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• Induced Resistance Potential of Penicillium citrinum CTND-2405 against anthracnose disease on basil (Ocimum basilicum L.)

  Nguyen Huu Tri, Nguyen Thi Thuy Dung, Tran Nghia Trinh Du, Nguyen Phuc Hau, Tran Thi Bich Quyen, Le Thanh Toan

  Date Received: 31-10-2024 / Date Accepted: 21-01-2025 / Date Published: 23-01-2025

   Abstract PDF (VIETNAMESE)

  Rhizosphere fungi are known for their ability to antagonize plant pathogens, promote growth, and induce disease resistance in plants. This study aimed to evaluate the potential of Penicillium citrinum CTND-2405, isolated from rhizospheric soil, in inducing resistance on basil (Ocimum basilicum L.) against anthracnose caused by Colletotrichum sp. Basil seeds were soaked for 4 hours in either a spore suspension of P. citrinum (106 cfu/ml) or sterile water, with or without artificial inoculation of Colletotrichum sp. Polyphenolic accumulation and fluorescence responses in leaf tissues were observed under a fluorescence microscope. In greenhouse experiments, five treatments were tested: seed soaking with P. citrinum spores, soaking in sterile water, additional spore applications at 3, 6, 9 days post-planting, and chemical fungicide applications. Results showed that seed soaking with P. citrinum followed by pathogen inoculation triggered earlier and stronger polyphenolic accumulation and fluorescence responses. Combining seed soaking with spore applications further reduced anthracnose incidence and severity, and disease control efficiency up to 59.92% compared with the control treatment.

  DOI: https://doi.org/10.31817/tckhnnvn.2025.23.1.02

• Antifungal Ability of Nanochitosan against Colletotrichum acutatumL2 in Post Harvest Tomato Fruit

  Le Thanh Long, Nguyen Thi Nga, Nguyen Cao Cuong, Tran Ngoc Khiem, Nguyen Thi Thuy Tien

  Date Received: 07-05-2015 / Date Accepted: 02-12-2015

   Abstract PDF (VIETNAMESE)

  This study examined the antifungal effect of nanochitosan on Colletotrichum acutatum L2 isolated from anthracnose infected tomato both in vitro and in vivo. The results demonstrated that nanochitosan inhibited the spore germination and the growth of C. acutatum L2. Inhibitory effect of 50% and 90% mycelial diameter and dry biomass was achieved at the nanochitosan concentration of 0.75 g/l and 1.53 g/l, 0.46 g/l and 1.1 g/l, respectively. Concentration of 1.6 g/l nanochitosan completely inhibited the growth of C. acutatum L2. In in vivo, nanochitosan could control the growth of C. acutatum L2 on tomato fruits. After 10 days, the nanochitosan concentration of 4 g/l inhibited 76% the development of lesion diameter and MIC50 was achieved at concentration of 1.14 g/l.

• Detection of ColletotrichumSpecies Causing Anthracnose of Chili by Polymerase Chain reaction

  Nguyen Duy Hung, Ha Viet Cuong, Hoang Chung Lam

  Date Received: 21-01-2019 / Date Accepted: 19-02-2019

   Abstract PDF (VIETNAMESE)

  Anthracnose caused by Colletotrichumspp. is one of the most destructive diseases of chili in Vietnam and worldwide. Identifying Colletotrichumspecies that cause anthracnosebased on morphological characteristics often causes confusion. The objective of the study was to design specific primer pairs for rapid and accurate diagnosis of Colletotrichumfungus causing anthracnose by PCR(polymerase chain reaction). In the study, based on the Internal TranscribedSpacer (ITS) region and the intergenic region of apn2 and MAT1-2-1genes (ApMat) four specific primer pairs were designed. Four species,i.e.C. truncatum, C. fructicola, C. gloeosporioides sensu strictoandC. siamensethat cause chili anthracnose in the Red River Delta and some other provinceswere detected.The study also showed that a modified rapid extraction protocol using NaOH was highly effective to prepare DNA samples from Colletotrichumcultures for PCR reaction. PCR analyses using the newly designed specific primers on 52 chili Colletotrichumisolates collected from 13 provinces, mainly the Red River Delta, revealedC. siamenseas the most abundant species (51.9%of total isolates), followed by C. fructicola(21.2%), C. truncatum(15.4%), and C. gloeosporioidessensu stricto (9.6%).

