Effect of Sclerotium rolfsii Sacc. on seed germination and seedling vigour of groundnut germplasm.

摘要

Studies were conducted to determine the effect of Athelia rolfsii on the seed germination and seedling vigour of 12 groundnut germplasms (UG-6, JAL-17, UG-20, UG-17, JAL-26, UG-19, UG-9, UG-21, UG-10, UG-15, UG-16 and UG-22). Seven healthy seeds from each of the 12 groundnut germplasms were surface sterilized and treated with 7 days old sporulating culture of the fungus and dried for 72 h at room temperature. At 10 days after inoculation, observations on percent germination were recorded. The length of radicle and plumule, fresh and dry weight of 10 days old healthy and fungi-treated seedlings were recorded. The A. rolfsii was grown separately on autoclaved rice medium and inoculated with spore/mycelial suspension prepared from 7 days old culture. Autoclaved soil in earthen pots was mixed with inoculum and covered with polythene bags and left for 24 h in a pot house. Healthy surface sterilized seeds of different germplasm were sown in pots. Seeds sown in uninoculated pots served as control. At 15 days after sowing, observations were recorded. Five seedlings were randomly selected from each treatment. Results showed that the germination and vigour of 10 days old groundnut seedlings of the different germplasms were suppressed by A. rolfsii. The germination was suppressed in all the groundnut germplasms tested, but the maximum reduction was observed in UG-22 (16.03%), followed by UG-15 (11.61%) and UG-21 (11.40%) compared to the uninoculated controls. A significant decrease in plumule length was observed in UG-10 (26.76%) and UG-22 (23.17%), followed by JAL-26 (21.43%), and reduced radicle length was observed in UG-22 (26.37%) and UG-10 (23.68%), followed by UG-15 (20.69%), whereas the plumule length was less affected in UG-16 (4.07%) and radicle length in UG-6 (3.70%) compared to the uninoculated control. The fresh and dry weights of different groundnut seedlings registered significant decreases in the case of treated UG-16 (21.65 and 28.83%), followed by UG-22 (21.02 and 22.86%) compared to the uninoculated control. Nevertheless, the fresh weight was less affected in JAL-17 (6.50%) and dry weight in UG-17 (3.65%) compared to the control. The germination and vigour of groundnut seedlings of the different germplasms was reduced by A. rolfsii inoculated soil. The germination was markedly suppressed in all the groundnut germplasms tested, but the maximum reduction was observed in UG-16 (20.97%) and UG-9 (16.14%) compared to the control. The plumule length was significantly reduced in UG-15 (27.66%) and JAL-26 (24.26%), followed by UG-22 (21.01%) and radicle length in UG-19 (43.16%) and UG-21 (27.48%), followed by UG-15 (27.31%), while plumule length in JAL-17 (0.34%) and radicle length in UG-17 (2.16%) was less affected compared to the control. Results also showed the significant reduction of fresh weight in UG-21 (23.47%) and UG-9 (23.43%), followed by UG-15 (23.23%), and dry weight in UG-22 (28.97%) and UG-16 (28.83%), followed by UG-21 (21.97%) compared to the control.