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Susceptibility to low-temperature injury and diseases is a major concern associated with ornamental camellia production. To comprehensively understand their growth, cold-hardiness, flowering, and disease resistance, 24 camellia (Camellia spp. and hybrids) cultivars and selections were evaluated inMcMinnville, TN, USA (USDA plant hardiness zone 7a). During Mar 2011, camellias were planted in the field plots. Plant height and canopy width weremeasured annually from 2011 to 2019, and low-temperature damage was recorded in 2014 and 2023. The flowering duration was recorded each year from 2011 to 2020. The Camellia Yellow Mottle Virus, monochaetia leaf spot (Monochaetia sp.), edema, flower blight (Ciborinia camelliae), and flower spot (Botrytis cinerea) severity (% affected) were evaluated from Oct to Nov in 2016 and 2017. The season-long area under the disease progress curve (AUDPC) was calculated. Cultivars Arctic Snow and Pink Icicle exhibited the greatest height, and Autumn Spirit, Elaine Lee, Arctic Snow, and Survivor had the widest canopy width, whereas Shishigashira had the lowest height and canopy width. 'April Remembered', 'April Rose', 'Arctic Snow', 'Ashton's Ballet', 'Autumn Carnival', 'Autumn Spirit', 'Elaine Lee', 'Survivor', andC. chekiangoleosa selection were least affected by winter low temperatures, whereas 'Korean Snow', 'One Alone', C. sasanqua selection, 'Pink Icicle', and 'Shishigashira' were severely damaged. 'Arctic Snow' flowered most reliably (6 of 8 years), whereas 'April Remembered', 'April Rose', 'Ashton's Ballet', 'Autumn Spirit', and 'Survivor' flowered five times. 'Korean Fire', 'Classic Pink', 'Maroon Mist', and 'Spring's Promise' displayed the highest virus severity and AUDPC. 'Arctic Snow', C. sasanqua selection, and the C. chekiangoleosa selection had no viral symptoms. C. sasanqua selection and 'Red Aurora' were significantly impacted by edema disorder, with severity ratings of ~43%and 26%, respectively. Monochaetia leaf spot severity was highest in 'Red Aurora' and 'Spring's Promise', whereas 'Anacostia', 'Arctic Snow', 'Ashton's Ballet', 'Autumn Spirit', 'Classic Pink', 'Kuro Delight', 'One Alone', 'Pink Icicle', 'Shishigashira', and'Survivor' exhibited the leastmonochaetia leaf spot severity and AUDPC. Flower blight and flower spot were observed only in 'Arctic Snow' and 'Survivor'. These findings will aid landscapers and nursery growers with selecting andmanaging camellia cultivars effectively. [ABSTRACT FROM AUTHOR]

