Diversity of Botryosphaeriaceae and Diaporthe species associated with postharvest apple fruit decay in Serbia

Family Botryosphaeriaceae and the genus Diaporthe (fam. Diaporthaceae) represent diverse groups of plant pathogens, which include causal agents of leaf spot, shoot blight, branch and stem cankers, dieback, and pre and postharvest apple fruit decay. Apple fruit with the symptoms of light to dark brown decay were collected during and after harvest from 2016 to 2018. Thirty selected isolates, which pathogenicity was confirmed, were identified and characterized based on multilocus phylogeny and morphology. Five species from the family Botryosphaeriaceae and two from the genus Diaporthe (fam. Diaporthaceae) were discovered. The most commonly isolated was Diplodia seriata followed by Botryosphaeria dothidea. In this work, Diaporthe rudis is described as a new postharvest pathogen of apple fruit. Diplodia bulgarica, Diplodia sapinea, Neofusicoccum yunnanense, and Diaporthe eres are initially described as postharvest apple and D. sapinea as postharvest quince and medlar fruit pathogens in Serbia. As species of the family Botryosphaeriaceae and the genus Diaporthe are known to cause other diseases on their hosts, have an endophytic nature, and a wide host range, findings from this study imply that they may become a new challenge for successful fruit production.

Morphological and phylogenetic characterisation of endophytic fungi associated with the grapevine flowers in China

The harvest from grapevines is berries which are derived from the flowers. Even though numerous studies have been conducted to understand the pathogens associated with grapes, less is known about the fungi associated with the flowering stage and their potential for infecting fruit as latent pathogens. In the present study, 99 endophytic strains were isolated from the calyptra of grape flowers of four different grape cultivars (Italia, Jingxiangyu, Kyoho and Zexiang). The isolates were Alternaria, Cladosporium, Diaporthe and Epicoccum species. Alternaria was the most abundant genus with 88 strains of A. alternata. Four Cladosporium species were identified including two new host records (Cladosporium ramotenellum and C. anthropophilum) and one new species (Cladosporium endoviticola sp. nov.). Diaporthe eres and a novel Epicoccum species (Epicoccum endophytica sp. nov) were also identified. This study provides evidence that some grape fruit pathogens occur as endophytes in flowers. The study enhances the current knowledge of grape pathogens and can be used to develop sustainable management strategies.

How Do Trichoderma Genus Fungi Win a Nutritional Competition Battle against Soft Fruit Pathogens? A Report on Niche Overlap Nutritional Potentiates

We present a case study report into nutritional competition between Trichoderma spp. isolated from wild raspberries and fungal phytopathogenic isolates (Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.), which infect soft fruit ecological plantations. The competition was evaluated on the basis of nutritional potentiates. Namely, these were consumption and growth, calculated on the basis of substrate utilization located on Biolog® Filamentous Fungi (FF) plates. The niche size, total niche overlap and Trichoderma spp. competitiveness indices along with the occurrence of a stressful metabolic situation towards substrates highlighted the unfolding step-by-step approach. Therefore, the Trichoderma spp. and pathogen niche characteristics were provided. As a result, the substrates in the presence of which Trichoderma spp. nutritionally outcompete pathogens were denoted. These were adonitol, D-arabitol, i-erythritol, glycerol, D-mannitol and D-sorbitol. These substrates may serve as additives in biopreparations of Trichoderma spp. dedicated to plantations contaminated by phytopathogens of the genera Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.

Pengaruh Lokasi Sumber Rizobakteri Terhadap Daya Hambat Pertumbuhan Koloni (Phytophthora palmivora) Patogen Penyebab Busuk Buah Kakao (Theobroma cacao L.) Secara In Vitro

