Postharvest Fruit Rot Research Articles

First Report of Alternaria alternata Causing Postharvest Fruit Rot of Jujube in Pakistan

First Report of <i>Alternaria alternata</i> Causing Postharvest Fruit Rot of Jujube in Pakistan

First Report of Two Penicillium spp. Causing Postharvest Fruit Rot of Grapes in Pakistan

First Report of Two <i>Penicillium</i> spp. Causing Postharvest Fruit Rot of Grapes in Pakistan

First Report of Postharvest Rot Caused by Pestalotiopsis sp. on Grapes in Punjab, Pakistan

Grapes (Vitis vinifera L.), a major crop in Pakistan, are cultivated mostly for the fresh market. In June 2016, severe fruit rot was observed in packing houses in Rawalpindi (33°38′19.2″N, 73°01′45.0″E) and Chakwal (32°56′01.5″N, 72°50′37.1″E) districts of Punjab province on cvs. King’s Ruby and Perlette after 3 to 5 days of postharvest storage. To determine incidence of symptoms, 10 boxes of each grape variety were selected randomly from each of five packing houses per district. Disease incidence was recorded at 4 to 6%. Initial symptoms occurred mainly on wounded berries; following infection, the fruit skin turned reddish brown, after which the area of discolored skin increased and whitish mycelium developed on the lesions. A total of 400 symptomatic berries were surface sterilized by immersing cheese cloth bags containing detached berries in 1% sodium hypochlorite for 1 min, then rinsing three times with sterile distilled water and allowing the berries to dry by placing them on filter paper for 45 s. Surface sterilized tissues at the margins of lesions were excised into 4-mm³ segments and then transferred to potato dextrose agar (PDA) and incubated at 25 ± 2°C. After 1 week, fungal colonies were white, floccose, and cottony, with black acervuli forming distinct concentric rings. A total of 29 isolates were examined morphologically; conidia were fusiform, straight or slightly curved, 4 to 5 celled, and 19.7 to 30.2 × 4.8 to 6.2 μm. The color of conidia was dark umber to olivaceous with a darker band at the septum between cells. Two to three appendages (22.6 ± 0.6 μm long) appeared at the apex of each conidium; apical appendages were not knobbed, whereas the basal end had a single appendage with a knobbed tip that was 5.7 ± 0.4 μm long. According to colony and conidia morphology, the isolates were identified as Pestalotiopsis clavispora (G.F. Atk.) Steyaert (Gonzalez et al. 2012; Guba 1961). The internal transcribed spacer (ITS1, 5.8s, and ITS2) region of isolates PSTL01, PSTL06, and PSTL12 was amplified using ITS1 and ITS4 primers. Sequence comparison revealed 99% genetic homology (accession nos. MF448223, MF571908, and MF571909) with previously reported isolates of P. clavispora (KY319134 and KM402033). To confirm pathogenicity, 10-µl aliquots of conidial suspension (10⁶ spores/ml) of PSTL01, PSTL06, or PSTL12 were pipetted onto three nonwounded and four wounded asymptomatic grape berries of cv. King’s Ruby per isolate; sterile distilled water was used as a negative control. The berries were incubated at 25 ± 2°C in sterile moist chambers, and the experiment was conducted twice. After 3 days, whitish mycelium and sunken lesions, similar in appearance to the original lesions, developed on both wounded and nonwounded inoculated berries, whereas no symptoms appeared on the negative controls. The morphology of the fungus that was reisolated on PDA was identical to that of the original cultures. Pestalotiopsis sp. has been reported to cause postharvest fruit rot on grapes in Korea (Deng et al. 2013). To our knowledge, this is the first report of Pestalotiopsis sp. causing fruit rot of grapes in Pakistan, where the disease poses a significant threat to sustainability of grape producers.