Susceptibility to low-temperature injury and diseases is a major concern associated with ornamental camellia production. To comprehensively understand their growth, cold-hardiness, flowering, and disease resistance, 24 camellia (Camellia spp. and hybrids) cultivars and selections were evaluated in McMinnville, TN, USA (USDA plant hardiness zone 7a). During Mar 2011, camellias were planted in the field plots. Plant height and canopy width were measured annually from 2011 to 2019, and low-temperature damage was recorded in 2014 and 2023. The flowering duration was recorded each year from 2011 to 2020. The Camellia Yellow Mottle Virus, monochaetia leaf spot (Monochaetia sp.), edema, flower blight (Ciborinia camelliae), and flower spot (Botrytis cinerea) severity (% affected) were evaluated from Oct to Nov in 2016 and 2017. The season-long area under the disease progress curve (AUDPC) was calculated. Cultivars Arctic Snow and Pink Icicle exhibited the greatest height, and Autumn Spirit, Elaine Lee, Arctic Snow, and Survivor had the widest canopy width, whereas Shishigashira had the lowest height and canopy width. ‘April Remembered’, ‘April Rose’, ‘Arctic Snow’, ‘Ashton’s Ballet’, ‘Autumn Carnival’, ‘Autumn Spirit’, ‘Elaine Lee’, ‘Survivor’, and C. chekiangoleosa selection were least affected by winter low temperatures, whereas ‘Korean Snow’, ‘One Alone’, C. sasanqua selection, ‘Pink Icicle’, and ‘Shishigashira’ were severely damaged. ‘Arctic Snow’ flowered most reliably (6 of 8 years), whereas ‘April Remembered’, ‘April Rose’, ‘Ashton’s Ballet’, ‘Autumn Spirit’, and ‘Survivor’ flowered five times. ‘Korean Fire’, ‘Classic Pink’, ‘Maroon Mist’, and ‘Spring’s Promise’ displayed the highest virus severity and AUDPC. ‘Arctic Snow’, C. sasanqua selection, and the C. chekiangoleosa selection had no viral symptoms. C. sasanqua selection and ‘Red Aurora’ were significantly impacted by edema disorder, with severity ratings of ∼43% and 26%, respectively. Monochaetia leaf spot severity was highest in ‘Red Aurora’ and ‘Spring’s Promise’, whereas ‘Anacostia’, ‘Arctic Snow’, ‘Ashton’s Ballet’, ‘Autumn Spirit’, ‘Classic Pink’, ‘Kuro Delight’, ‘One Alone’, ‘Pink Icicle’, ‘Shishigashira’, and ‘Survivor’ exhibited the least monochaetia leaf spot severity and AUDPC. Flower blight and flower spot were observed only in ‘Arctic Snow’ and ‘Survivor’. These findings will aid landscapers and nursery growers with selecting and managing camellia cultivars effectively.

The oil of Camellia spp. has become a well-known high-quality edible oil because of its rich nutrition. It is of great significance to breed fine varieties of Camellia spp. for the sustainable growth of the Camellia spp. industry. This study mainly evaluated the quality and antioxidant capacity of the camellia seed from several sources. The fatty acid composition and main active components of 40 kinds of C. oleifera, C. vietnamensis, C. osmantha, and C. gigantocarpa seeds, and so on, from different regions, were tested using GC–MS and HPLC. The quality of different Camellia spp. germplasm resources was comprehensively evaluated using multiple indices. The unsaturated fatty acid content and the antioxidant capacity of C. vietnamensis from Hainan were higher than those of C. oleifera Abel. In addition, there were a few differences in the fatty acid compositions of Camellia spp. oil from different species. Correlation analysis confirmed that rutin, total saponin, total flavonoids, squalene, and vitamin E were strongly correlated to the antioxidant capacity of Camellia spp. In the comprehensive evaluation, the best quality and strongest antioxidant activity were found for Chengmai Dafeng (C. vietnamensis). These methods in the study were applied for the first time for the quality evaluation of the Camellia spp. species. This study provided new insights into the quality evaluation of the Camellia spp. species, thus facilitating further development of variety breeding along with quality evaluation. [ABSTRACT FROM AUTHOR]

The oil of Camellia spp. has become a well-known high-quality edible oil because of its rich nutrition. It is of great significance to breed fine varieties of Camellia spp. for the sustainable growth of the Camellia spp. industry. This study mainly evaluated the quality and antioxidant capacity of the camellia seed from several sources. The fatty acid composition and main active components of 40 kinds of C. oleifera, C. vietnamensis, C. osmantha, and C. gigantocarpa seeds, and so on, from different regions, were tested using GC–MS and HPLC. The quality of different Camellia spp. germplasm resources was comprehensively evaluated using multiple indices. The unsaturated fatty acid content and the antioxidant capacity of C. vietnamensis from Hainan were higher than those of C. oleifera Abel. In addition, there were a few differences in the fatty acid compositions of Camellia spp. oil from different species. Correlation analysis confirmed that rutin, total saponin, total flavonoids, squalene, and vitamin E were strongly correlated to the antioxidant capacity of Camellia spp. In the comprehensive evaluation, the best quality and strongest antioxidant activity were found for Chengmai Dafeng (C. vietnamensis). These methods in the study were applied for the first time for the quality evaluation of the Camellia spp. species. This study provided new insights into the quality evaluation of the Camellia spp. species, thus facilitating further development of variety breeding along with quality evaluation.

