**Professor Emeritus, Mark J. Bassett - A Brief Professional Biography
(July 2005)**

Mark J. Bassett was born in Washington, Indiana on May 15, 1940. He
spent his primary school years in West Lafayette, Indiana, his middle
school years in Peewaukee, Wisconsin, and his high school years in
Waukegan, Illinois. After graduating in 1963 from Lake Forest College
with a B.A. degree in economics, he earned his M.S. and Ph.D. degrees at
the Horticulture Department of the University of Maryland. His area of
academic specialization was plant breeding and genetics. He took his
first faculty job in May 1970 at the University of Florida in the
Vegetable Crops Department (now Horticultural Sciences) as a lettuce
breeder. About 1975, he abandoned the lettuce breeding project because
of duplication within the University of Florida system, and he elected
to work with the genetics of common bean for the remainder of his
career, while assisting the carrot breeding program of the late C. E.
Peterson (USDA at the University of Wisconsin) in the field trials in
Florida.

He decided early to specialize in the genetics and cytogenetics of
common bean. Over time, the genetics of seed coat colors and patterns
became the dominant area of work although he worked on the genetics of
any other traits in common bean, whether simply or quantitatively
inherited, as opportunity presented itself. For example, he used a
quantitative genetic approach to the study of pod length. Similarly, his
student, R. Manshardt, used quantitative measurements of stigma position
on bean pistils in interspecific crosses between *Phaseolus vulgaris* x
*P. coccineus*. Genetic investigation involving other crops were also
conducted with collaborators, e.g., 1) the effects of temperature and
other experimental variables on the expression of resistance to
nematodes in tomatoes and 2) the genetics of resistance to bacterial
leaf spot in pepper.

During the 1980\'s, he directed the programs of several students who
worked on bean cytogenetics. Simon Cheng worked on chromosome morphology
at diplotene. L. Hung used gamma irradiation of pollen to develop twelve
lines with semi-sterility mutations. M. Ashraf subsequently discovered
that the semi-sterility was due to heterozygosity for chromosome
translocations. M. Ashraf also developed five primary trisomic lines
from the chromosome translocation lines and developed homozygous
translocation lines with characterized interaction patterns, i.e., known
to have chromosomes different from each other.

Shree Singh at CIAT sent M. Bassett materials that had unusual sterility
characteristics. M. Bassett established that the sterility was
cytoplasmic. A student, S. MacKenzie, began molecular genetic
investigation of this cytoplasmic sterility from S. Singh, and she has
made molecular genetic investigation of cytoplasmic male sterility the
basis of her subsequent career. The secondary research interests also
included a substantial commitment to the genetics of resistance to the
Bean Golden Mosaic Virus, which became a significant problem in Florida
after hurricane Andrew introduced the virus to Florida in 1992. There
was also a program to develop new marker gene traits by induced
mutations, using the gamma ray treatment of seeds to obtain the mutants.
Numerous viable marker mutations were developed and characterized, and a
few of them were successfully mapped.

On May 11, 1977, he sent a letter to Dr. R. Prakken at Wageningen, The
Netherlands, hoping to obtain seeds of bean varieties that had been
reported to exhibit xenia from the bean germplasm collection at
Wageningen. At the request of the chairman of the Genetics Department,
another faculty member sent him a reply informing him that R. Prakken
had died earlier that year. Soon thereafter he became increasingly
committed to work on the genetics of seed coats, taking up the work
where R. Prakken had left it with his summary treatises written in 1970,
1972 and 1974. He discovered early that many north European bean
varieties are very poorly adapted to the climate of north Florida, and
this led to experimental difficulties in the field and greenhouse
because of cultural problems. To solve this challenge, he developed a
breeding line, 5-593, over the next few years. The development of line
5-593 was completed in 1985, and 5-593 has excellent adaptation to the
local climate, small black seeds and a very compact, determinate plant
habit.

The basic strategy of seed coat genetic investigations since 1985 has
been to backcross all known genes (as many as possible) for seed coat
color and pattern (and other traits) into the recurrent parent line
5-593, usually to the BC~3~ level. Subsequently, various known marker
genes in the 5-593 genetic background were crossed with each other to
create combined genotypes. Thus, a large set of genetic tester stocks
were developed carrying one or more exactly known seed coat marker genes
in a common genetic background. Many of those genetic tester stocks have
been put in the Genetic Stock Collection for common bean at the Plant
Introduction Station at Pullman, Washington. Subsequently, he developed
a protocol for using the genetic tester stocks to make further
investigations of seed coat genetics.

