S. S. Sandhu*
Sujit Kumar
Since there are various biotic and abiotic factor that is responsible for causing deficiency and diseases. It leads to the reduction of yield and health decreases in gross global productivity. Fungal pathogens like Macrophomina phaseolina is soil, seed and stubble borne pathogenic fungus (Khan, 2007). Now a day it has emerged as severely damaging fungus to the agricultural world. It belongs to the family Botryosphaericeae known as anamorphic fungus in the ascomycete group (Creus et al., 2006). Its sustainability in broad tropical to subtropical regions from and to semi-arid climates favors the inhabitation of fungus in various agro-climatic conditions including Asiatic nations (Diourte et al., 1995; Wrather et al., 2001). In India there are 15 meso agro climatic and 73 subzone. The evidences explain it sustains in soil in latent-state. Initiation of the microorganism as fungal pathogen accelerates in when plant is in optimal stress condition, Macrophomina phaseolina produces asexual structures have microsclerotia and pycnidia, which can be detected in soil and host tissue utilizing various techniques and assays (Babu et al., 2011), Microsclerotia can survive in soil for 2-15 yrs. or in root debris for longer periods (Baird et al., 2003; Sarr et al., 2014). Soybean (Glycine max (L.) Merrill) is one of the most economically and nutritionally significant leguminous oilseed crops cultivated worldwide. Believed to have originated in China, it was considered one of the five sacred grains vital to the foundation of early Chinese civilization (Hymowitz, 1970). In India, soybean gained substantial commercial importance over the past six decades, especially in central and western regions. Soybean seeds are rich in macronutrients, containing approximately 40% high-quality protein and 20% edible oil (Talukdar et al., 2009). In addition to these, soybean is a dense source of essential amino acids, minerals like calcium and phosphorus, and fat-soluble vitamins including A, B-complex, C, and D. The crop also contains antioxidants and nutraceutical compounds-particularly is flavones-that have been shown to reduce blood cholesterol levels, enhance immune function, and lower the risk of cardiovascular disease, diabetes, and hormone-related cancers (Sharma et al., 2008; Kumar et al., 2014; Liu, 2010). These qualities have established soybean as a vital component of functional foods and health-promoting diets globally.
Life Cycle of Macrophomina phaseolina
Macrophomina phaseolina is a fungal pathogen that causes charcoal rot disease in various plants, including soybeans, maize, sunflowers, and other economically important crops. Understanding its life cycle is crucial for devising effective management strategies (Agarwal et al., 2013; Islam et al., 2018).
- Survival as Sclerotia: The primary survival and overwintering structure of Macrophomina phaseolina is sclerotia. These are compact masses of fungal mycelium and are capable of surviving adverse conditions in the soil for extended periods (Kaur et al., 2012).
- Germination: Under the favorable conditions like adequate moisture and temperature, sclerotia germinate, forming mycelium.
- Infection: The fungus can infect host plants directly through roots or lower stems. Infection is facilitated by fungal penetration of plant tissues.
- Colonization and Spread: Macrophomina phaseolina colonizes the vascular tissues of the host plant, causing the characteristic symptoms of charcoal rot disease, including wilting, stem necrosis, and vascular discoloration.
- Production of Sclerotia: As the disease progresses, the fungus produces new sclerotia within the infected plant tissues.
- Release of Sclerotia: When infected plant tissues senesce and decompose, sclerotia are released into the soil.
- Repeat Cycle: The released sclerotia serve as a source of primary inoculum for subsequent infection cycles, completing the life cycle.
The fungal isolates were further purified and identified based on morphological characteristics and pathogenicity tests. Morphological examination revealed the diversity of pathogens infecting soybean, highlighting variations in structure and appearance among different pathogen types. Morphological studies contribute to understanding the interactions between pathogens and their host plants. Certain morphological traits may correlate with pathogenicity virulence and host specificity.
MATERIALS AND METHODS
The present investigation was conducted on studies on charcoal rot of Soybean caused by Macrophomina phaseolina (Tassi) Goid and its Management included survey for charcoal rot, isolation, purification, pathogenicity, morphological variability and physiological studies, pathogen. The laboratory experiments were conducted in Department of Biological Sciences, Rani Durgavati University, Jabalpur (M.P.) and pot experiment was undertaken in green house.
Survey and Collection of Infected Soybean Crops from different regions in Madhya Pradesh
Study Area
Survey was undertaken in the major field soybean crops region of Madhya-Pradesh during 2016-17 and 2017-18 based on the information provided by the extension workers and reports of Indian Council Agriculture Research (ICAR, M.P.) and Jawaharlal Nehru Krishi Vishwavidyalaya (JNKVV, Jabalpur M.P.). This included important soybean cultivation areas covering 12 districts (viz, Jabalpur, Jabalpur sites, Jabalpur Khamariya, Ganjbasoda, Narshingpur, Narshingpur agriculture, Sagar, Gadarwara, Indore, Garhakota, Rewa and Tikamgarh region of Madhya-Pradesh, India as shown in Figure 1.
10.5281/zenodo.15835903