Influence of arbuscular mycorrhizal fungi on the growth of agricultural crops in arsenic amended soil | |
| Author | Khan, Bayezid Mahmud |
| Call Number | AIT Thesis no.NR-09-04 |
| Subject(s) | Mycorrhizal fungi Arsenic Crops--Effect of arsenic on |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Natural Resources Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. NR-09-04 |
| Abstract | Agricultural crops are getting contaminated with arsenic because of irrigation with arsenic contaminated groundwater and causing significant health risk to animal and human health through soil-crop transfer. Since 1993 arsenic contamination in groundwater has drawn attention in Bangladesh. Out of 64 districts, 59 districts are affected with arsenic contamination in groundwater. Mycorrhizal fungi have their most significant effect on Phosphorus uptake. They have also been shown to reduce arsenic contamination to the agricultural crops. Hence, the study was performed, i) to assess the mycorrhizal status of some standing crops grown in two arsenic affected areas of Feni and Comilla district and a arsenic non-affected area of Chittagong district, Bangladesh, ii) to know the role of arsenic on seed germination and seedling growth in petridish under laboratory condition, and also iii) to determine the role of arbuscular mycorrhizal fungi (AMF) on crops growth in arsenic amended soil. For testing seed germination and seedling growth under laboratory condition, arsenic concentrations of 00 (Control), 01, 05, 10, 25, 50 and 100 ppm were used while for determining the role of AMF on crops growth in arsenic amended soil, six agricultural crops were grown in three levels (10ppm, 50ppm and 100ppm) of arsenic amended soils with or without mycorrhizal inoculation. Study of mycorrhizal status of standing crops revealed that the infection percentage and intensity of infection differ from species to species in the same location and within the same species in three different locations. Among the three districts, species growing in the Chittagong, showed higher percentage of infection (Mycelium colonization ranging from 98% to 38% and spore population in the rhizosphere soil ranging from 187±15.7 to 56±07.8 in 100⁻¹g soil) compared to same species growing in Feni (Mycelium colonization ranging from 81% to 23% and spore population ranging from 144±16.5 to 33±05.7) and Comilla (Mycelium colonization ranging from 77% to 15% and spore population ranging from 127±09.7 to 28±05.8) districts. Results of seed germination and seedling growth under laboratory condition indicated that, at higher concentrations of arsenic, the seed germination and seedling growth was affected more than the lower concentrations. Germination reduction was maximum (100%) in Vigna unguiculata and Cicer arietinum while minimum (49.05%) in Cucumis sativa at the highest level (100ppm) of arsenic concentration used in the study. A positive growth response to AMF was observed in all the selected crops in the experiment for determining the role of AMF on crops growth in arsenic amended soil. Shoot and root length; fresh and dry weight of shoots and roots; vigor, volume and quality indices etc. were higher in case of AMF inoculated pots in comparison to their respective AMF non-inoculated treatments and the growth parameters decreased significantly (P<0.05) with the increase rate of arsenic concentrations. Higher pigments concentration in leaf and less arsenic content in shoot were also recorded in mycorrhiza inoculated plants. Among the six studied species in the nursery, Zea mays accepted mycorrhizal association rapidly with high mycorrhizal infection and in response low arsenic uptake in shoot (ultimately less arsenic poisoning in human health), whereas Brassica oleracea showed the opposite result. Hence, Zea mays is highly recommended for the arsenic affected area followed by Cucumis sativus, Vigna unguiculata, Cicer arietinum, Allium sativum and Brassica oleracea. The toxicity of arsenic was affecting seed germination and seedling growth both in laboratory and nursery condition but severity were more in laboratory condition compared to nursery. Results of the study ensure the reduction of seed germination and seedling growth in arsenic contaminated soil and also indicate that mycorrhizal inoculation could minimize the harmful effects of arsenic in the growth of agricultural crops both in the nursery as well as in the field. |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. NR-09-04 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Development and Sustainability (DDS) |
| Academic Program/FoS | Natural Resources Management (NRM) |
| Chairperson(s) | Schmidt-Vogt, Dietrich; |
| Examination Committee(s) | Shipin, Oleg ;Perret, Sylvain ;Mridha, Md. Amin Uddin; |
| Scholarship Donor(s) | The Netherlands; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2009 |