Blotter Method Research Articles

Morpho-molecular characterization of fungi associated with seeds of hybrid rice varieties in bangladesh

Rice, as the dominant crop in Bangladesh, is vulnerable to various fungal pathogens. Many of these pathogens infect the seeds, which can later transmit diseases and serve as an efficient means for spreading seed-borne pathogens over long distances. In this study, seven hybrid rice varieties, specifically BRRI Hybrid Dhan 101 through BRRI Hybrid Dhan 107, were collected from the Bangladesh Rice Research Institute (BRRI) to detect and identify seed-borne fungi using both morphological and molecular techniques. Fourteen fungal species were isolated from the selected rice varieties using “Tissue planting method” and “Blotter method”, of which 4 fungal isolates were identified by molecular techniques. Molecular characterization of the isolates was conducted based on the sequence information of internal transcribed spacer (ITS) regions. The sequences obtained using the ITS1 and ITS4 primers were compared with those in the NCBI GenBank using BLAST analysis. Hybrid rice is comparatively more advantageous than inbreed rice because of its high yield, shorter plant life, and higher assimilation translocation. Therefore, it is crucial to identify and manage the pathogenic fungi associated with the seeds to ensure good seed quality, which can contribute to improving the economy of Bangladesh. Bangladesh J. Bot. 53(3): 511-518, 2024 (September)

Morphological and molecular identification of fungi isolated from selected brri rice varieties

A total of 19 fungal species were isolated from the seeds of selected rice varieties (BRRI dhan 90 to BRRI dhan 99) following Tissue planting method and Blotter method. The isolated fungi were Aspergillus niger, A. ochraceus, A. oryzae, A. tamarii, A. terreus, Chaetomium globosum, Cladosporium oxysporum, Colletotrichum gloeosporioides, Corynespora cassiicola, Curvularia lunata, Curvularia soli, Daldinia eschscholtzii, Fusarium solani, Penicillium oxalicum,Penicillium sclerotiorum, Pestalotiopsis guepinii, Pyricularia oryzae and Rhizopus stolonifer. Fourteen fungi were selected for molecular identification. Out of the 19 fungal isolates, 14 were confirmed up to species level through ITS sequence based molecular analysis. Among the isolated fungi Pnicillium sclerotiorum and Curvularia soli are the new record for Bangladesh. Association of Daldinia eschscholtzii with rice seeds is also recorded first time from world. Bangladesh J. Plant Taxon. 31(1): 73-82, 2024 (June)

Fungicide evaluation against head smudge (Curvularia spp.) and its impact on yield and germination of tef (Eragrostis tef Zucc.)

Head smudge, caused by Curvularia spp., is the major disease of tef in the humid tef-growing areas of Ethiopia. Despite this, farmers continue producing tef without any disease management strategies, which is leading to substantial quantitative and qualitative losses. Hence, the field and laboratory experiments were conducted to assess the efficacy of seven fungicides for the management of head smudge and simultaneously to assess the possible effects of the disease on seed quality of tef. The field experiment was conducted at Dangila and North Achefer districts and the treatments were arranged in a randomized complete block design with three replications. Tef seeds harvested from field experiments were subsequently used for laboratory studies using the blotter method and arranged in a completely randomized design. The effect of fungicides on reducing disease incidence and severity and increasing yield was significant (p < 0.001). The highest overall mean disease control (88.9%) was obtained from propiconazole sprayed plots followed by trifloxystrobin + tebuconazole and tebuconazole, both of which had a similar 85.5% disease reduction. The applications of triadimefon resulted in intermediate disease reduction (69.9%). However, the application of mancozeb + cymoxanil, cymoxanil + copper oxychloride, and thiamethoxam + metalaxyl + difenoconazole doesn’t bring a significant improvement from the untreated plot. According to our findings, head smudge can reduce tef yield by up to 62% and germination by 18.7 to 45.4%. Therefore, the application of propiconazole, trifloxystrobin + tebuconazole, and tebuconazole can be considered as effective head smudge management practice until other management options are developed.