Abstrak. Penelitian ini bertujuan untuk mengetahui pengaruh lokasi sumber isolat rizobakteri terhadap daya hambat pertumbuhan koloni patogen penyebab busuk buah kakao secara in vitro. Penelitian ini dilaksanakan di Laboratorium Ilmu dan Teknologi Benih Jurusan Agroteknologi, Fakultas Pertanian, Universitas Syiah Kuala Darussalam Banda Aceh dari bulan September sampai November 2018, menggunakan Rancangan Acak Lengkap non faktorial. Faktor yang diamati yaitu jumlah isolat rizobakteri yang berpotensi dalam mengahambat pertumbuhan koloni patogen penyebab busuk buah kakao dari dua lokasi pengambilan yang berbeda yaitu dari Tripa dan Gleumpang Minyeuk dengan 3 kali ulangan pada tiap perlakuan yang dilanjutkan dengan Uji Beda Nyata Jujur pada taraf 5% pada hasil uji F yang signifikan. Hasil penelitian ini menunjukkan pengambilan rizobakteri dari dua lokasi yang berbeda berpengaruh sangat nyata terhadap daya hambat pertumbuhan koloni patogen penyebab busuk buah kakao, yang dijumpai pada perlakuan isolat rizobakteri GM 8/2 dengan daya hambat 58,23% dan GM 8/3 dengan daya hambat 51,59% dengan aktifitas penghambat sedang. Juga berpengaruh sangat nyata terhadap laju penghambat pertumbuhan koloni patogen penyebab busuk buah kakao yang dijumpai pada perlakuan isolat rizobakteri TRI 4/7 dengan rerata laju penghambatan 4,76 mm/hari. Isolat rizobakteri yang mampu dalam melarutkan fosfat dijumpai pada perlakuan TRI 3/11, TRI 4/6, TRI 6/14, TRI 7/4, TRI 8/2, TRI 8/4, TRI 8/8, TRI 8/9, GM 3/6, GM 5/6, GM 6/1, GM 6/5, GM 7,/9, GM 8/3, GM 8/8 dan GM 8/11. The Effect Of Source Rizobacteria On The Inhibitory Power Of Growth Colony (Phytophthora palmivora) Pathogens Causes Of In Vitro Rotten Cocoa Fruit (Theobroma cacao L.) Abstract. This study aims to determine the effect of the location sources of rhizobacterial isolates on the inhibitory power of growth of pathogens causing cocoa fruit rot by in vitro method. This research was carried out at the Seed Science and Technology Laboratory of the Department of Agrotechnology, Faculty of Agriculture, Syiah Kuala Darussalam University Banda Aceh from September to November 2018, used a non factorial Completely Randomized Design. The factors observed were the number of rhizobacterial isolates which had the potential to inhibit the growth of pathogens causing cacao fruit rot from two different locations, namely Tripa and Gleumpang Minyeuk with 3 Repeat times for each treatment were followed by an Honest Real Difference Test at the level of 5% on a significant F test result. The results of this study indicate rhizobacterial uptake from two different locations had a very significant effect on the growth inhibitory power of cacao rotten pathogenic colonies, which was found in the treatment of GM 8/2 rhizobacterial isolates with inhibition of 58.23% and GM 8/3 with inhibitory power 51.59% with moderate inhibiting activities. It also has a very significant effect on the rate of growth of the inhibitor of cacao rotten fruit pathogens found in the treatment of TRI 4/7 rhizobacterial isolates with an average inhibition rate of 4.76 mm / day. Rhizobacterial isolates capable of dissolving phosphate were found in the treatment of TRI 3/11, TRI 4/6, TRI 6/14, TRI 7/4, TRI 8/2, TRI 8/4, TRI 8/8, TRI 8/9, GM 3/6, GM 5/6, GM 6/1, GM 6/5, GM 7, 9, GM 8/3, GM 8/8 and GM 8/11.

Metabolomics to Exploit the Primed Immune System of Tomato Fruit

Tomato is a major crop suffering substantial yield losses from diseases, as fruit decay at a postharvest level can claim up to 50% of the total production worldwide. Due to the environmental risks of fungicides, there is an increasing interest in exploiting plant immunity through priming, which is an adaptive strategy that improves plant defensive capacity by stimulating induced mechanisms. Broad-spectrum defence priming can be triggered by the compound ß-aminobutyric acid (BABA). In tomato plants, BABA induces resistance against various fungal and bacterial pathogens and different methods of application result in durable protection. Here, we demonstrate that the treatment of tomato plants with BABA resulted in a durable induced resistance in tomato fruit against Botrytis cinerea, Phytophthora infestans and Pseudomonas syringae. Targeted and untargeted metabolomics were used to investigate the metabolic regulations that underpin the priming of tomato fruit against pathogenic microbes that present different infection strategies. Metabolomic analyses revealed major changes after BABA treatment and after inoculation. Remarkably, primed responses seemed specific to the type of infection, rather than showing a common fingerprint of BABA-induced priming. Furthermore, top-down modelling from the detected metabolic markers allowed for the accurate prediction of the measured resistance to fruit pathogens and demonstrated that soluble sugars are essential to predict resistance to fruit pathogens. Altogether, our results demonstrate that metabolomics is particularly insightful for a better understanding of defence priming in fruit. Further experiments are underway in order to identify key metabolites that mediate broad-spectrum BABA-induced priming in tomato fruit.