First Report of Postharvest Fruit Rot of Tomato (Lycopersicum esculentum Mill.) Caused by Penicillium olsonii in Pakistan

A previously unnoticed fruit rot of tomato was observed during a survey in 2016 in the nursery of the University of Punjab, Lahore, Pakistan. Disease incidence was recorded at 9%. The symptoms were initially characterized as small water-soaked lesions on the epidermis that expanded and developed into watery rot. Isolations from symptomatic skin and tissue of the pericarp yielded species of Penicillium. A representative isolate of Penicillium was identified on the basis of morphological characteristics and by sequencing the internal transcribed spacer region of DNA and partial sequencing of the β-tubulin gene using ITS1 and ITS4 (White et al. 1990) and Bt2a and Bt2b (Glass and Donaldson 1995) primers, respectively. The associated fungus was identified as Penicillium olsonii. The colony of P. olsonii reached a diameter of 80 mm after 7 days of incubation at 25 ± 2°C on potato dextrose agar. The colony appeared white earlier in growth and then became dull green with conidiogenesis. The reverse side of the colony was pale yellow to cream yellow. The colony texture was velvety, occasionally with clear exudates and no pigmentation. The mycelium was white. Conidiophores were unbranched, smooth walled, and measured 650 to 800 × 4.5 to 6.5 µm. The phialides were flask shaped with a short neck and measured 8 to 10 × 2.5 to 3 µm (n = 50). The conidiophores had terminal terverticillate appressed penicillia. The conidia were subglobose to ellipsoidal with granular wall and measured 3.5 to 4 × 2.5 to 3.5 µm. The morphological characteristics were consistent with P. olsonii based on the description by Pitt (1979). The ITS1 region (GenBank accession no. LT900496) of 565 bp showed 100% homology with P. olsonii isolates (KY859385.1, JQ663620.1, DQ117963.1, and AY373925.1) from the NCBI database. The partial β-tubulin gene (accession no. LT900495) of 456 bp showed 100% identity with P. olsonii isolates (KR709179.1, AY674444.1, KU507286.1, and DQ645787.1) from GenBank. Pathogenicity of the fungus was demonstrated on tomato fruit according to Koch’s postulates. Healthy detached fruits of tomato were surface disinfested and stab inoculation was conducted using a needle rubbed over a 5-day-old culture of P. olsonii. A total of 20 control fruits were inoculated with a needle without inoculum and a total of 20 fruits were inoculated with P. olsonii and kept in a plastic bag at 25 ± 2°C for 20 days. Each fruit was inoculated at three points. Black spots appeared on inoculated tomato fruits after 10 days, which expanded to form larger gray-black lesions with evidence of mycelial growth in the center after 10 to 15 days of incubation. On the basis of mycological, molecular, and pathologic characteristics, the fungus reisolated from the fruits was identified as P. olsonii. P. olsonii has been reported previously to cause blue mold on tomato (Chatterton et al. 2012). This study appears to be the first report of postharvest fruit rot on tomato caused by P. olsonii in Pakistan. The occurrence of P. olsonii on other crop plants and its wide host range together suggest potential for this fungus to be a pathogen on a range of plant genera/species.

First Report of Coniella granati Fruit Rot and Dieback on Pomegranate in the Western Cape of South Africa

Shoot dieback and necrotic black lesions were observed on pomegranate trees (Punica granatum Linn.) in commercial orchards in South Africa near Ladismith and Malmesbury in 2011. Postharvest fruit rot was identified from an orchard near Malmesbury in 2011. Affected fruit decayed after two months storage (5 – 7 C) and were covered with globose brown pycnidia (mean length x width: 113 x 102 μm; diameter range 72 – 149 μm; 40 spores). Fungal cultures isolated from fruit and shoot symptoms were morphologically identified as Coniella granati Sacc. Petrak and Sydow (synonym Pilidiella granati Saccardo; Alvarez et al., 2016). Hyphae were septate with hyaline, one-celled, ellipsoid to fusiform conidia (10.15 to 14.39 x 2.67 to 4.42; average of 20 spores: 11.35 × 3.28 μm). Sequence data of the translation elongation factor alpha gene (TEF1, MG255164), and internal transcribed spacer region (ITS1-5.8S-ITS2; Genbank Accession No. KU666470, KU666471) confirmed identifications with 99-100% similarity to reference sequ...