Studies on Association of Seed Borne Mycoflora in Different Varieties of Black Gram [Vigna mungo (L.) Hepper] by Incubation Methods

The present study was conducted to detect and identify seed-borne pathogenic fungi in some different varieties of black gram and their effect on seed germination. Six varieties of black gram (Indira urd-1, Pratap-1, KU-96, TPU-4, TIU-22) and local variety collected from village for experiment. The Eleven seed associated mycoflora recorded were Aspergillus flavus Aspergillus niger, Fusarium spp., Alternaria spp., Rhizopus spp., Penicillium spp., Curvularia spp., Cladosporium spp., Colletotrichum spp., Chaetomium spp. and Trichoderma spp. were detected and identified from the seeds of different varieties of black gram by using the standard blotter method, agar plate method, 2,4-D blotter method, roll paper towel method and deep freeze method. In all these methods, poor germination percentage was recorded in local variety, may be due to the presence of seed associated mycoflora with maximum frequency, whereas KU-96 variety has most extreme germination percentage due to the minimum frequency of seed associated mycoflora as compared to other varieties of black gram taken in the examination.

Radicle Stage Heat Stress Mitigation through Spermidine Seed Priming in Rice

High temperature has adverse effects on rice seed seedling establishment. Priming is one of the easiest methods to alleviate heat stress. Spermidine is a polyamine that effectively reduces several abiotic stresses, including heat stress. A study was conducted for the spermidine seed priming to alleviate heat stress during the radicle stage of rice. The seeds were primed with three different concentrations of spermidine (0.5 mM, 1 mM and 1.5 mM), using three different methods of imbibition (direct soaking, blotter method, polyethylene glycol (PEG) method) before subjecting them to heat stress at the radicle stage. Results showed enhanced survival percentage with 1 mM spermidine priming in all the three methods of imbibition. In conclusion, seed priming with 1 mM spermidine concentration can effectively alleviate the adverse consequences of high temperature at the radicle stage and help in the development of normal seedlings.

Prevalence of seed-borne Fusarium in local rice cultivars from Barishal district

Seed-borne diseases cause substantial yield loss of rice every year. The present study was conducted to determine the status of seed-borne Fusarium spp. infection in farmers’ saved rice seeds of nine local cultivars collected from all ten upazila of Barishal district. Two fungal species of Fusarium, i.e., Fusarium fujikuroi, and Fusarium equiseti were identified based on morphological characteristics using the blotter method. The highest infection of F. fujikuroi was observed in Babuganj upazila (11.11%), followed by Agailjhara (8.83%). On the other hand, the highest infection of F. equiseti was observed in Bakerganj (8.17%), followed by Mehendiganj (8.05%). The lowest infection of F. fujikuroi and F. equiseti was observed in Muladi, with values of 5.22% and 4.54%, respectively. Among local cultivars, the highest infection of F. fujikuroi (7.11%) was observed in Lalpaika followed by Sakkhorkora (6.83%). On the other hand, the highest infection of F. equiseti was observed in Dudhmona (9.17%) followed by Kajalshail (8.94%). The lowest infection of F. fujikuroi and F. equiseti was observed in the Bhushihara cultivar with the same infestion (4.61%). The prevalence of Fusarium spp. varied with respect to the location of seed collection as well as cultivars. Highest seed germination was observed in Bhushihara (89%) followed by Swarna (87%) and Joyna (85%). Lowest seed germination was observed in Lalpaika (78%). The highest mortality of the seedlings after germination was observed in Lalpaika (24.25%), followed by Dudhmona (23%) and the lowest mortality of the seedlings was observed in Bhushihara (14.75%). Thus, seed germination rate and post-emergence mortality of seedlings were directly associated with seed-borne infection of F. fujikuroi and F. equiseti. Ann. Bangladesh Agric. (2023) 27 (2): 31-39

Incidence and management of wheat seed borne fungi collected from Baghlan Province, Afghanistan

