Anuar M.S.K.A., Hashim A.M., Ho C.L., Wong M.Y., Sundram S., Saidi N.B. &Yusof M.T. (2025) In vitro characterization of fungal isolates from soil as a potential fungal-based biostimulant for suppressing the growth of Ganoderma boninense as well as enhancing oil palm growth. - Sydowia 77: 231-243. Oil palm crops play a crucial role in economic growth and food security for many countries but are susceptible to Ganoderma boninense (Gb), which causes basal stem rot (BSR). Despite the use of biological control, the diseases have not been limited. Biostimulants are substances that promote plant growth, and some microbial-based biostimulants with biocontrol functions have been shown to be useful in mitigating biotic stress. Through in vitro conditions, this study characterizes the ability of fungal isolates to suppress Gb and exhibit plant growth-promoting traits. Among nineteen isolates, six exhibited significant antagonis-tic activity against Gb PER71 in dual culture and Poison food agar assays. Molecular identification revealed that the six fungal isolates belonged to the genus Mucor, Aspergillus, Xenomyrothecium, Acrophialophora and Trichoderma. All isolates were subjected to determining plant growth-promotion (PGP), including indole acetic acid (IAA) and ammonia productions, phosphate solubilization, hydrogen cyanide (HCN) and catalase activity. Overall, all isolates have shown at least three PGP traits. Through API (R) ZYM analysis, the fungal isolates were revealed to have phosphoric hydrolase, ester hydrolase, peptide hydrolase and glycosidase activities. This study suggests that fungal isolates are an excellent candidate for developing potential fungal-based biostimulants against Gb and promote plant growth in oil palm.
The endophytic mycobiota of 84 symptomless mature potato plants collected in 21 farms each of two Iranian provinces, Ardebil and south Kerman, were studied. A total of 491 isolates yielded 52 different fungal taxa. Some of the taxa isolated are known as potato pathogens and a few of them (especially Fusarium spp.) potential mycotoxin producers. Alternaria spp. were dominant in both sites in the aerial and Fusarium spp. in the underground parts. Almost all other taxa were present at frequencies <10 %. The two sites were quite similar with regards to their evenness values, but the species richness of the Kerman samples was higher. The most common endophytic species displayed an organ specificity that allowed distinguishing between aerial and underground organs.
During studies on filamentous oleaginous fungi from industrial area soil of Dombivili, India, some lipase producing mucora-ceous fungi were isolated. Based on polyphasic approaches a new species is described here under the family Lichtheimiaceae of the order Mucorales. Lichtheimia indica sp. nov. forms monopodially, sympodially and verticillately branched sporangiophores, as well as sub-globose to ellipsoidal sporangiospores. Abundant bulbous giant cells and chlamydospores are observed on MEA, PDA and SMA media. The new species grows best at 35 degrees C and has its upper maximum growth at 40 degrees C. Lichtheimia indica is distinguished from the other Lichtheimia species by ITS and LSU rDNA sequences. The phylogenetic tree provides a strong support for the sibling relationship between the newly described species and L. ornata and L. corymbifera. This is the eleventh species within the genus Lichtheimia.
Mechanistic insight into stereospecific antifungal activity of fungicides against pink root disease (PRD) caused by Setophoma terrestris has not been obtained yet. In this study, we analyzed the Priaxor fungicide for inducing resistance against S. terrestris via novel defense marker genes, R1, PR5, Lectin, Lox, Osmotin and RGA29 and defense-related enzymes such as catalase (CAT), peroxidase (POX), superoxide dismutase (SOD), along with Lamardo and Rovral fungicides on three different onion cultivars. The lowest PRD incidence was observed in Priaxor with 9.5 % compared to the non-treated controls with 47.7 %. Bulbs of Allium cepaYellow cultivar treated with Priaxor had the highest yield followed by other cultivars. The highest gene expression was observed in Priaxor-treated cultivars followed by other fungicides ranging from 1.39-4.54-fold increase. Defense-related marker genes, R1, PR5, and RGA29, were up-regulated in onions in response to the onion pink root pathogen. Similarly, CAT, POX, and SOD activities increased in Priaxor-treated onions up to 3.6-fold. Our data indicated that various fungicides could have subtle differences in efficacy profiles inducing resistance in onion cultivars which may translate to improved management against S. terrestris as a fungal root pathogen.
Gupta S. & Saxena S. (2024) Identification and evaluation of pathogenicity of endophytic Botryosphaeria dothidea in apple (Malus domestica) in India. - Sydowia 77: 211-218. Botryosphaeria dothidea is known to exist as an endophyte and latent pathogen in woody plants. In the current study, B. dothidea was isolated as an endophyte from the healthy fruit of Malus domestica procured from Mandi district in Himachal Pradesh, India. The isolate was identified using morphological, molecular (ITS 1 and 4, and EF1-alpha), and phylogenetic analyses. Botryosphaeria dothidea is regarded as versatile in terms of host range, as they have been discovered in various plant species and have also been identified as potential plant pathogens while remaining dormant. Hence, pathogenicity of the isolated strain was tested on wounded and unwounded apple fruit. Lesions were observed on wounded and unwounded apple fruit inoculated with isolated B. dothidea, and 100 % fruit damage was observed within a week in wounded apples. Botryosphaeria dothidea was re-isolated from the test fruit and identified based on morphological features, which confirmed Koch's postulates. To our knowledge, this is the first instance of B. dothidea being isolated as an endophyte and latent pathogen from apple fruit in India. The results also suggested that endophytes might be latent pathogens capable of becoming active under changing environmental conditions, disrupting the equilibrium between host and endophyte antagonism.