Isolation and identification of pathogenic fungi causing postharvest fruit rot of kiwifruit (Actinidia chinensis) in China

AbstractKiwifruit is a very important commercial crop in China, which is the largest producer of the fruit in the world. The rapid expansion of areas of kiwifruit cultivation has resulted in the spread of postharvest rot diseases. To clarify the pathogens causing kiwifruit postharvest rots in China, 76 pure strains were isolated from 138 rotten fruits during the shelf‐life period, with fruit collected from the 11 main regions of kiwifruit cultivation (Shaanxi, Sichuan, Henan, Guizhou, Hubei, Anhui, Jiangxi, Hunan, Fujian, Zhejiang and Jiangsu provinces) during 2014–2015. By examining the morphological and microscopic characteristics together with the results of pathogenicity testing and ITS (internal transcribed spacer) sequencing, four species were identified as the main pathogens causing kiwifruit postharvest rots in China. They were Phomopsis sp., Botryosphaeria dothidea, Alternaria alternata and Pestalotiopsis microspora, with identification rates of 52.6%, 23.7%, 13.2% and 10.5%, respectively. All isolates inoculated on wounded fruit were pathogenic but non‐pathogenic when peels were unwounded except B. dothidea. These findings have important implications for resistance breeding and control of kiwifruit postharvest rots in China.

Incidence Rates of Major Diseases of Kiwiberry in 2015 and 2016.

Incidence rates of diseases in kiwiberry orchards were investigated monthly from late June to late September in Gwangyang and Boseong in 2015 and 2016. The impact of postharvest fruit rot was investigated during ripening after harvest. Bacterial canker was only observed on one single tree in 2015, but black rot, powdery mildew, leaf spot and blight, and postharvest fruit rot diseases were problematic throughout the study period in both 2015 and 2016. Incidence rates of the diseases varied with kiwiberry cultivar, region and sampling time. Incidence rates of powdery mildew, leaf spot and blight diseases increased significantly during the late growing stages near fruit harvest, while black rot peaked in late August. Incidence rate of postharvest fruit rot on fruit without fruit stalks was less than half of fruit with fruit stalks, regardless of kiwiberry cultivars. Among the four cultivars, Mansu was relatively resistant to black rot and postharvest fruit rot diseases. In our knowledge, this is the first report of various potential pathogens of kiwiberry in Korea.

First Report of Postharvest Fruit Rot Caused by Fusarium equiseti on Stored Cerasus pseudocerasus in China

First Report of Postharvest Fruit Rot Caused by <i>Fusarium equiseti</i> on Stored <i>Cerasus pseudocerasus</i> in China

First Report of Alternaria alternata Causing Postharvest Fruit Rot of Lychee in Pakistan

