Reena Singh

Mycorrhiza in Control of Soil Borne Pathogens

Speedy development of agriculture is vital to the progress of a country. For securing maximum crop production, the agricultural practices have evolved into highly technified and sophisticated plant production systems. Until recently, the management of plant diseases in these systems was done exclusively by the use of broad-spectrum chemical pesticides. However, there is reason for concern about the potential damage to ecosystems and pollution of groundwaters resulting from the widespread use of these chemicals on agricultural crops that led scientists to develop disease resistant transgenic plants as an alternative approach for controlling pathogens.

Co-composting of physic nut (Jatropha curcas) deoiled cake with rice straw and different animal dung

To address the dispensing of this growing volume, a study on utilization of jatropha (Jatropha curcas) deoiled cake through compost production was carried out. The deoiled cake was composted with rice straw, four different animal dung (cow dung, buffalo dung, horse dung and goat dung) and hen droppings in different proportions followed by assessment, and comparison of biochemical characteristics among finished composts. Nutrient content in finished compost was within the desired level whereas metals such as copper, lead and nickel were much below the maximum allowable concentrations. Although a few finished material contained phorbol ester (0.12 mg/g), but it was far below the original level found in the deoiled cake. Such a study indicates that a huge volume of jatropha deoiled cake can be eliminated through composting.

A study of abandoned ash ponds reclaimed through green cover development.

Green capping is one of the popular methods to re-vegetate abandoned ash ponds of coal based thermal power plants thereby lowering the risk of contamination to the surrounding environment. It has innumerable advantages such as prevention of dust emission, checking soil erosion, stabilizing the surface areas of ash, preventing potential ground water contamination, and finally, adding native vegetation cover, which is very vital in the long term. During the early nineties and later, various reclamation projects were carried out on fly ash dumps, but until date, there have not been any initiatives to assess the alterations in physicochemical and biological properties of fly ash resulting from implementation of these reclamation projects. In the present study, three abandoned ash ponds, located in India, that were reclaimed during 1998–2003 are investigated. Marked alterations in nutritional status, microbial population, and microbial activities have been observed in reclaimed ash ponds.

Diversity of AM (Arbuscular mycorrhizal) Fungi in Wheat Agro-climatic Regions of India

AM (Arbuscular mycorrhizal) fungi are important yet unknown components of biodiversity in the agricultural fields in India. To study their diversity and habitat relationships, we characterized and enumerated spores in 55 fields of wheat from 11 agro-climatic regions of India, varying in climatic and edaphic characteristics. The AM fungal spore count, species richness, most frequent species, and intra-radical colonization were studied in various samples drawn from these regions. A total of 165 samples were collected at the time of the wheat harvest. These samples were used as trap cultures and multiplied in a green house for a period of one year, which yielded 34 species scattered over 6 genera. The genera Glomus Tulasne & Tulasne occurred most frequently, constituting 89.1% of the total species. The number of species in a given region ranged from 1?9. Glomus albidum Walker & Rhodes and G. macrocarpum Tulasne & Tulasne were found to be the most commonly occurring species.

Biotechnological Advancements in Industrial Production of Arbuscular Mycorrhizal Fungi: Achievements, Challenges, and Future Prospects

The recent technological advancements in arbuscular mycorrhizal (AM)–plant symbiosis have helped improve the potential applications of mycorrhizal biotechnology in agriculture, horticulture, landscaping, phytoremediation, and other areas of plant market. The most common conventional methods used for large-scale production of AM fungi include cultivation in pots with sterilized soil, aeroponics, hydroponics, or greenhouse-based in vivo methods. However, these techniques suffer from severe problems of cross-contamination in the inoculum production; therefore, production of high-quality inoculum remains a major challenge. The most advanced method is transformed root organ culture (ROC) to produce AM propagules without adulterated microbial contaminants under strictly controlled sterilized conditions after pure AM fungi are inoculated into the transformed root organ. The scientific breakthroughs and advancements in the field of mycorrhizal research during past two-to-three decades have resulted in new technological developments with different types of products and diverse modes of their applications. For example, mycorrhizal formulations are available in the market for seed coating, liquid applications, or biostimulants. An established symbiosis in the plant roots confirms the adaptation even under unsuitable soil or unfavorable climatic conditions. These advantages have led to an increasing demand for mycorrhiza products in the last few years. There is a growing interest among the enterprises in the developed as well as developing world for the production of mycorrhizae-based inoculum given the fact presented by the emerging market trends in developing economies. However, even today it is not possible to trace out the absolute origin of the fungal species/strain used in commercial inoculum. Despite the regulatory challenges imposed by the regulatory bodies to maintain the highest quality standards, a significant number of commercialized products may still be found in the market which claims for extensive and effective mycorrhizal colonization even though they lack the necessary potential for this. This review provides an updated overview of the recent developments in the technology adoption and commercial production of mycorrhizae-based quality inoculum.