|
|
|
“What might have been is an abstraction
Remaining a perpetual possibility
Only in a world of speculation” (T.S. Eliot, from Four Quarters)
It is likely a truism mentioning that fungal wilt diseases are some of the most intricate ones to comprehend, in the sense that demarcating between the fundamental and secondary causes and between the primary and secondary effect is complicated by the fact that the initial determinant course of infection is located in vessel elements. In the models proposed concerning the mechanics of fungal wilt diseases, it is for the most part difficult to sort out the indubitable evidence from the circumstantial one. A main reason for this situation, as we see it, is that the exact role of the pathogens in their respective hosts has not been properly studied or when they were investigated at a certain depth, many of the resulting observations were not properly recognized because they were seemingly marginal or too unusual. Indeed, comments received regarding our own observations, amongst all kinds of dubious reasons, were that they were “over-interpreted” or too “speculative”. One has to realize, however, that extensive speculation has been at the root of the classical models to explain mechanisms of symptom expression and of possible resistance regarding these diseases. In this sense, the well written paper by Talboys (1972) may be cited as a good example. One is probably not mistaken saying that the concepts presented in it have been perpetuated one way or another in many of the subsequent publications concerning these diseases, most often from observations restricted to LM studies and at low magnifications. It is perhaps for this reason that observations susceptible to challenge some of these views are awaiting for accreditation and a more decisive adhesion. This author does not feel reluctant, then, to broaden the speculation on the subject, which we nevertheless consider to be based on observations, with the hope that a more realistic comprehension of these diseases will emerge...
We invite you to download the General discussion with emphasis on the occurrence of the tissue-invading opaque matter to read the full article
|
|
|
|
|
|
|
|
|
|
|