• Influence of Intercropping and Fertilizer for Mondo Grass on Weeds, Disease and Insect Pests at Young Tea Garden

  Nguyen The Hinh, Nguyen Dinh Vinh, Nguyen Van Tuat

  Date Received: 05-09-2012 / Date Accepted: 28-11-2012

   Abstract PDF (VIETNAMESE)

  Intercropping of Mondo grass (Ophiopogon japonicus Wall) into tea garden of cv. Kim Tuyen (1-3 years old) is aimed to increase the land coverage, create the favorable conditions for the tea growth and improve the farmers’ income. The impacts of mondo grass intercropping and seven fertilizing formulae on pest occurrence (diseases, insects and weeds) and plant damages were investigated. The major findings are: (i) 15 weed species were found in tea garden, (ii) Mondo grass intercropping can reduce the biomass of weeds in the tea garden, and (iii) The mondo grass is not the host plant of pests on tea. The intercropping of mondo grass led to changes in solar radiation, soil moisture and land coverage which favor pest occurrence and damage such as increasing the density and damage of Empoasca flaescens Fabr. & E. onukii Mats., Helopelthis theivora Waterh, and Colletotrichum camelliae Marasmius equinis Muler Derk. but reduce the density of Physothrips setiventris Bagn and Oligonychus coffeae Niet. on the tea plants.

• Biological Characterization of Streptomycessp. VNUA30 Strain with Antagonistic Activity Against Pathogenic Fungi CausingDisease on some Plants

  Nguyen Thi Thanh Mai, Nguyen Thanh Hai, Nguyen Thi Thu, Tran Thi Dao, Nguyen Xuan Canh

  Date Received: 04-05-2022 / Date Accepted: 05-07-2022

   Abstract PDF (VIETNAMESE)

  Diseases caused by pathogenic fungi account for 80% of plant diseases resulting in a global crop yieldreduction. The use of chemical fungicides for the control of fungal diseases causes environmental pollution and affects human health. Biocontrol using actinomycetes having antifungal activity was reported to be effective and biosafe. This studyfound that actinomycete strain VNUA30 exhibited a broad-spectrum antifungal activity against five plant pathogenic fungi, i.e. Colletotrichum gloeosporioides, Fusarium oxysporumf.sp. cubense(FocTR4), Corynespora casiicola, Sclerotium rolfsii, and Diaporthe sp. with inhibition rate of 62.50%; 52.58%; 72.22%; 57.77%; and 95.37%, respectively. Biological studies showed that strain VNUA30 was able to produce melanoid pigment, siderophore, H2S and IAA, assimilate citrate, reduce nitrate, liquefy gelatin, degrade urea and produce extracellular enzymes chitinase, cellulase, xylanase, protease, and pectinase. Combining the morphological and biochemical characteristics with the 16S rRNA sequence analysis, this strain was identified as Streptomyces deccanensis VNUA30. The results confirmed that actinomycete strain VNUA30 is a potential strain as bio-control agent for fungal diseases on plants with high efficiency.

• Isolation and Selection of Trichodermaspp. Antagonists against Pathogens CausingAnthracnose in Mango

  Pham Thi Ly Thu, Le Trung Thanh, Luu Thi My Dung, Ha Viet Cuong, Nguyen Duc Thanh, Nguyen Thi Hong Hai

  Date Received: 12-07-2021 / Date Accepted: 29-10-2021

   Abstract PDF (VIETNAMESE)

  Mango is a key crop and provides high economic efficiency in the Mekong Delta. However, its yield and quality are seriously affected by anthracnose disease. In order to select Trichoderma spp. with high antagonistic activity against disease fungi, 17 soil samples were collected from healthy plots in Hau Giang and other provinces in the Mekong Delta. A total of 56 strains of Trichodermaspp. were isolated and 14 strains were selected for high antagonistic activity against fungi causing anthracnose. Among those, strains Tr.X1, Tr.X2, Tr.X3, Tr.X4, T1, M2 and Tr.X2, Tr.X3 exhibited the most antagonistic activity from 77.76-86.25% inin vitro,and 75.3-72.01% in the net house. The strains were identified as Trichoderma harzianum(Tr.X2) and Trichoderma asperellum(Tr.X3) and they have potential of biological control to anthracnose in mango.