Camellia sinensis diseases are known to be fungal species (Pandey et al. 2021(Pandey et al. , 2023. Brown blight (Colletotrichum camelliae Massee), leaf blotch (Colletotrichum sp.), horsehair blight (Marasmius crinis-equi. ...
... Brown blight (Colletotrichum camelliae Massee), leaf blotch (Colletotrichum sp.), horsehair blight (Marasmius crinis-equi. Müeller), blister blight (Exobasidium vexans Massee) and twig die-back and stem canker (Macrophoma theicola Petch) are few of common fungal diseases which severely affect the global tea production (Gadd 1949, Hainsworth 1952, Chen et al. 1982, Keith et al. 2006, Pandey et al. 2021. Pestalotioid species are known to be the most destructive pathogens of C. sinensis, especially as causal agents of grey blight, which has resulted in a considerable yield loss in many countries over the years (Ps. ...
Camellia sinensis (L.) Kuntze var. assamica (Miang tea) is widely distributed in northern Thailand due to its traditional and industrial attributes, including black tea and Miang production. In this study, two Pestalotioid taxa associated with C. sinensis leaf spots were collected in Mae Taeng district, Chiang Mai Province, Thailand. Species delineation was based on the evidence from morphological and multi-locus phylogenies using ITS, tub2 and tef1-α. Neopestalotiopsis saprophytica is herein reported as a new record on Camellia sinensis, while Pseudopestalotiopsis chinensis is recorded as a new geographical record from Thailand. The findings of this research have the potential to offer fresh insights into the two previously documented species within the existing fungal community associated with C. sinensis in Thailand. This, in turn, could enhance our comprehension of their interactions with the host plant in the times ahead.
... In several tea-producing countries, leaf, stem and root diseases are the most serious treats that affect the yield and quality of tea. Among the diseases, root rot is economically important problem in the tea production (Gayathri et al., 2020;Pandey et al., 2021), since it kills irrespective of trees age or vigor. From their nature, soil-borne pathogens like F. oxysporum is very difficult to manage once occur and can exist for several years by causing huge damage, especially on perennial crops. ...
... Tea, like other scrub plants, is vulnerable to various fungal diseases including blister blight caused by Exobasidium vexans (Sen et al. 2020;Pandey et al. 2021), brown blight caused by Colletotrichum spp. (Chen et al. 2015(Chen et al. , 2017, and grey blight caused by Pestalotiopsis-like species (Wang et al. 2019;Shahriar et al. 2022). ...
Tea (Camellia sinensis (L.) Kuntze) is a dicotyledonous woody shrub species widely cultivated to produce a beverage made from its leaves. Brown blight is a destructive foliar fungal disease that reduces tea production and degrades quality, resulting in lower market value. Typical brown blight symptoms observed in three commercial tea plantations in Malaysia were characterized as brownish to black lesions on young leaves. The lesions expanded with age, becoming darker and developing into necrotic cells. A total of 45 fungal isolates were isolated from brown blighted tea leaves and identified as Colletotrichum camelliae. Morphological characteristics coupled with universal spacer region and multigene phylogenetic relationships using the internal transcribed spacer (ITS), β-tubulin (tub2), and glyceraldehyde-3-phosphate dehydrogenase (gapdh) were used to accurately identify fungal isolates. The results of the pathogenicity test revealed that C. camelliae was responsible for causing brown blight disease of tea. This study highlights the occurrence of C. camelliae which causes tea brown blight in Malaysia. These findings may assist in disease monitoring, strict quarantine, and effective control management of diseased tea plants.
... China, leading the world in tea production, demonstrated a consistent upward trajectory from 2015 to 2022, reaching an impressive 3.35 million tons in 2022, marking a 5.88% year-on-year growth and reinforcing China's enduring dominance in the global tea industry. Despite this success, tea plants are confronted with significant biotic and abiotic stresses, affecting various plant parts and resulting in substantial crop losses worldwide, with reported reductions of up to 55% [6][7][8][9][10][11]. Addressing these challenges through comprehensive research and intervention is imperative for the sustained growth of global tea production. ...
Gray blight disease stands as one of the most destructive ailments affecting tea plants, causing significant damage and productivity losses. However, the dynamic roles of defense genes during the infection of gray blight disease remain largely unclear, particularly concerning their distinct responses in resistant and susceptible cultivars. In the pursuit of understanding the molecular interactions associated with gray blight disease in tea plants, a transcriptome analysis unveiled that 10,524, 17,863, and 15,178 genes exhibited differential expression in the resistant tea cultivar (Yingshuang), while 14,891, 14,733, and 12,184 genes showed differential expression in the susceptible tea cultivar (Longjing 43) at 8, 24, and 72 h post-inoculation (hpi), respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses highlighted that the most up-regulated genes were mainly involved in secondary metabolism, photosynthesis, oxidative phosphorylation, and ribosome pathways. Furthermore, plant hormone signal transduction and flavonoid biosynthesis were specifically expressed in resistant and susceptible tea cultivars, respectively. These findings provide a more comprehensive understanding of the molecular mechanisms underlying tea plant immunity against gray blight disease.
