Volume 7 - 2024 - issue 2

1. Unravelling the Diversity, Root Colonization, and Morphological Features of Arbuscular Mycorrhizal Fungi Associated with Invasive Plant Species of Sirmaur, Himachal Pradesh, India

Authors: Kaur M, Singh PK

Recieved: 11 April 2024, Accepted: 26 June 2024, Published: 06 September 2024

This study assessed the diversity and colonization patterns of arbuscular mycorrhizal fungi (AMF) associated with selected invasive plant species, i.e., Parthenium, Cannabis, Mimosa, Lantana, and Asclepias spp. Soil samples were collected from the rhizosphere of five invasive plants in the Baru Sahib area, Sirmaur, Himachal Pradesh, India. The samples were analyzed using various methods, including wet-sieving, decanting, and microscopy. Fifty-six morphologically distinct AMF species belonging to 15 genera were identified. Glomus species were the most abundant, followed by Acaulospora and Rhizophagus. Parthenium hysterophorus exhibited the highest root colonization percentage (94.8%), while Asclepias curassavica had the lowest (61.6%). Lantana camara had the highest number of AMF spores in the soil samples, while Cannabis sativa had the lowest spore number. These findings provide valuable insights into the diversity and colonization patterns of AMF associated with invasive plant species, which can contribute to our understanding of the ecological interactions between invasive plants and soil microbial communities.

Keywords: Ecological impacts – Mycorrhization – Root Colonization – Symbiotic associations

2. Diversity and seasonal variations of endophytic fungi associated with Terminalia chebula Retz. (Combretaceae) of Tripura, India

Authors: Tripura S, Debbarma P, Paul S, Saha R, Datta BK, Saha AK.

Recieved: 04 May 2024, Accepted: 21 August 2024, Published: 23 September 2024

Endophytic fungi are microbes living within the interior organs of plants without showing any symptoms of the diseases. These fungi are recognized for their bioactivities, including antimicrobial, anticancer, antifungal, and antioxidant properties, etc. Despite having such importance, less research has been conducted to uncover the fungal endophytes colonizing different tissues of many important medicinal plants. Thus, the current study was undertaken to isolate and determine the diversity of culturable endophytic fungi associated with the medicinal plant Terminalia chebula Retz., collected from five different sites representing three different seasons (summer, monsoon and winter) in Tripura, Northeast, India. A total of 697 culturable endophytic fungal isolates were represented by sixteen genera, and a few sterile forms were recorded from 1,125 tissue segments of Terminalia chebula. The phylum Ascomycota dominated the endophytic fungal composition. The fungal endophytes like Diaporthe sp., Penicillium exsudans, Colletotrichum sp., and Corynespora torulosa were predominantly isolated from the host plant. The colonization and relative frequency of endophytic fungi were maximum in the leaf tissues, followed by barks and roots. The monsoon season harbored the maximum number of fungal isolates (285) compared to the summer (234) and winter (178) seasons. Significant differences were noted in the diversity of endophytic colonization among different study sites and various plant organs in different seasons. The diversity indices revealed maximum fungal diversity in the bark tissues compared to leaf and root tissues. The highest species richness was at the Jalaya site in comparison to the other sites while species diversity of fungal endophytes was highest during the summer season and lowest in winter. The results indicated that the study site, type of tissues and season influenced the endophytic fungal communities of the host plant, Terminalia chebula. These diverse endophytic fungi probably possess the ability to secrete bioactive compounds for curing several diseases, bioinoculants for plant protection, drug discovery in pharmaceutical sectors and biofertilizers in agricultural fields.

Keywords: Ascomycota – Chebulic myrobalan plant – Fungal diversity – Seasons

3. Fusarium oxysporum f. sp. lycopersici, the causal agent of vascular wilt disease of tomatoes: From its taxonomy to disease management

Authors: Rhouma A, Hajji-Hedfi L, Atallaoui K, Kouadri AM, Khrieba MI 2024

Recieved: 12 December 2023, Accepted: 26 August 2024, Published: 26 September 2024

Tomato (Solanum lycopersicum) is one of the world's most vital vegetable crops, holding immense agricultural, nutritional, and research significance. However, the Fusarium wilt disease, caused by Fusarium oxysporum f. sp. lycopersici, poses a severe threat to its global cultivation. This review paper focuses on the comprehensive management of Fusarium wilt disease and the associated taxonomic framework. It highlights the global significance of tomatoes, emphasizing their importance around the world. The review covers various aspects, including taxonomy and genetic variation of the pathogen, host range, disease symptoms, economic implications, factors affecting epidemiology, geographical distribution, disease cycle, and various management strategies. Moreover, it explores different management approaches, including chemical control, biological control, cultural practices, resistance breeding, soil solarization, and grafting. This comprehensive review underscores the strategies needed to protect tomato crops, ensuring food security on a global scale despite the challenges posed by Fusarium wilt.

Keywords: Fusarium wilt – management practice – Solanum lycopersicum – sustainable