PMID- 37081598
OWN - NLM
STAT- Publisher
LR  - 20230420
IS  - 0191-2917 (Print)
IS  - 0191-2917 (Linking)
DP  - 2023 Apr 20
TI  - First report of Colletotrichum grevilleae causing fruit anthracnose of 
      pomegranate in Taiwan.
LID - 10.1094/PDIS-02-23-0395-PDN [doi]
AB  - Pomegranate (Punica granatum L.), native to northern India, is a popular fruit 
      crop. In Taiwan, pomegranate is mainly cultivated in the mid and southern regions 
      including Waipu, Taichung and Neipu, Pingtung. However, diseases affecting 
      production and quality of pomegranate are largely understudied in Taiwan where 
      gray mold and Cercospora leaf spot of pomegranate were ever reported (Hsieh, 
      1978; Hsieh and Wu, 1989). Pomegranate fruit (cv. Tunisia) showing anthracnose 
      symptoms were found in a commercial pomegranate farm of 0.4 ha in Waipu 
      (N24.33111, E120.68978) in August 2020. Around 40% fruit were infected and 
      displayed symptoms of brown sunken lesions with indistinct edges typically 
      occurred at the fruit ripening stage (supplementary Fig. S1). To isolate the 
      pathogen, diseased exocarps were surface sterilized with 1% NaOCl followed by 70% 
      ethanol. Surface-sterilized tissues were placed on potato dextrose agar (PDA) and 
      incubated at 25 degrees C. A fungus was consistently isolated from diseased fruit, and 
      five isolates (PGCo1, WP1, WP2, WP3, and WP4) were obtained. When cultured on PDA 
      25℃ under near UV light (360 nm) with a 12-h:12-h light/dark cycle for 10 days, 
      the isolates initially produced white hyphae and subsequently formed dark gray to 
      olivaceous black colonies with white edge, and no conidiomata was observed 
      (supplementary Fig. S1). Conidia were usually aseptate, hyaline, cylindrical to 
      ellipsoid and obtuse at either one or both ends (supplementary Fig. S1), and 
      measured 16.0 +/- 1.6 (11.4-18.9) x 5.6 +/- 0.5 (4.5-6.9) mum (n = 100). The isolates 
      were further identified by sequence comparison and phylogenetic analysis of 
      concatenated partial sequences of the internal transcribed spacer (ITS) of the 
      rDNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin (TUB2), 
      chitin synthase 1 (CHS-1), actin (ACT) and calmodulin (CAL) genes (Weir et al., 
      2012). The sequences were deposited in the GenBank under accession numbers 
      ON849040-ON849044 and ON862106-ON862130. BLASTn searches showed the ITS sequences 
      of the pomegranate isolates were 100% identical to that of C. grevilleae CBS 
      132879T (NR_163525). The ACT, GAPDH and TUB2 sequences of the isolates were 100%, 
      100% and 99.57%, respectively, identical to those of C. grevilleae CBS 132879T 
      (KC296941, KC297010 and KC297102). The CHS-1 sequences were 99.67-100% identical 
      to that of C. grevilleae CBS 132879T (KC296987). The CAL sequences showed 91.50% 
      and 100% identity with those of C. grevilleae CBS 132879T (KC296963) and C. 
      grossum CAUG7T (KP890147), respectively, both members of the C. gloeosporioides 
      species complex. Multilocus sequence analysis of the combined data was conducted 
      using MEGA X software (Kumar et al., 2018). The five isolates were clustered with 
      C. grevilleae CBS 132879T, indicating that the pomegranate isolates are C. 
      grevilleae (Supplementary Fig. S2). For pathogenicity test, 6 symptomless ripe 
      pomegranate fruit (cv. Tunisia) were surface sterilized, wounded by stabbing a 
      sterile needle, and inoculated with a conidial suspension (10 mul each, 1x106 
      conidia/ml) of PGCo1. Sterile water was used as control. The inoculated fruit 
      were kept in a moist plastic chamber (>95% relative humidity, 25 +/- 2 degrees C) in 
      darkness. The experiment was performed twice. Seven days post inoculation, the 
      artificially inoculated fruit showed anthracnose symptoms of sunken brown lesions 
      indistinguishable from the natural infection. The control remained symptomless. 
      The same fungus was repeatedly isolated from the symptomatic fruit, fulfilling 
      Koch's postulates. Prior to this study, only the ex-type strain of C. grevilleae 
      was collected from root and collar rot of Grevillea sp. (Liu et al., 2013). This 
      is the first report of C. grevilleae causing anthracnose on pomegranate in 
      Taiwan. Since no fungicide has been approved for pomegranate cultivation in 
      Taiwan, future study is necessary to develop a management strategy against this 
      disease.
FAU - Huang, Chien-Jui
AU  - Huang CJ
AD  - National Chiayi University, 63107, Plant Medicine, No. 300, Syuefu Rd., Chiayi 
      City, Taiwan, 60004; chienjui.huang@mail.ncyu.edu.tw.
FAU - Tsai, Shuen-Huang
AU  - Tsai SH
AD  - Fengshan Tropical Horticultural Experiment Station, 56090, Plant Protection, 
      Kaohsiung, Taiwan; tsh@tari.gov.tw.
LA  - eng
PT  - Journal Article
DEP - 20230420
PL  - United States
TA  - Plant Dis
JT  - Plant disease
JID - 9882809
SB  - IM
OTO - NOTNLM
OT  - Causal Agent
OT  - Crop Type
OT  - Etiology
OT  - Fruit
OT  - Fungi
OT  - Subject Areas
OT  - tree fruits
EDAT- 2023/04/21 00:42
MHDA- 2023/04/21 00:42
CRDT- 2023/04/20 23:46
PHST- 2023/04/21 00:42 [medline]
PHST- 2023/04/21 00:42 [pubmed]
PHST- 2023/04/20 23:46 [entrez]
AID - 10.1094/PDIS-02-23-0395-PDN [doi]
PST - aheadofprint
SO  - Plant Dis. 2023 Apr 20. doi: 10.1094/PDIS-02-23-0395-PDN.