Plant associated endophytic actinobacteria may contribute to plant growth and defense by direct or indirect methods. Our aim was to evaluate the plant growth promoting and antifungal activities of endophytic actinobacteria associated with Camellia spp. and related genera, Eurya to find potent plant growth promoting strains that could be applied in future microbe based bioformulations. We isolated 46 endophytic actinobacteria based on morphological characteristics of the isolates. 16S rRNA gene sequence analysis showed that the strains represented nine actinobacterial genera, Nocardia, Amycolatopsis, Streptomyces, Pseudonocardia, Kribbella, Actinomadura, Microbispora, Rothia and Saccharomonospora. In vitro functional characterization of the isolates for plant growth promoting (PGP) traits revealed many potent PGP isolates such as, SA1 and S43 which showed all the tested PGP traits, i.e., phosphate solubilization, indole-3-acetic acid (IAA), ammonia, siderophore and chitinase production. Out of the 46 endophytic actinobacteria isolates, 21 showed inhibition against atleast one test fungal phytopathogen and, isolates SA25 and SA29 exhibited broad spectrum antifungal activity against all the tested phytopathogens. Most of the endophytic actinobacteria isolates having antifungal activity were positive for the presence of chitinase, NRPS (Non-ribosomal peptides synthetase) or PKS-1 (Polyketide Synthase) gene, suggesting the presence of distinctive mechanisms to inhibit the growth of pathogenic plant fungi. ARDRA (Amplified Ribosomal DNA Restriction analysis) and BOX-PCR fingerprinting analysis of the potent isolates with antagonistic activity grouped the isolates into 5 and 4 separate clusters, respectively. In addition, an assessment using bonitur scale revealed the top ranked isolates based on their PGP and biocontrol traits. Further detection of IAA production by the top ranked actinobacterial isolates namely, SA1, T1LA3 and S85 by using thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) was done. Endophytic actinobacteria isolates, namely, SA1, T1LA3, and SA14 were further tested for their efficacy in promoting the growth of commercial tea clones, namely, TV1, TV9, TV18, and TV22 in nursery conditions. All the endophytic isolates tested showed significant differences (P ≤ 0.05) in terms of plant growth promoting parameters in the treated plants compared to untreated control and may, thus be, deemed as potential candidates for application in bioformulations for tea growth.

Plant associated endophytic actinobacteria may contribute to plant growth and defense by direct or indirect methods. Our aim was to evaluate the plant growth promoting and antifungal activities of endophytic actinobacteria associated with Camellia spp. and related genera, Eurya to find potent plant growth promoting strains that could be applied in future microbe based bioformulations. We isolated 46 endophytic actinobacteria based on morphological characteristics of the isolates. 16S rRNA gene sequence analysis showed that the strains represented nine actinobacterial genera, Nocardia, Amycolatopsis, Streptomyces, Pseudonocardia, Kribbella, Actinomadura, Microbispora, Rothia and Saccharomonospora. In vitro functional characterization of the isolates for plant growth promoting (PGP) traits revealed many potent PGP isolates such as, SA1 and S43 which showed all the tested PGP traits, i.e., phosphate solubilization, indole-3-acetic acid (IAA), ammonia, siderophore and chitinase production. Out of the 46 endophytic actinobacteria isolates, 21 showed inhibition against atleast one test fungal phytopathogen and, isolates SA25 and SA29 exhibited broad spectrum antifungal activity against all the tested phytopathogens. Most of the endophytic actinobacteria isolates having antifungal activity were positive for the presence of chitinase, NRPS (Non-ribosomal peptides synthetase) or PKS-1 (Polyketide Synthase) gene, suggesting the presence of distinctive mechanisms to inhibit the growth of pathogenic plant fungi. ARDRA (Amplified Ribosomal DNA Restriction analysis) and BOX-PCR fingerprinting analysis of the potent isolates with antagonistic activity grouped the isolates into 5 and 4 separate clusters, respectively. In addition, an assessment using bonitur scale revealed the top ranked isolates based on their PGP and biocontrol traits. Further detection of IAA production by the top ranked actinobacterial isolates namely, SA1, T1LA3 and S85 by using thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) was done. Endophytic actinobacteria isolates, namely, SA1, T1LA3, and SA14 were further tested for their efficacy in promoting the growth of commercial tea clones, namely, TV1, TV9, TV18, and TV22 in nursery conditions. All the endophytic isolates tested showed significant differences (P ≤ 0.05) in terms of plant growth promoting parameters in the treated plants compared to untreated control and may, thus be, deemed as potential candidates for application in bioformulations for tea growth. [ABSTRACT FROM AUTHOR]