... Introduction Tang et al. BMC Microbiology (2024) 24:38 blight, twig dieback, stem cankers, and root rots are considered to be the most severe [4]. In particular, the genus Fusarium comprises soil-borne fungi known to cause wilt, leaf spot, collar canker, and dieback in tea plants [5,6]. ...
Background
Tea is one of the most widely consumed beverages in the world, with significant economic and cultural value. However, tea production faces many challenges due to various biotic and abiotic stresses, among which fungal diseases are particularly devastating.
Results
To understand the identity and pathogenicity of isolates recovered from tea plants with symptoms of wilt, phylogenetic analyses and pathogenicity assays were conducted. Isolates were characterized to the species level by sequencing the ITS, tef-1α, tub2 and rpb2 sequences and morphology. Four Fusarium species were identified: Fusarium fujikuroi, Fusarium solani, Fusarium oxysporum, and Fusarium concentricum. The pathogenicity of the Fusarium isolates was evaluated on 1-year-old tea plants, whereby F. fujikuroi OS3 and OS4 strains were found to be the most virulent on tea.
Conclusions
To the best of our knowledge, this is the first report of tea rot caused by F. fujikuroi in the world. This provides the foundation for the identification and control of wilt disease in tea plants.
... China is the world's largest tea producer and exporter, with an annual production of tea leaves exceeding 13 million tons in 2021, supporting the livelihoods of millions in the tea industry [1]. However, tea production faces persistent challenges from fungal diseases [2]. Pestalotiopsis-like species, known as the causal agents of gray blight disease in tea plants, are a highly destructive group of phytopathogens [3]. ...
... In severe cases, these lesions spread throughout the leaf, leading to defoliation [5]. Disease severity is exacerbated under warm and humid conditions, negatively impacting tea yield and quality [2]. Various Pestalotiopsis-like species have caused significant yield losses in major tea-producing countries like China, India and Japan [6][7][8]. ...
... Current disease management relies heavily on synthetic Metabolites 2023, 13, 1122 2 of 18 fungicides such as methyl benzimidazole carbamates and dithiocarbamates. However, these approaches come with high costs, environmental concerns and an increased risk of fungal resistance development [2,9,10]. Therefore, developing effective control measures requires a profound understanding of the defense mechanisms employed by the tea plant against the causal agent of gray blight disease. ...
Gray blight disease, which is caused by Pestalotiopsis-like species, poses significant challenges to global tea production. However, the comprehensive metabolic responses of tea plants during gray blight infection remain understudied. Here, we employed a multi-omics strategy to characterize the temporal transcriptomic and metabolomic changes in tea plants during infection by Pseudopestalotiopsis theae, the causal agent of gray blight. Untargeted metabolomic profiling with ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) revealed extensive metabolic rewiring over the course of infection, particularly within 24 h post-inoculation. A total of 64 differentially accumulated metabolites were identified, including elevated levels of antimicrobial compounds such as caffeine and (−)-epigallocatechin 3-gallate, as well as oxidative catechin polymers like theaflavins, theasinensins and theacitrins. Conversely, the synthesis of (+)-catechin, (−)-epicatechin, oligomeric proanthocyanidins and flavonol glycosides decreased. Integrated omics analyses uncovered up-regulation of phenylpropanoid, flavonoid, lignin biosynthesis and down-regulation of photosynthesis in response to the pathogen stress. This study provides novel insights into the defense strategies of tea plants against gray blight disease, offering potential targets for disease control and crop improvement.
... Moreover, the frequent occurrence of extreme weather also poses new challenges to tea farmers and scientists by, for instance, cold spells in spring (Hao et al., 2018), elevating risks of unusual droughts (Cook et al., 2015;Diffenbaugh et al., 2015). The management of biotic stresses (Das et al., 2021) and abiotic stresses (Tian et al., 2018;Pandey et al., 2021) during tea plant cultivation has drawn the attention of farmers and scientists worldwide due to the widespread cultivation of tea and its economic significance. Therefore, understanding of the response of tea plants under various stress conditions and their molecular mechanisms has become a key topic of interest. ...
... Diseases caused by fungal infection of the foliage are considered the most threatening due to their direct damage to production and non-negligible spread, including blister, blight, gray blight, and brown blight, etc. These diseases usually cause spots of varying shapes and colors on the leaves and ulcers and rots on stems and roots (Pandey et al., 2021). Insects can cause direct losses or cause dense reddish-brown spots on the leaves and lead to chlorosis of young leaves, depending on the form of their feeding (Tian et al., 2018). ...
