ANNOUNCEMENTS
The main objective of the present study was to compare 15 arbuscular mycorrhizal fungal isolates (8 parents representing 3 Glomus species under the same genera Glomaceae and their 7 stable hyphal fusion progenies) at molecular and functional levels to find out their similarities/variations as well as whether the hyphal fusion progenies are having superior functional characteristics than their parents, so that these progenies can be recommended for soil reclamation, environmental protection, and enhanced agricultural production. The hyphal fusion progenies were developed through hyphal fusion technique at Centre for Mycorrhizal Research Centre, TERI earlier and these progenies and their parents were used in the present study in order to test their potential towards “designer" isolates that have the required characteristics drawn from both the parents. The study was carried out under three categories of experiments- in vitro studies in bottom ash amended medium and non-ash amended medium; microcosm studies with five different plants (maize, marigold, tomato, garlic and onion) in two substrates viz., bottom ash and loess soil; and molecular studies using Amplified Fragment Length Polymorphism. The functional and growth parameters selected for comparison were the effect of AMF on nutrient uptake, heavy metal uptake, glomalin production, root and shoot length, root colonization, root and shoot fresh weight and dry weight etc. Though the molecular studies showed that Progeny 9 (P61xL36) and Progeny 12 (P61xI20) share almost equal amount of genetic information with their parents, the study results of in vitro and microcosm studies did not confirm this finding. In vitro studies showed that hyphal fusion progeny 14 (L11xI20) and parental isolate P46 showed high tolerance for a wide range of metals; but microcosm studies with five different plants in bottom ash substrate showed that different AMF isolates showed varying metal uptake capacity in different host plants. Similarly for other functional and growth parameters also, a lot of variations were observed in the study results in microcosm and in vitro experiments. For example, in vitro studies showed maximum production of total protein (containing glomalin) by parental isolate L7 in non-ash amended medium whereas microcosm studies in loess soil showed maximum total protein (glomalin) production by maize plants colonised with parental isolate L7, P57 in marigold, P61 in garlic, Progeny 16 (L36xI20) in tomato and Progeny 7 (P57xL37) in onion; and in bottom ash substrate, maize plants colonised with Progeny 9 and garlic plants colonised with Progeny 6 (P57xL7) showed maximum value. Based on the study results, it is concluded that the effect of hyphal fusion progenies and their parents vary for each functional and growth parameter depending upon the substrate as well as host plant.
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