To identify the association of seed borne fungi in wheat seed samples (20 wheat genotypes collected from 11 different districts of Baghlan province), the standard blotter method was used. Thirteen seed borne fungi, viz. Alternaria alternata, Bipolaris spp, Gibberella zeae, Curvularia lunata, Rhizopus stolonifer, Aspergillus flavus, A. niger, Penicillium spp, Cladosporium cladosporioides, Acremonium spp, Ulocladium spp, Arthrobotrys oligospora and Tilletia indica were observed from the seeds. Nine wheat varieties collected from Zonal Agricultural Research Station, Baghlan, Afghanistan were analyzed for the association of seed borne fungi. Ten fungi, viz. A. alternata, Acremonium spp, Cladosporium cladosporioides, Ulocladium spp, Curvularia lunata, Bipolaris spp, Gibberella zeae, A. flavus, A. niger and Penicillium spp. were recorded. Among them A. alternata and Bipolaris spp. were predominant in most of the seed samples. Minimum per cent infection of 1.33% was recorded with treatment having Ridomil @2.5 g/kg seed whereas maximum seeds infection of 52% was recoded in control. Present study revealed the occurrence of seed borne fungi in different wheat genotypes in Baghlan province of Afghanistan. Studies helped in identifying suitable fungicides and bioagents for managing seed borne fungi in wheat.

Identification on seed associated mycoflora of sesame genotypes

Seed mycoflora of 165 genotypes of sesame in (AVTs &amp; IVTs) were detected using seed health testing methods viz., paper towel method, standard blotter method, and standard agar plate method and six distinct fungi viz.,Alternaria, Macrophomina, Fusarium, Aspergillus, Penicillium, and Rhizopus spp. were detected. In the three methods employed to identify seed mycoflora the standard blotter method has identified the maximum number of seeds infected by fungi compared to paper towel method and standard agar plate method. After a few days of germination, it was observed that the majority of the seeds were infected with disease, which hampered normal seedling growth and resulted in abnormal and rotted seedlings.

Studies on Seed Borne Mycoflora of Soybean Seeds by Incubation Methods

The present study was conducted to detect and identify seed-borne pathogenic fungi in some soybean varieties and their effect on seed germination. Six varieties of soybean seed samples viz.JS 95-60, JS 97-52, RSC 10-46, RSC 10-71, CG Soya-1 and local variety were selected for the experiment. Twelve seed-borne mycoflora viz. Aspergillus flavus, Aspergillus niger, Alternaria spp., Cladosporium spp., Curvularia spp., Rhizopus spp., Trichoderma spp., Rhizoctonia spp., Nigrospora spp., Macrophomina spp., Fusarium spp. and Penicillium spp. were detected and identified from the seeds of six soybean varieties by using the standard blotter method, agar plate method, 2,4-D blotter method, roll paper towel method and deep freeze method. The seed sample of local variety recorded the highest percentage of mycoflora with the lowest germination percentage, whereas CG Soya-1 variety found as the least percentage of mycoflora with the highest germination percentage compared to other varieties of soybean taken in the study. Among all of the incubation methods, the agar plate was found as the most effective in detecting seed-related mycoflora, on soybean seeds.

Seed Borne Fungal Pathogens Associated with Finger Millet Accessions

Seed health testing to detect seed-borne pathogens is an important step in the management of crop diseases. A study on the detection and identification of seed-borne fungi was done using seeds of finger millet (Eleusine coracana (L.) Gaetrn) accessions collected from different parts of the country. The research was undertaken to determine different seed-borne fungal pathogens associated with seeds of finger millet accessions from November 27, 2020 to February 25, 2021 at National Agriculture Genetic Resources Centre, Khumaltar, Lalitpur. A total of 85 seed samples, collected from different parts of the country, were used for the research. A hundred seeds of each sample were tested for the presence of seed-borne fungi using the Deep Freeze Blotter method following the International Rules for Seed Testing Association, 2001, and identification was done based on the growth habit, and morphology of the spores observed. One or more pathogens were detected in 65 out of 85 samples. Four different pathogens, namely Bipolaris nodulosa, Alternaria spp., Cladosporium spp., and Pyricularia grisea were identified. B. nodulosa and Cladosporium spp. were predominant in most of the samples with seed infection in 42 (49.4%) and 40 (47.05%) seed accessions, respectively. Hence, it is highly recommended to undertake focused research on the economic significance of the seed-borne fungi, while considering their impact and effective management strategies in order to enhance seed health management.

