100 Seconds with Ray F. Evert
My first article published in AJB was “Some aspects of cambial development in Pyrus
communis” in 1961. My principal research interest at the time was the vascular
cambium and seasonal development of the secondary phloem in trees. Katherine Esau
was my major professor, and my Ph.D. thesis (Phloem structure in Pyrus communis and
its seasonal changes. Univ. Calif. Publ. Bot. 1960.32, 127-194) was patterned after her
similar study on the grapevine.
During the 34-year period I have published in AJB the process of peer review,
acceptance, and publication remained unchanged (two peer reviewers and one or two
referee reviewers, if necessary). During the 1970s and early 1980s the period between
acceptance and publication became unreasonably long. In 1981-82, I served as Chair of
an Advisory Committee for the AJB which was charged with providing recommendations
to solve the problem. Subsequently (1983-85), I chaired a follow-up Committee on
Business Management of the AJB.
Two articles (my latest) were published in AJB in 1994, and dealt with vastly different
topics (“Ontogeny of the vascular bundles and contiguous tissues in the maize leaf
blade” by A.M. Bosabalidis, R.F. Evert, and W.A. Russin; the other, “Development and
ultrastructure of the primary phloem in the shoot of Ephedra viridis (Ephedraceae)” by
R.A. Cresson and R.F. Evert.
As indicated, my early research was on the vascular cambium and seasonal
development of the secondary phloem in trees (eudicots and conifers). With the
advent of electron microscopy, I began ultrastructural studies on the phloem of woody
and herbaceous eudicots, monocots, and gymnosperms. This was followed by extensive
studies on the comparative ultrastructure of seedless vascular plants, ranging from
Psilotum to a broad array of ferns. In 1978, my research shifted to studies on the
development and structure of leaves of selected C3 and C4 plants, utilizing bright-field
and electron microscopy and a variety of experimental procedures to gain a greater
understanding of structure-function relationships in leaves. Among the plants studied
were several economically important crop plants: barley, maize, sugarcane, sugar beet,
and potato. Finally, my group concentrated on developmental and structural changes
accompanying the transition of maize and barley leaves from importers to exporters of
photoassimilates, a process commonly refereed to as sink-to-source transition. I
emphasize “group” because, without my graduate students (25 PhDs, 23 MS) with their
energy, enthusiasm, intelligence, and innovativeness, I would have achieved far less of
my research goals.
My research interests never strayed far from the phloem. It was during a seminar in
1953, while working for the MS in Botany at Penn State, that I became interested in
phloem. There and then I decided to pursue a PhD, with some aspect of the phloem as
my thesis topic. When I told this to my MS mentor, Dr. David Kribs, he told me that I
must go to UC-Davis to work with Katherine Esau. Shortly after my conversation with
Dr. Kribs I received a letter from Dr. Esau informing me that Dr. Kribs had written to her
on my behalf, and that she would be happy to accept me as one of her graduate
students; moreover, she had a teaching assistantship for me. I became her “phloem
ray.”
Electron microscopy was in its infancy in the early 1960s, so I could not have foreseen
the ultrastructural research undertaken by my students and me. Nor could I have
foreseen the splendid collaborative research undertaken on aspects of leaf structure
and function with Walter Eschrich (University of Gottingen, Germany) and C.E.J. Botha
(Rhodes University, South Africa).
It is difficult to choose one or two of my articles published in AJB that stand out above
the others. One of the earliest articles (“Callose substance in sieve elements”, 1964) is
significant because it demonstrated that the sieve pores of uninjured sieve elements are
virtually devoid of callose. The article, which was the most fun, was “Observation on
penetration of linden branches by stylets of the aphid Longistigma caryae” (1968), in
which we demonstrated that sieve tubes greater than one year old are still functional.
Why have I chosen AJB as one of the journals in which to publish? AJB is the premier
botanical journal with a broad readership. Its reproduction of micrographs, both photo
and electron, is superb, a matter of great importance to an anatomist. And then, there
is a matter of loyalty—AJB is “home.”