ABSTRACT
Until recently, our research on phytoalexins concentrated on various aspects of the role of the phytoalexins medicarpin (3-hydroxy-9-methoxypterocarpan)(1), or medicarpin and maackiain (3-hydroxy-8,9-methylene-dioxypterocarpan(2), in foliage of alfalfa and in foliage and roots of red clover, respectively. With foliage, the initial objective was to determine whether phytoalexins might explain differences in host specificity and also whether they might be involved in limiting lesion size in leaf spot diseases. The work with roots arose initially out of our curiosity about the origins and relationships of phytoalexins in the roots as compared with the leaves. Unfortunately, because of our dissatisfaction with the genetics of these crops, our interest gradually turned to leaf mold of tomato leaving many interesting questions about these forage legume systems unanswered; however, in this chapter, we take the opportunity to briefly review some of that work and to present some as-yet unpublished results.
