D. E. Alexander

Illinois Maize Breeding & Genetics Laboratory msachs at uiuc.edu
Wed Feb 11 16:24:45 EST 2004


It is with great sadness that we report the loss of our colleague,
Alex, who passed away on Monday evening (Feb 9).

Denton E. Alexander (Alex) was born on a farm near Potomac, Illinois,
on December 18, 1917. He was farm-reared and educated in rural
elementary and secondary schools in the area. From 1935 to 1937, Alex
attended Illinois State Normal University in Normal, Illinois,
receiving an elementary school teacher certificate. He taught in a
rural school, near his home, for two years. He attended the
University of Illinois Urbana-Champaign from 1939 to 1941 receiving
the B.S. degree in Agriculture.

During the early months of World War II, Alex was an aircraft engine
instructor in the U.S. Army Air Corps (1941-1943). From 1943 to 1947,
he was involved with mass spectrographic separation of uranium
isotopes at the Manhattan Project, Oak Ridge, Tennessee. He returned
to Illinois in 1947 and entered graduate school at the University of
Illinois, Urbana-Champaign and received the Ph.D. in 1950. In 1950 to
1951, he served as a postdoctoral Fellow with Marcus M. Rhoades in
the Botany Department. He joined the Department of Agronomy faculty
at the University of Illinois Urbana-Champaign, as an instructor in
1951 and attained the rank of Professor of Plant Genetics and
Breeding in 1963

In 1964, Alex established the Illinois Corn Breeders School, an
out-reach program for commercial U.S. Corn Breeders. The objective of
the school is to update corn breeders in the latest techniques in
corn breeding, biotechnology, and related disciplines. From 1964 to
2003 attendance has varied from about 80 to 150.  Following his
retirement, Alex continued to serve on the advisory committee of the
school, actively participating in the planning for the 40th annual
session to be held in March 2004.

Alex's early research in the Department of Agronomy was strongly
influenced by his postdoctoral research with Marcus M. Rhoades. That
single year's work resulted in detailed studies of the frequency of
spontaneous haploidy and of the meiotic behavior of chromosomes
during microsporogenesis of maize. Barbara McClintock had earlier
reported that bridge-like figures occur during haploid
microsporogenesis. Alex found many of these "aberrants" in the
hundreds of haploid plants he isolated. He and his students found
that spontaneous exchanges occur between nonhomologous chromosomes
and proposed these facts as evidence that modern maize is a derived
alloploid. More recent studies by others support this theory.

Immersed in cytogenetic studies, Alex became interested in Rhoades'
elongate (el) gene. Rhoades had found this recessive allele, when
homozygous, affected the second meiotic division in such a way that
microspores received the unreduced chromosome number (20). This
immediately suggested a method to inexpensively "tetraploidize" maize
on a large scale. Alex crossed the el allele into a large array of
diploid maize genotypes that included both diploid inbreds and
synthetics.

Alex's most consequential research contribution has been to the
improvement of nutritional properties of maize. The Department of
Agronomy at the University of Illinois has had a tradition of
breeding for enhanced levels of protein and oil in corn, dating back
into the nineteenth century. In the 1920s through the 1940s,
substantial effort was devoted to breeding for higher levels of both
protein and oil. These efforts largely failed, not because higher
levels of oil and protein were not reached in commercial hybrid
candidates, but because of their inferior performance. The "new" idea
that corn grain could be improved nutritionally was intriguing.
Failure to produce commercially useful high-oil inbreds, stemmed back
to an inferior parent population (i.e., the Illinois High Oil
strain). Alex concluded that a wide based population should be
recurrently selected for oil content that would serve as source of
commercial inbreds. So in 1956, he began selection for increased oil
in a 56-cultivar open-pollinated population. The program consisted of
cycles of selfing, analysis, and recombination of the highest oil
selections. This process was carried out for six cycles with budgets
of no more than $500 per year!

Alex also developed several other high-oil maize synthetics that have
received commercial interest. He used these materials to develop
high-oil single-cross hybrids to promote commercialization of
high-oil corn. In the early 1970s, Alex expanded into research on
fatty acids and later on Vitamin E. He and Charles Poneleit
demonstrated single gene control of oleic to linoleic transformation
in 1965. He was able to isolate the recessive ln1 gene that controls
conversion of oleic to linoleic fatty acids in maize. He and several
of his students evaluated the genetic variation for alpha and gamma
tocopherol in a maize synthetic and isolated two strains contrasting
in high alpha and high in gamma tocopherol.

Although the University of Illinois has a long history of research on
high oil maize, most of the research never was used in the
marketplace until about 1990. Alex's enthusiasm, perseverance, and
intellect convinced administrators of the value of high-oil corn in
the marketplace. As a result of several discussions with
administrators and several commercial companies the university signed
the first joint research and market development agreement on high-oil
maize in 1990 with Pfister-DuPont. This agreement had two components,
one involved research on high-oil corn, and the other for
Pfister-DuPont to develop a marketing system for the product.
Approximately 1.25 million acres of high-oil maize was produced in
2000. The success of this program is due in large part to Alex's
application of "sound science," enthusiasm, and a conviction that
high-oil corn had commercial value. This is a unique trait for a
plant breeder.

Alex officially retired from the university in 1988 but he remained a
Visiting Professor in corn breeding. He came to the office every day
and had the same zeal for high-oil corn that he had in 1956. Alex's
long career in corn breeding, genetics, and teaching stimulated his
enthusiasm to develop new and challenging ideas that had the
potential to help mankind, but also to add to our knowledge of the
science of plant breeding. His intellect stimulated new ideas to his
colleagues, especially the undergraduate and graduate students he
influenced to obtain advanced degrees. Some people are born to lead,
and Alex was definitely a leader in many agricultural endeavors.
During one's lifetime, most scientists do not have an opportunity to
be associated with a person of intellect, enthusiasm, compassion,
excellent work ethic, and an all-around good fellow.

--
Illinois Maize Breeding & Genetics Laboratory
http://imbgl.cropsci.uiuc.edu/




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