תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםCyclamen (Cyclamen persicum) is native to Europe and is distributed in Mediterranean countries, western Asia, and northern Africa (Anonymous 2016). Cyclamen is a protected ornamental species in Israel, with the flowering season taking place from December to March. In December 2015, necrotic leaf spots with concentric circles were observed on 40% of the plants growing in two commercial nurseries in central Israel (Hod Hasharon and Kfar Rut). Twelve diseased leaves from six plants were collected from both nurseries, sectioned into small pieces (3 to 5 mm), surface sterilized (20 s in 70% EtOH, followed by 3 min in 1% NaOCl and rinsed with sterile water) and plated on PDA at 25°C for pathogen isolation. A total of 12 single-spore morphologically identical isolates were obtained from each sampling. Mycelium of the isolates appeared grayish-white in color containing a deep orange conidial mass in the center. Conidia were hyaline with rounded ends, measuring 14.3 to 21.1 × 3.9 to 6.6 (mean = 17.3 × 5.4, n = 55) µm in size. Growth rate was 9.3 mm/day. DNA sequencing of the Apn2/Mat IGS (ApMat) marker using the AM-F and AM-R primer pair (Silva et al. 2012) was conducted for two isolates (GCy01 and GCy03) (GenBank accessions KU664036, KU664037). Maximum parsimony analysis was conducted using PAUPv.4b10 and compared with reference sequences (Sharma et al. 2013). Both the isolates clustered with Colletotrichum theobromicola type strain (ICMP 18649) sequences. Based on morphological characteristics and phylogenetic analysis, the pathogen was identified as C. theobromicola. Koch’s postulates were confirmed by inoculating healthy detached leaves and those of intact 1-month potted plants, with 10 µl suspensions (1 × 107 conidia/ml) at wounded (pin-pricked) and unwounded sites. Control leaves were mock-inoculated with sterile distilled water. Moist conditions were maintained for 1 week for inoculated detached leaves (laid upon sterile wet filter paper) and plants (sprayed with sterile water every alternate day). The pathogenicity assays were conducted in five replicates containing seven leaves each. After 7 days, leaf spots typical for anthracnose in Cyclamen were observed on detached as well as intact leaves, while control leaves remained healthy and symptomless. Disease symptoms were more severe at wounded sites. The pathogen was reisolated from leaf spot symptoms of inoculated leaves and confirmed as C. theobromicola by morphology and PCR. C. theobromicola was initially described as a pathogen of Theobroma cacao from Panama, and has been reported from other hosts such as Stylosanthes and Olea spp. from Australia, Limonium sp. from Israel, Annona sp. from Mexico, Acca sp. from New Zealand, Punica sp. from India, and Fragaria and Quercus spp. from the United States (Farr and Rossman 2016). To the best of our knowledge, this is the first report of C. theobromicola from Cyclamen, one of the most serious pathogens affecting this crop in Israel.
Cyclamen (Cyclamen persicum) is native to Europe and is distributed in Mediterranean countries, western Asia, and northern Africa (Anonymous 2016). Cyclamen is a protected ornamental species in Israel, with the flowering season taking place from December to March. In December 2015, necrotic leaf spots with concentric circles were observed on 40% of the plants growing in two commercial nurseries in central Israel (Hod Hasharon and Kfar Rut). Twelve diseased leaves from six plants were collected from both nurseries, sectioned into small pieces (3 to 5 mm), surface sterilized (20 s in 70% EtOH, followed by 3 min in 1% NaOCl and rinsed with sterile water) and plated on PDA at 25°C for pathogen isolation. A total of 12 single-spore morphologically identical isolates were obtained from each sampling. Mycelium of the isolates appeared grayish-white in color containing a deep orange conidial mass in the center. Conidia were hyaline with rounded ends, measuring 14.3 to 21.1 × 3.9 to 6.6 (mean = 17.3 × 5.4, n = 55) µm in size. Growth rate was 9.3 mm/day. DNA sequencing of the Apn2/Mat IGS (ApMat) marker using the AM-F and AM-R primer pair (Silva et al. 2012) was conducted for two isolates (GCy01 and GCy03) (GenBank accessions KU664036, KU664037). Maximum parsimony analysis was conducted using PAUPv.4b10 and compared with reference sequences (Sharma et al. 2013). Both the isolates clustered with Colletotrichum theobromicola type strain (ICMP 18649) sequences. Based on morphological characteristics and phylogenetic analysis, the pathogen was identified as C. theobromicola. Koch’s postulates were confirmed by inoculating healthy detached leaves and those of intact 1-month potted plants, with 10 µl suspensions (1 × 107 conidia/ml) at wounded (pin-pricked) and unwounded sites. Control leaves were mock-inoculated with sterile distilled water. Moist conditions were maintained for 1 week for inoculated detached leaves (laid upon sterile wet filter paper) and plants (sprayed with sterile water every alternate day). The pathogenicity assays were conducted in five replicates containing seven leaves each. After 7 days, leaf spots typical for anthracnose in Cyclamen were observed on detached as well as intact leaves, while control leaves remained healthy and symptomless. Disease symptoms were more severe at wounded sites. The pathogen was reisolated from leaf spot symptoms of inoculated leaves and confirmed as C. theobromicola by morphology and PCR. C. theobromicola was initially described as a pathogen of Theobroma cacao from Panama, and has been reported from other hosts such as Stylosanthes and Olea spp. from Australia, Limonium sp. from Israel, Annona sp. from Mexico, Acca sp. from New Zealand, Punica sp. from India, and Fragaria and Quercus spp. from the United States (Farr and Rossman 2016). To the best of our knowledge, this is the first report of C. theobromicola from Cyclamen, one of the most serious pathogens affecting this crop in Israel.
