Comparative Fastness of AM Development in Roots of Different Rice Cultivars Due to their Varying Responsiveness to AMF

Mycorrhiza varies in their responsiveness among the different plant and also within the species of a plant. This was established in case of various rice varieties in our previous study. Our hypothesis was that as AM fungi behaves like pathogen with the independent or negatively dependent variety group, a defense mechanism may triggered which restricted the fungi to grow in those plant root where as dependent variety group should allow the fungi to grow and there may be some differences in the penetration phase to colonization phase of the AM fungi between the two variety groups. Based on the above, 8 rice varieties were selected with varying responsiveness for the study with challenged inoculation. Root colonization process for AM development was examined at 10 to 15 days of seed germination. The colonization process in low or non responsive variety groups are slower than that of the high responsive variety groups. Although, there is no difference in pre and post colonization structures but differ in intensity, the high responding varieties allowing faster and earlier establishment of mycorrhiza than the low or non responsive varieties.