Crown disease (CD) is infecting oil palm in the early stages of the crop development. Previous studies showed that Fusarium species were commonly associated with CD. However, the identity of the species has not been resolved. This study was carried out to identify and characterize through morphological approaches and to determine the genetic diversity of the Fusarium species. 51 isolates (39%) of Fusarium solani and 40 isolates (31%) of Fusarium oxysporum were recovered from oil palm with typical CD symptoms collected from nine states in Malaysia, together with samples from Padang and Medan, Indonesia. Based on morphological characteristics, isolates in both Fusarium species were classified into two distinct morphotypes; Morphotypes I and II. Molecular characterization based on IGS-RFLP analysis produced 27 haplotypes among the F. solani isolates and 33 haplotypes for F. oxysporum isolates, which indicated high levels of intraspecific variations. From UPGMA cluster analysis, the isolates in both Fusarium species were divided into two main clusters with the percentage of similarity from 87% to 100% for F. solani, and 89% to 100% for F. oxysporum isolates, which was in accordance with the Morphotypes I and II. The results of the present study indicated that F. solani and F. oxysporum associated with CD of oil palm in Malaysia and Indonesia were highly variable.

Grapes (Vitis vinifera L.), one of the most valuable fruit crops in Pakistan, are grown primarily for fresh consumption. A survey of postharvest diseases was conducted during 2015-16 and 2016-17 in fruit packaging houses in Jhelum (32°56'22.3"N 73°43'31.4"E) and Chakwal (32°56'01.5"N 72°50'37.1"E) Districts of Punjab province. Prevalence of fruit rot was 100% after 3 to 5 days of post-harvest storage. Initial symptoms occurred mainly on wounded berries; fruit skin turned reddish brown, followed by lesion expansion and development of blue-green sporulation with white margins on the surface of lesions. Excised tissue segments (3 to 5 mm3) at the margins of lesions on 200 selected symptomatic berries were surface disinfected with 2% sodium hypochlorite for 1 min, rinsed three times in sterile distilled water, and blotted dry for 45 seconds. Disinfected segments were placed on Czapek yeast agar (CYA) and incubated at 25 ± 2°C. After one week, two different types of fungal colonies appeared. One type initially...

Strawberry (Fragaria × ananassa Duch.) has recently become an economically important fruit crop in Pakistan and is cultivated on approximately 1500 ha. A survey across Punjab, Khyber Pakhtunkhwa (KPK) provinces and Islamabad (Islamabad Capital territory) was conducted during March and April of 2015-2016 growing season revealed black leaf spot symptoms on strawberry leaves. Leaf spots were irregular in shape, 3 to 6 mm in diameter, and blackish brown. Disease incidence was found 17 to 55 % in visited fields. Portions of symptomatic leaf tissue (3 × 5 mm) were excised from the margins of lesions; surface disinfected with 2% sodium hypochlorite for 2 min, rinsed three times in sterile distilled water (SDW) and blotted dry. Leaf tissue was then placed on Czapek Dox agar (CDA) and incubated at 25 ± 2°C with a 12-h photoperiod for 3 to 6 days. Morphology of the 78 isolates was examined; colonies were initially white, then turned light to dark brown and greyish black and produced abundant aerial hyphae. Conidiop...

Production of watermelon (Citrullus lanatus) in Malaysia was 150,000 mt in 2020 (Malaysian Department of Agriculture, 2021). In November 2019, nine locally produced watermelon fruit (red flesh, seedless) from five local stores in the states of Kelantan, Terengganu, and Penang exhibited sunken, circular, brown lesions that enlarged to1.5 to 10 cm in diameter with scattered orange masses of conidia. Lesions coalesced to cover approximately 50% of the fruit surface. Lesions were surface sterilized by spraying 70% alcohol onto the fruit followed by drying with sterilized paper towels. A total of 153 tissue segments (1×1 cm) were excised from the rind, immersed in 1% sodium hypochlorite for 3 min, rinsed twice for 1 min in sterilized distilled water, air-dried, transferred to potato dextrose agar (PDA) plates, and incubated at 25±1°C for 7 days. Single-spore transfers produced pure cultures, resulting in 12 isolates. Colonies on PDA were initially white and turned pale gray with age. Conidia were hyaline, one end round and the other narrowly acute, aseptate, smooth-walled, straight, cylindrical to clavate, 10.5-16.5 µm × 3-4.5 μm (n = 30). Observed morphological characters matched published description of Colletotrichum spp. (Damm et al. 2012). Internal transcribed spacer (ITS) and glyceraldehyde-phosphate dehydrogenase (GAPDH) genes were amplified using primer sets ITS1/ITS4 and GDF1/GDF2, respectively. All sequences were deposited in GenBank (MW856808 for ITS; MZ219296 for GAPDH). A BLASTn search of both sequences on GenBank showed 99% identity with C. scovillei along with other closely related Colletotrichum species. Phylogenetic analysis of ITS and GAPDH alignments, using maximum likelihood along with reference strains of closely related species from Mycobank, confirmed species identity as C. scovillei. A pathogenicity test was conducted on two healthy watermelon fruit (red flesh, seedless). A 6-mm-diameter mycelial plug of a colony on PDA was positioned on a 0.5-cm-long wound on each fruit; a sterile PDA plug placed on a similar wound on the opposite side served as a control. Fruit were incubated at 25±1°C for 7 days in plastic-wrapped trays above distilled water to maintain high humidity. Small, sunken, circular brown lesions appeared and expanded at inoculation sites within 7 days. Symptoms were identical to those produced by natural infections, and the controls were asymptomatic. Isolates from the lesions at the inoculation sites were confirmed as C. scovillei based on morphological characteristics, fulfilling Koch's postulates. The pathogenicity test was conducted four times with a total of eight fruit. Many species in the C. orbiculare complex cause watermelon anthracnose (Keinath, 2018). To our knowledge, this is the first report of C. scovillei (C. acutatum species complex; Damm et al. 2012) causing anthracnose on watermelon in Malaysia. Anthracnose caused by C. scovillei has been confirmed on other crops such as pepper (Toporek and Keinath, 2021), banana (Zhou et al., 2017), and chili (Oo et al., 2017). This insight will inform efforts to improve management of watermelon anthracnose in Malaysia.