Jujube (Ziziphus mauritiana Lamk), commonly known as “ber,” is a minor fruit in Pakistan that is cultivated on an area of 5.129 ha. In January 2017, severe fruit rot disease was observed in several markets located in the Faisalabad (31°25′15.7620″N, 73°5′21.4584″E) district of Punjab-Pakistan, with disease incidence ranging from 15 to 26%. Initially, small, oval, light to dark brown lesions (1 to 3 mm) were observed on the fruit surface, which gradually enlarged in size and led to total fruit rot. To isolate the pathogen, small tissue segments were cut from rotted fruit, surface disinfected with 1% NaClO for 2 min, rinsed three times in sterilized distilled water, air dried, and then placed aseptically onto potato dextrose agar (PDA) medium. Tissue samples were cultured at 25°C under a 12-h light/dark photoperiod for 3 days. Isolates were transferred to fresh PDA medium and cultured for 7 days. The cultured isolates consistently yielded dark brown to black colonies (85% isolation rate from 40 fruit tissues). Conidiophores were short, septate, 20 to 52 μm long, and 1 to 3 μm wide. Conidia were in chains (average conidial dimension 20 to 28 × 8 to 10 μm), brown and ovoid, with a short conical beak with both transversal (two to five) and longitudinal (one to three) septa. Based on morphology, the pathogen was identified as Alternaria alternata (Simmons 2007). To confirm the identification, genomic DNA was extracted and amplified using ITS1/ITS4 primers (White et al. 1990) and endopolygalacturonase gene using primers PG3/PG2b (Andrew et al. 2009). The resulting sequences were deposited in GenBank (accession nos. KY859867 and MF371420). BLAST analysis showed 99 to 100% homology to A. alternata sequences KJ957793 and AY295025 isolated from Korea and the United States, respectively. Pathogenicity tests were conducted on 20 surface-sterilized jujube fruit (cultivar Dilbhar) by spraying them with a conidial suspension (10⁶ conidia/ml) using a handheld sprayer. Ten fruit inoculated with sterile water served as a non-treated control. Fruit samples were kept in a moist chamber at 25°C and 70 to 80% relative humidity with a 12-h photoperiod. After 2 to 3 days of inoculation, all fruit displayed small, light to dark brown lesions followed by rotting. Reisolations from symptomatic fruit consistently yielded a fungus identical to A. alternata. Control fruit remained disease-free. Fruit rot of jujube caused by A. alternata has been reported in India and China (Wadia and Manoharachary 1980; Wang et al. 2009). To our knowledge, this is the first report of A. alternata causing postharvest fruit rot of jujube in Pakistan. The disease could represent a threat to jujube cultivation.

Postharvest Diseases and Effect of Hot Water Treatments on White Fleshed Dragon Fruit [Hylocereus undatus (Haw.) Britton &amp; Rose

Postharvest rots are a significant limitation to the storage life of white fleshed dragon fruit, this paper aimed to identify the main pathogens associated with postharvest diseases in the Mekong delta region, to identify the origins of infections, and to investigate the use of heat treatments for postharvest rot control. Dragon fruit were stored at 0°C, 5°C and 10°C for 26 days followed by 3 days shelf life at 20°C. Other fruit were held at 20°C for 7 days as a non-stored control. The main fungi associated with postharvest rots were Alternaria alternata, Bipolaris cactivora, Colletotrichum truncatum, Fusarium dimerum, Fusarium equiseti and Rhizopus stolonifer. Skin pieces plated out from freshly harvested surface sterilised fruit yielded C. truncatum, F. dimerum, F. equiseti, A. alternata, and B. cactivora. Surface swabs from fruit in the field yielded A. alternata and Fusarium sp. The study showed that, except for those caused by R. stolonifer, all postharvest rots of dragon fruit have their origin either as latent infections in the field or as surface-borne spores. Many of the rot pathogens could grow at low temperatures and surface-borne Fusarium and Alternaria species were able to infect the fruit during storage. To test the effect of hot water treatments (HWTs) on postharvest rots, freshly harvested fruit were immersed at 49, 51, 53, and 55°C for two or three minutes, stored at 5-6°C for 28 days and 3 days shelf life. HWTs at 49°C and 51°C for two or three minutes both completely inhibited rots during storage, and after the shelf-life, significantly fewer rots were observed than other HWTs and the untreated control. The 49 and 51°C HWTs also showed the least weight loss no damage to bracts, and no effect on titratable acidity, total soluble solids, fruit firmness, or flesh or skin colour. Current gaps in knowledge of postharvest rots and research strategies to address them are outlined in the paper.

First Report of Cytospora punicae Causing Post-Harvest Fruit Rot on Pomegranate in South Africa

First Report of <i>Cytospora punicae</i> Causing Post-Harvest Fruit Rot on Pomegranate in South Africa

Influence of boron applications on preharvest and postharvest nectarine fruit rot caused by brown rot