Comparative Study on the Seed Health of Five Commonly Cultivated Wheat Varieties (Triticum aestivum L.) in Nepal

Seed-borne pathogens can negatively affect wheat crop germination, plant health, and yield, making it essential to routinely test and treat seeds. Therefore, identifying seed-borne pathogens in commonly cultivated wheat varieties is vital to ensuring sustainable food production. The study sought at the Central Agriculture Laboratory in Lalitpur, Nepal, aimed to identify seed-borne pathogens in five commonly cultivated wheat varieties and evaluate their seed health. The study utilized the Standard Blotter Method to assess various parameters, including germination percentage, pathogen incidence percentage, shoot length, and seedling vigor index, in a controlled environment. The experiment used a complete randomized design with four replications and five treatments. Five wheat varieties (Gautam, Aaditya, Bijaya, Dhaulagiri, and NL971) were sown in Petri dishes containing blotting paper wetted with sterilized distilled water to assess the incidence and severity of Bipolaris sorokiniana. The data obtained were tabulated in Microsoft Excel and analyzed using Gen Stat. The study found that Gautam had the highest Bipolaris infection (18.25%), while NL971 had the lowest (11.25%), followed by Bijaya, Dhaulagiri, and Aaditya. Dhaulagiri had the highest germination percentage (99.50%), followed by Aaditya, Bijaya, and NL971, while Gautam had the lowest (79%). Aaditya demonstrated the highest shoot and root weight, shoot length, and seedling vigor index, while Gautam had the lowest. The study concluded that Gautam was vulnerable to low seed health, while Aaditya and other varieties demonstrated stronger seed health and resistance to the pathogen. These findings are crucial for improving seed health and ensuring sustainable food production in Nepal.

Deciphering of seed Health of common food grains (wheat, rice) of North Eastern UP and Gurgaon Haryana, India

The stored random samples of food seeds of wheat and rice (60 samples) were purchased from places of Eastern UP and Gurgaon district Haryana. Its moisture contents were estimated. The Mycological investigations of wheat seeds revealed presence of a total number of 16 fungal species viz., Alternaria alternata, Aspergillus candidus, Aspergillus flavus, A. niger, A. ochraceous, A. phoenicis, A. tamari, A. terreus, A. sydowi, Fusarium moniliforme, F. oxysporum F. solani, P. glabrum, Rhizopus nigricans, Trichoderma viride and Trichothecium roseum. While mycological analysis of rice seeds showed presence of 15 fungal species viz., Alternaria padwickii, A. oryzae, Curvularia lunata, Fusarium moniliforme, Aspergillus clavatus, A. flavus, A. niger, Cladosporium sp., Nigrospora oryzae, Alternaria tenuissima, Chaetomium globosum, F. solani, Microascus cirrosus, Helminthosporium oryzae, Pyricularia grisea. It also projected variation in presence of fungal species in blotter and agar plate method of analysis. In wheat Blotter method of analysis showed 16 fungal species while agar plate depicted 13 fungal species. In rice Agar plate method depicted presence of 15 fungal species while blotter method shows presence of 12 fungal species. The insect analysis revealed that wheat samples were infected with Tribolium castaneum. While rice seeds sample showed presence of insect Sitophilus oryzae. The investigations revealed that Aspergillus flavus, A. niger, Sitophilus oryzae and Tribolium castaneum caused reduction in seed weight loss, seed germination, carbohydrate and protein contents of common food grains (wheat, rice). It also revealed that randomly selected A. flavus isolate 1 of wheat showed higher potential of aflatoxin B1 production (1392.940 μg/l) while rice isolate 2 showed 1231.117 μg/l production.