Ciborinia camelliae Kohn is the causal agent of camellia flower blight, a severe disease that affects plants of the genus Camellia L. This review provides an overview on the studies published in international as well as in specialized journals and Ph.D. theses during the last seventeen years. It summarizes the existing information and highlights the available options for effective chemical, biological, and agronomical approaches that can guide future efforts in limiting disease incidence on flowering camellias. [ABSTRACT FROM AUTHOR]

Morphological diversity of three Camellia (Theaceae) taxa conserved in an ex situ gene bank was studied and the importance of different descriptors in categorising accessions into distinct groups was also determined. Twelve accessions were characterised using 15 morphological descriptors of IPGRI guidelines. The results of principal component analysis (PCA) on morphological characters showed that the first two principal components accounted for 44.77 % of the total variance. In the evaluated quantitative characters, all three taxa had a coefficient of variation (CV) greater than 24.85%, and within the taxon the CV was greater than 9.59%. The qualitative characters showed a wide range of variations and yielded significant differences (p

A new genus and two new species of mites in the family Eriophyidae, Theaphyes rapaneae gen. n. and sp. n. which is found on the type host Rapanea neriifolia (Sieb. et Zucc.) Mez (Myrsinaceae) and Paracaphyllisa theacea sp. n., are described and illustrated. They are vagrants on the tea plant Camellia sinensis (L.) Kuntze and no apparent symptoms were detected. A key to the eriophyoid mites including thirteen species associated with tea plants all over the world is provided. [ABSTRACT FROM AUTHOR]

Tea mosquito (Helopeltis theivora) is a serious pest in tea (Camellia sinensis) growing regions, causing severe crop loss. Identification of markers associated with tea-mosquito resistance is necessary to develop cultivars tolerant to tea mosquito from the available germplasm. This study was conducted to identify random amplified polymorphic DNA (RAPD) markers associated with tolerance against tea mosquito. The RAPD markers were then sequenced and converted into sequence-characterized amplified region (SCAR) markers. A total of 138 decamer primers were used to screen genomic DNA from four susceptible and four relatively tolerant tea cultivars. Only three RAPD markers (OPW-03725, OPT-01625, and OPG-11750) were linked to tea-mosquito resistance. These markers were converted into co-dominant SCAR markers, Rht1, Rht2, and Rht3. This is the first study reporting the development of markers for tea-mosquito resistance. These markers can be used as an important tool to screen tea cultivars for tea-mosquito resistance/susceptibility. [ABSTRACT FROM PUBLISHER]