Brown rot is a very important disease of stone fruit causing mainly postharvest damages on fruit, although preharvest fruit rots and shoot blight are also important. With recent public concerns regarding pesticide residues on fruit, there is a need for alternative disease management practices that will reduce health risks resulting from occupational exposure and from residues in food and drinking water. The main aim of this study was the investigation of the effects of boron on the susceptibility of nectarine (cv Tasty Free) on preharvest and postharvest fruit rots. The results demonstrated the fungicidal activity of organic chemical structure of boron to the mycelial growth of M. laxa in vitro. This product inhibited the mycelial growth and conidia germination of M. laxa at concentration of 1000 and 1600 μl/l respectively. The EC 50 value was 690.9 μl/l for the mycelial growth and 985 μl/l for the conidia germination respectively. Spray applications of nectarine trees reduced the susceptibility of fruit on preharvest and postharvest fruit rots caused by brown rot. Generally, boron application is an effective, alternative method to improve the resistance of nectarine to brown rot.

Occurrence of a Postharvest Fruit Rot Disease of Apples Caused by Boeremia exigua var. exigua in Ptolemaida Kozani, Greece

Occurrence of a Postharvest Fruit Rot Disease of Apples Caused by <i>Boeremia exigua</i> var. <i>exigua</i> in Ptolemaida Kozani, Greece

First Report of Lasiodiplodia pseudotheobromae Causing Postharvest Fruit Rot of Lemon in Turkey

First Report of <i>Lasiodiplodia pseudotheobromae</i> Causing Postharvest Fruit Rot of Lemon in Turkey

Efficacy of garlic extract and yeast against Penicillium digitatum causing post harvest fruit rot of citrus (Citrus sisnensis L.)

Freshly prepared 1 per cent garlic extract and 5 per cent yeast solution were tested against Penicillium digitatum causing fruit rot (green mold ) of sweet orange both under in vitro and in vivo . 1 per cent garlic extract gives 15.7 per cent control and 5 per cent yeast gives 15 per cent control against Penicillium digitatum . Artificially inoculated fruits treated with 1 per cent G. E. were observed in good condition upto 35 days and 5 per cent yeast treated citrus fruits upto 45 days. Use of garlic extract and yeast maintains the quality of citrus fruits, prolonged the shelf-life and delayed the rottenness presence on fruits. Penicillium digitatum could grow between temperature ranges of 20°C to 45°C, however, optimum temperature was 27 ± 1°C at which growth and sporulation of the fungus was maximum.

First Report of Penicillium biourgeianum causing Post-Harvest Fruit Rot of Apple in Pakistan

First Report of <i>Penicillium biourgeianum</i> causing Post-Harvest Fruit Rot of Apple in Pakistan

FIRST REPORT OF PILIDIELLA GRANATI CAUSING POSTHARVEST FRUIT ROT ON POMEGRANATE IN SOUTHERN ITALY

In 2015, rot symptoms were observed during storage on pomegranate fruit (Punica granatum L.) cvs Wonderful and Mollar de Elche from a packinghouse in Apulia (Southern Italy). Symptoms, observed on 26% of fruit, consisted of circular brownish-yellow lesions, beginning in the crown area and quickly expanding to entire fruit, with softening of the tissues including arils. Tissue portions were cut from surface-sterilized fruit and incubated on semi-selective PDA at 28±1°C in the dark. Colonies were white to creamy, leathery, and covered by abundant dark-greenish- brown to black spherical pycnidia (80-140 μm in diameter) with thin membranous walls. Hyphae were septate, and conidia hyaline, one-celled, 10-17.5×2-5 μm, ellipsoid to fusiform, straight or slightly curved. These characteristics corresponded to Pilidiella granati (Saccardo) (syn. Coniella granati Sacc.) Petr. & Syd.). For molecular confirmation, fungal DNA was amplified using universal primers ITS5/ITS4. BLAST analysis of the 506 bp amplicon (GenBank accession No. KU821701) showed 100% identity with other P. granati ITS sequences. For pathogenicity tests, surface-sterilized fruit of both cvs were wounded (5×5 mm), inoculated by a mycelial plug and incubated as reported above. Sterile plugs were used as controls. Lesions were visible after five days only on inoculated fruit. The re-isolated fungus corresponded to P. granati, which was reported as pomegranate postharvest rot agent in Spain (Palou et al., 2010) and recently associated with a crown rot in Italy (Pollastro et al., 2016). To our knowledge, this is the first report of P. granati rot on harvested pomegranate fruit in Southern Italy that might represent a serious threat for marketing of this promising crop.