Efficacy of Fungicides on Seed Mycoflora of Groundnut at Different Storage Periods

The present study was conducted at Seed Research &amp; Technology Centre, Professor Jayashankar Telangana State Agricultural University, Hyderabad, Telangana, India during January-June, 2016.The efficacy of 7 fungicides viz., captan (0.25%), mancozeb (0.25%), carboxin+thiram (0.3%), carbendazim (0.2%), benomyl (0.2%), tebuconazole (0.1%) and carbendazim+iprodione (0.2%) against seed mycoflora of groundnut at recommended dosages and at different storage periods (immediately after treatment, 1 day after treatment, 1 week after treatment, 2 weeks after treatment, 3 weeks after treatment, 1 month after treatment, 2 months after treatment and 3 months after treatment) were studied using standard blotter method. Treated seeds (of different storage periods) were incubated for 7 days and data on percent seed infection and frequency were recorded. Among the fungicides tested, seed treatment with carboxin+thiram (21.19%) was found significantly superior in reducing the percent seed infection followed by captan (24.00%) and the least effective was carbendazim (71.91%). A total of 13 seedborne fungi belonging to 10 genera viz., Macrophomina phaseolina, Rhizoctonia spp., Rhizopus spp., Aspergillus flavus, Aspergillus niger, Aspergillus ochraceus, Aspergillus ustus, Alternaria spp., Fusarium spp., Penicillium spp., Trichoderma spp., Chaetomium spp. and Cladosporium spp. were recovered from untreated and treated seeds at different storage periods. The percent seed infection by different seed mycoflora increased with the increase in storage period. However, there was a gradual decline in field mycoflora viz., Macrophomina phaseolina and Rhizoctonia spp. and gradual increase in storage mycoflora viz., Aspergillus spp., Cladosporium spp., Rhizopus spp., Penicillium spp. etc. found with the increase in storage period.

Fungi on bean seeds obtained from growers in Isparta province

The fungal load of seeds is among the factors related to seed quality. Seed-borne fungi can cause significant crop losses and may produce mycotoxins, which are harmful to human health. This study aimed to determine the seed-borne fungi of bean, which is among one of the most important crops cultivated in Isparta province. Seed samples from the 2015-2016 vegetation period, obtained from bean growers in Isparta province were used in this study. The fungal load of randomly selected 200 seeds were investigated by blotter and agar methods and prevalence and infestation rates of the fungi were determined. As a result, 41 species of fungi belonging to 26 genera were determined on 62 seed samples. The blotter method yielded 25 genera while 20 genera were determined by the agar method. Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium and Rhizopus species were the most common fungi found on almost all of the samples, for both methods. Infestation rates of these fungi were also high on bean seeds. Prevalence and infestation rates of the fungi were generally higher in the blotter method, except for Fusarium and Verticillium species that were determined on the seed samples in higher frequencies by the agar method. Absidia, Arthrinium, Epicoccum, Nigrospora, Scopulariopsis and Stachybotrys species were determined only by the blotter method, while Seimatosporium sp. was found by the agar method. Alternaria, Fusarium, Rhizoctonia, Stemphylium and Verticillium species are known as pathogenic fungi and may cause diseases on bean plants. Aspergillus and Penicillium species are saprobic fungi producing mycotoxins, so their presence on the seeds is also important.