... over a period of about one month (Rahimi et al., 2019;Chaeikar et al., 2020). Pest and disease damage can also lead to production losses of 20%-50% (Pandey et al., 2021). In addition, the effects of soil noxious ions, such as Zn, on tea plant yield show a promotive effect at low doses but a decrease in yield at high doses, which is similar to their effects on physiological indicators (Mukhopadhyay et al., 2013). ...
In the context of global climate change, tea plants are at risk from elevating environmental stress factors. Coping with this problem relies upon the understanding of tea plant stress response and its underlying mechanisms. Over the past two decades, research in this field has prospered with the contributions of scientists worldwide. Aiming in providing a comprehensive perspective of the research field related to tea plant stress response, we present a bibliometric analysis of this area. Our results demonstrate the most studied stresses, global contribution, authorship and collaboration, and trending research topics. We highlight the importance of flavonoid metabolites in tea plant stress response, particularly their role in maintaining redox homeostasis, yield, and adjusting tea quality under stress conditions. Further research on the flavonoid response under various stress conditions can promote the development of cultivation measures, thereby improving stress resistance and tea quality.
... Therefore, it is essential to study the diversity of rhizobacteria with growth promotion attributes in diverse cropping systems. Tea, scientifically known as Camellia sinensis (L.) O. Kuntze. is an important perennial beverage crop habitually grown in the North-Eastern and Eastern parts of India including North Bengal (Pandey et al., 2021). In North Bengal which further includes Dooars, Terai and Darjeeling, tea is cultivated in over 1,15,100 hectare land with annual production of 225.8 million kg ). ...
... In North Bengal which further includes Dooars, Terai and Darjeeling, tea is cultivated in over 1,15,100 hectare land with annual production of 225.8 million kg ). The perennial system and warm and humid climate make tea plants more prone to pests and diseases (Pandey et al., 2021). Extensive applications of agrochemicals in tea gardens to manage pests and diseases and to meet the global requirement of tea resulted in interchange of microbial populations associated with phylloplane and rhizosphere of tea crop (Bishnu et al., 2008;Cernava et al., 2019). ...
... Tea is cultivated as a major plantation crop in North Bengal. However, due to its perennial nature, high humidity, rainfall pattern and high temperature, the tea crop is attacked by several pests and diseases (Pandey et al., 2021). Tea growers are relying on synthetic pesticides and fertilizers to improve tea health; however, their regular application in tea cultivating areas has indirectly had a harmful impact on both plants and the environment as well as humans (Baibakova et al., 2019). ...
Rhizobacteria associated with cultivated crops are known to stimulate plant growth through various indirect or direct mechanisms. In recent years, the host list of plant growth promotion/promoting rhizobacteria has expanded to include bean, barley, cotton, maize, rice, vegetables, peanut, rice, wheat, and several plantation crops. However, interaction of rhizobacteria with tea plants of organic and conventional tea gardens is poorly understood. In the present study, rhizobacterial species associated with tea rhizosphere were isolated from 14 tea gardens located in North Bengal, India. In total, 16 rhizobacterial isolates isolated from collected soil samples were assessed for antagonistic and plant growth promotion/promoting activity under laboratory conditions. Molecular characterization based on sequencing of 16S rRNA gene revealed dominance of Bacillus with five species followed by Pseudomonas with two species. Interestingly, only one isolate was affiliated with actinobacteria, i.e., Microbacterium barkeri. Out of 16 isolates, isolates Bacillus subtilis OKAKP01, B. subtilis BNLG01, B. paramycoides BOK01, M. barkeri BPATH02, and Stenotrophomonas maltophilia BSEY01 showed highest growth inhibition against Fusarium solani (68.2 to 72.8%), Pseudopestalotiopsis theae (71.1 to 85.6%), and Exobasidium vexans (67.4 to 78.3%) causing respective Fusarium dieback, gray blight, and blister blight diseases in tea crop. Further, these five isolates also possessed significantly greater antifungal (siderophore producer, protease, chitinase, and cellulase activity) and plant growth promotion/promoting (indole-3-acetic acid production, ACC deaminase, ammonia, and phosphate solubilization) traits over other eleven rhizobacterial isolates. Therefore, these five isolates of rhizobacteria were chosen for their plant growth promotion/promoting activity on tea plants in nursery conditions. Results from nursery experiments revealed that these five rhizobacteria significantly improved growth rates of tea plants compared with the control. Therefore, this study suggests that these rhizobacteria could be used to formulate biopesticides and biofertilizers, which could be applied to sustainable tea cultivation to improve crop health and reduce disease attack.