First report of Aspergillus sp. causing postharvest fruit rot in cambuci (Campomanesia phaea) in Brazil

Cambuci (Campomanesia phaea), family Myrtaceae, is one of the most important endemic fruits of the Atlantic forest. In Brazil, the fruit is processed and consumed as jam, juice and ice cream. In October 2015, unusual fruit rot symptoms were observed five-ten days after harvest on cambuci kept at room temperature in packing houses in Salesópolis and Piracicaba, São Paulo State. Disease symptoms were soft lesions on the fruit surface with abundant dark grey mycelium and sporulation, and losses of up to 70% were observed. The pathogen was isolated on potato dextrose agar by sampling spores from the lesions. A representative monosporic isolate, CAM1USP was identified on the basis of morphological and molecular (rDNA-ITS) features. This isolate was stored in the mycological collection of the Laboratory of Epidemiology, University of São Paulo. When the isolate was incubated in the dark at 25°C for seven days, the colonies initially developed white mycelium without zonation and later were covered with a dense layer of dark brown or black radiate conidial heads (Fig. 1). Vesicles were subglobose to globose and measured 43.8 to 55.1 μm (n = 50). Conidia produced in vitro were brown to black, subglobose to globose and measured in diameter (4.7-) 5.6 (-6.4) μm (n = 50). All morphological features were similar to those of Aspergillus section Nigri (Varga et al., 2). To identify the species, DNA was extracted using a Promega Wizard genomic DNA purification kit (Madison, USA). Primer pairs ITS1 and ITS4 (White et al., 3) were used to amplify the ITS1-5.8S-ITS2 region. The resulting sequence of 523 bp (GenBank Accession No. KU751784) was compared to other sequences and was most similar to A. aculeatus (KP965728, 93%), A. japonicus (KP193133, 93%) and A. niger (KT726919, 92%). To test pathogenicity, ten cambuci fruits were disinfected with 0.5% sodium hypochlorite solution for one minute, wounded (3 mm deep) with a sterile histological needle and wound-inoculated with a 50 μl conidial suspension (106 conidia/ml). Ten control fruits were inoculated with sterile water. Fruits were maintained in a moisture chamber for 24 hours and kept at 25°C on the laboratory bench for one week. Two days after inoculation, all Aspergillus-inoculated fruits showed soft lesions that increased quickly in diameter, with abundant dark grey mycelium (Fig. 2). Aspergillus sp. was re-isolated from the lesions fulfilling Koch's postulates. Molecular and morphological characterisation and pathogenicity tests were repeated twice. The genus Aspergillus is known to cause postharvest diseases in fruit and seeds and toproduce mycotoxins in different crops (Palencia et al., 1). To our knowledge, this is the first report of Aspergillus sp. associated with postharvest fruit rot in cambuci and further studies will be necessary to fully resolve the taxonomy.

Neopestalotiopsis vitis sp. nov. causing grapevine leaf spot in China

Neopestalotiopsis species are associated with a post harvest fruit rot and trunk disease of grapevines in China. A new species, N. vitis was isolated from the grape leaf spot in Guangxi Province, China. Initially, small circular, slightly sunken, necrotic spots, developed on the leaf surface, mainly at the inter-vein regions. The spots enlarged rapidly turning irregular, necrotic and brittle with age. Phylogenetic species recognition based on analysis of the combined ITS, TUB2 and tef1 sequence data coupled with morphology distinguished N. vitis from all other known species in the genus. This is the first report of a Neopestalotiopsis species causing a leaf spot on grapevine.

First Report of Post-Harvest Fruit Rot of Aronia melanocarpa Caused by Fusarium tricinctum in Korea

First Report of Post-Harvest Fruit Rot of Aronia melanocarpa Caused by Fusarium tricinctum in Korea