First report of Diaporthe phaseolorum infecting Indian trumpet flower (Oroxylum indicum) from India

Seed health testing, using the blotter method, revealed some fungal growth on the seed surface of one accession of Indian trumpet flower/Broken bones tree (Oroxylum indicum (L.) Kurz) collected from Kokrajhar, Assam, India. The fungus was identified as Diaporthe phaseolorum (Cooke &amp; Ellis) Sacc. based on morphological characters. Later, the identity was re-confirmed by DNA sequencing using ITS gene sequencing (NCBI Sequence Id: MT154253.1) and a large subunit of rRNA (NCBI Sequence Id: OL798081.1). Literature reveals that D. phaseolorum is a destructive pathogen causing severe yield losses in various host crops. However, detection of D. phaseolorum in Indian trumpet flower seed followed by pathogenicity on its seedlings confirms that O. indicum is a new host record. Being a destructive pathogen of several other crops, such as seed decay and stem canker in soybean, it may pose a serious threat to future cultivation of this herbal plant.

Management of Seed Associated Fungi and Alternaria Leaf Spot Disease of Black Mustard (Brassica Nigra L.) Using Botanicals

The efficacy of five native botanicals viz., neem, castor, akondo, basok and ata against the seed associated fungi and in controlling the leaf spot disease of black mustard was evaluated. In blotter method, maximum reduction (85.91%) of seed associated fungi was observed in the seeds treated with ata (1:1) while neem (1:1), ata (1:2) and castor (1:1) gave 83.52, 82.59 and 82.39%, respectively reduction of fungi over control. Maximum seed germination (93%) was observed in seeds treated with akondo (1:1), where neem (1:1), castor (1:1) and akondo (1:2) supported 92, 92 and 90% seed germination, respectively. Maximum reduction of percent disease incidence (29.22%) and percent diseases severity (24.67%) were recorded with the application of neem (1:1) at 28 days after sowing with highest shoot length (16.09cm), root length (4.69cm), vigor index (1842.56%) and seed yield (33.70%) comparison to control in the net house. The findings neem (1:1) was found as an effective botanical for the ecofriendly management of seed associated fungi and Alternaria leaf spot diseases of black mustard.&#x0D; Bangladesh J. Agril. Res. 46(4): 407-416, December 2021

Marketed Quinoa (Chenopodium quinoa Willd.) Seeds: A Mycotoxin-Free Matrix Contaminated by Mycotoxigenic Fungi.

A total of 25 marketed quinoa seed samples different for origin, farming system and packaging were analyzed for the presence of mycotoxigenic fungi (by isolation both on Potato Dextrose Agar and with the deep-freezing blotter method) and relative contamination by mycotoxins (by LC-MS/MS analysis). Fungal microorganisms, but not mycotoxins, were detected in all the samples, and 25 isolates representative of the mycobiota were obtained. Morphological and molecular characterization and, for some isolates, the in vitro mycotoxigenic profile, allowed the identification of 19 fungal species within five different genera: Alternaria, Aspergillus, Penicillium, Cladosporium and Fusarium. Among the identified species, Alternaria abundans, A. chartarum, A. arborescens, Cladosporium allicinum, C. parasubtilissimum, C. pseudocladosporioides, C. uwebraunianum, Aspergillus jensenii, A. tubingensis, Penicillium dipodomyis, P. verrucosum and P. citreosulfuratum were first reported on quinoa, and Alternaria infectoria and Fusarium oxysporum were first reported on quinoa seeds. The geographical origin, farming system and packaging were showed to affect the amount and type of the isolated fungal species, highlighting that the level of fungal presence and their related secondary metabolites is conditioned by different steps of the quinoa supply chain. However, despite the presence of mycotoxigenic fungi, the marketed quinoa seeds analyzed resulted in being free from mycotoxins.

