VESICULAR-ARBUSCULAR MYCORRHIZAL DEVELOPMENT IN THE BRASSICACEAE IN RELATION TO PLANT LIFE-SPAN

Six hundred and forty six taxa of Brassicaeae were inoculated under gl asshouse conditions with Glomus intraradices SCHENCK & SMITH root inoc ulum and assessed after 5 weeks for vesicular arbuscular mycorrhizal ( VAM) development. Of the 649 taxa, 123 (18.9%) showed some level of VA M development. Chi-square analysis showed no significant differences i n VAM development between annuals and perennials. Analysis of publishe d reports of mycorrhizal development in crucifers also failed to demon strate any relationship between VAM development and life span in cruci fers. VAM development in these plants included only internal hyphae an d vesicles; no arbuscules were observed in any of the 3230 root segmen ts examined. These data suggest that VAM development in crucifers is p robably non-functional and that life span characteristics do not affec t the apparent VAM development in glasshouse inoculated specimens.