Abstract: This study uses anthocyanins in the red flowers of section Camellia as taxonomic markers to investigate the phenetic relationships among 33 wild species from China, Taiwan, and Japan. The 25 anthocyanins from section Camellia produced 38 pigment patterns that serve as phenetic markers. Principal Component Analysis (PCA) indicated that the attachment of one or two glucoses to the cyanidin-core structure at the 3- or the 3- and 5-positions, respectively, was the most influential pattern against the first factor, Z 1. In addition, two alternative pigment patterns, acylated or non-acylated, and the structural isomerism (cis- or trans-) of the p-coumaroyl group were relatively significant patterns. Ward’s minimum-variance cluster analysis (WMVCA) produced a dendrogram that consisted of two sub-clusters. One sub-cluster (A) was constructed by species that have mainly two types of anthocyanins: 3,5-di-O-β-glucosides (Camellia saluenensis) and sambubioside of cyanidin (Camellia reticulata). The other sub-cluster (B) was made up of the 3-O-β-glucosides of cyanidin (Camellia japonica) and delphinidin (Camellia hongkongensis), with a higher proportion of the 3-O-β-galactosides (Camellia mairei and Camellia boreali-yunnanica). The former group showed a higher proportion of acylation, over 63%, but with the exception of Camellia azalea. The latter group showed less than 52% acylation, but with the exception of C. hongkongensis and C. boreali-yunnanica. PCA and WMVCA indicated that the greater the amount of di-O-glycosides and acylation, the more primitive anthocyanin traits the species possess. Based on these results, in conjunction with geographical and literary information, the data suggest that the Xinan district is the site/center of origin for the red-flowered Camellia species of which both C. saluenensis and C. reticulata have the most primitive anthocyanin traits. [Copyright &y& Elsevier]

• A complex virome was identified by NGS analyses in Camellia japonica. • Two new emaraviruses were characterized in camellia plants. • Recently characterized CRSaV1 and CRSaV2 were detected in Italian camellia samples. • Accurate molecular analyses allowed the correct reconstruction of CjaEVs RdRp genes. • Camellia betaflexiviruses' coat proteins showed hyperconservation at amino acid level. Camellia japonica plants manifesting a complex and variable spectrum of viral symptoms like chlorotic ringspots, necrotic rings, yellowing with necrotic rings, yellow mottle, leaves and petals deformations, and flower color-breaking have been studied since 1940, mainly by electron microscopic analyses; however, a strong correlation between the symptoms and one or more well-characterized viruses was never verified. In this work, samples collected from symptomatic plants were analyzed using the next-generation sequencing technique, and a complex virome composed of members of the Betaflexiviridae and Fimoviridae families was identified. In particular, the genomic fragments typical of the emaravirus group were organized in the genomes of two new emaraviruses species, tentatively named Camellia japonica–associated emaravirus 1 and 2. They are the first emaraviruses described in camellia plants and found in symptomatic plants. At the same time, in both symptomatic and asymptomatic plants, five betaflexivirus isolates were detected that, based on amino acid sequence comparisons, can be considered two new isolates of the recently characterized camellia ringspot–associated virus 1 and 2 (CRSaV-1/2). These recently identified betaflexiviruses associated with C. japonica disease show an unusual hyper-conservation of the coat protein at the amino acid level. The GenBank/EMBL/DDBJ accession numbers of the sequences reported in this paper are MN385581, MN532567, MN532565, MN385582, MN532566, MN385573, MN385577, MN385574, MN385578, MN385575, MN385579, MN385576, MN385580, MN557024, MN557025, MN557026, MN557027, and MN557028. [ABSTRACT FROM AUTHOR]

A new genus and two new species of mites in the family Eriophyidae, Theaphyes rapaneae gen. n. and sp. n. which is found on the type host Rapanea neriifolia (Sieb. et Zucc.) Mez (Myrsinaceae) and Paracaphyllisa theacea sp. n., are described and illustrated. They are vagrants on the tea plant Camellia sinensis (L.) Kuntze and no apparent symptoms were detected. A key to the eriophyoid mites including thirteen species associated with tea plants all over the world is provided.