Prevalence and Management of Phytopathogenic Seed-Borne Fungi of Maize

Seed-borne fungi are solemn and deleterious pathogens capable of causing significant losses of quantity and quality losses in maize seeds and seedlings. They infect the crop at all points of the production chain from farms to stores. A yield loss of up to 50% can be encountered. Currently, chemical control of the disease is being implemented, though it is accompanied by several negative effects. This study aimed at identifying seed-borne fungi of maize and effective management options. A deep-freezing blotter method and morphological identification of the fungal species were implemented. The seed-borne fungi detected were Fusarium verticillioides, Aspergillus flavus, Aspergillus niger, Penicillium spp., Rhizopus spp., and Curvularia spp. However, in farmer-saved seeds, fungal incidences were significantly higher (p &lt; 0.01) than in certified seeds. To identify more effective management options, the efficacy of water and ethanol-extracted bio-fungicides from three plant species, namely, neem (Azadirachta indica), ginger (Zingiber officinale), and coffee (Coffea arabica) were evaluated. From in vitro assays, ethanol-extracted bio-fungicides have a 100% inhibitory effect on fungal growth, whilst the inhibitory effects of water-extracted bio-fungicides are 55.88% (Azadirachta indica) and 46.31% (Zingiber officinale), followed by 5.15% (Coffea arabica). For the case of an in vivo assay, maize seeds treated with water-extracted bio-fungicides have higher seed germination and seedling vigor percentages. For germination, seeds treated with water-extracted bio-fungicides have higher percentages (neem and ginger (90%) followed by coffee (72.5%)) than ethanol-extracted bio-fungicides (neem (0%), ginger (2.5%), and coffee (0%)). A similar observation is made for seedling weight. Therefore, the tested water-extracted bio-fungicides can be used in treating seeds before sowing them. Further studies on effective methods of extracting bioactive compounds, and improving their shelf life, are recommended.

Detection of Seed Borne Fungi of Sunflower

Because of adaptation to varied weather conditionsandsoil types, sunflower is the fourth most significant oilseed crop grown worldwide. Fungi play an important role in influencing grain and seed storage quality. The current study was conducted to investigate seed-borne fungi associated with sunflower seeds. Sunflower cultivar seed samples namely TAS-82, PKV SF-9, EC-68414, Morden, Surya, DRSF-108, SS-56, and LSF-8 were collected and analysed for seedmyco-flora using standard blotter and agar plate procedures. Alternaria alternata, Aspergillus flavus, Aspergillus niger, Cladosporium spp., Curvularia lunata, Fusarium oxysporum, Fusarium semitectum, Penicillium spp., Rhizoctonia bataticola, and Rhizopus species were identified as seed- borne myco-flora in two detection methods. The standard blotter approach outperformed over the agar plate method for detecting seed myco-flora because the number of colonies of seed myco-flora was greater in the standard blotter method. Morden had the highest association of seed borne myco-flora among all types, followed by TAS-82, and LFS-8 had the lowest association of seed borne myco-flora by both detection methods.

Post-harvest Fungal Infection in Arabica Coffee Beans (Coffea arabica Linnaeus) in the Coffee Center of West Sumatra Province, Indonesia

Post-harvest fungi attacks in storage can reduce the quality of Arabica coffee. The study aimed to determine the level of infection and types of post-harvest fungi in Arabica coffee beans and their quality. The research was carried out at the Phytopathology Laboratory of Plant Pests and Diseases Department and the Seed Technology Laboratory of Agronomy Department, Agriculture Faculty, Universitas Andalas, Padang, from June to August 2021. The infection level of post-harvest fungi was detected using the blotter method. Physical quality was determined based on the percentage of defects, and the quality of the coffee beans was classified according to the Indonesian National Standard (SNI). The samples were taken from three collectors in each of the three central districts of Arabica coffee, West Sumatera province (Solok Selatan, Pesisir Selatan, Lima Puluh Kota) and one sample from Solok Radjo Cooperative as a comparison. The results showed that post-harvest fungi that attacked Arabica coffee beans in West Sumatra belong to the Aspergillus genus, namely Aspergillus niger, A. flavus, and A. ochraceus. The highest post-harvest fungi attack was from Lima Puluh Kota (63.67%), and the lowest was from Solok Radjo (27%). The fungus with the highest infection rate was A. niger (38.83%), and the lowest was A. flavus (0.53%). The best quality of Arabica coffee beans was found in Solok Radjo (quality 3), with a water content that suitable with SNI standards.