In the process of developing the genetic tester stocks, a number of seed
coat genes carried cryptically by 5-593 were exposed, viz., the *cl*
gene for circumlineated patterns of partly colored seed coats, the *Fib*
gene for restriction of numerous partly colored seed coat patterns, and
the *Mic* (formerly *Mip*) gene for a dotting pattern (with *c j*)
emerging from the micropyle and curving along (toward the caruncula end)
both sides of the seed in widening swaths.

Among the more notable achievements of his program of investigation into
seed coat genetics are the following:

> 1\) discovered the *t*^cf^ gene for partly colored seed coats that
> (with *P V*) maintains color in flowers, whereas *t* expresses partly
> colored seed coats and white flowers, in the presence of genotype *P
> V*.
>
> 2\) discovered that the *cl* gene expresses a physical groove in the
> surface of the seed coat at the boundary of the white and colored
> zones in partly colored seed coats.
>
> 3\) development of the gene symbol *z*^sel^ for the gene (new allele
> at *Z*) controlling sellatus and piebald patterns of partly colored
> seed coats, originally reported by von Tschermak.
>
> 4\) discovered the *bip*^ana^ gene for the Anasazi pattern and
> *bip*^vgt^ for the virgata pattern of partly colored seed coats.
>
> 5\) discovered the *Fib* gene (unpublished data), which expresses the
> fibula arcs trait and restricts various partly colored seed coat
> patterns.
>
> 6\) discovered that the *Gri* locus is a synonym for *P*; and besides
> *p*^gri^, he discovered three additional alleles at *P* expressing
> various patterns in seed coats and flowers, viz., *p*^stp^, *p*^hbw^,
> and *p*^mic^.
>
> 7\) proposed using a bracket convention when presenting gene symbols
> for *very* tightly linked genes in the 'complex *C* locus', viz.,
> using *C* to designate pattern control (or sometimes *c*^u^) while
> giving the genotype at *R* (oxblood red seed coat gene) or *Prp* (the
> purple pod gene) as separate gene symbols within the brackets.
>
> 8\) discovered the *gy* gene for greenish yellow seed coat color (with
> cool growing conditions), as in the Azufrado Peruano market class; and
> he discovered a second gene, tentatively *Chr*, that depends on *gy*
> for expression and converts the corona and hilum ring to greenish
> yellow (even in the presence of *v*^lae^ for dark corona) . The *Gy*
> gene is tightly linked to *C* and may yet be proven to be within the
> 'complex *C* locus'.
>
> 9\) discovered that the hilum ring color factor *D* is allelic with
> the *Z* gene for partly colored patterns. No one prior to M. Bassett
> intercrossed the genotypes for seed coat color with those for partly
> colored patterns on such an extensive scale and with the segregating
> seed coat genes largely determined by the prior development of genetic
> stocks.
>
> 10\) discovered that the *L* gene (reported by Schreiber) for partly
> colored patterns is allelic with the *J* gene for seed coat color.
> Thus, *J* was discovered to play important dual roles in seed coat
> color and the expression of partly colored patterns. He discovered the
> *j*^ers^ gene (from 'Early Wax'), which plays unique roles in partly
> colored seed coats while having no expression with *T P C*, whereas
> *j* expresses loss of color in the corona and dull seed coats with *T
> P C* (usually with immature seed coat colors).
>
> 11\) discovered the *V*^wf^ gene from *P. coccineus* for black seed
> coats but white flowers, and he discovered that the *v*^lae^ gene
> controls strong anthocyanin expression in the corona zone.
>
> 12\) with collaborator P. Miklas, discovered the *rk*^cd^ gene in
> 'NW63\' for dark red kidney color expression that is dependent on the
> genotype at *C* for its expression, and they discovered the *rk*^p^
> gene in 'Sutter Pink' that is dependent on very dry air for good pink
> color expression.
>
> 13\) discovered the *Prp*^i^*-2* gene, an independent locus for
> intensified anthocyanin expression in a syndrome of plant organs,
> especially expressing purple pods.
>
> 14\) with collaborators P. Miklas and M. Blair, discovered the *R-2*
> gene (unpublished data), an independent locus for dominant red seed
> coat color expression with unique features not observed with *R*.
>
> 15\) with long-term collaborator P. McClean, mapped the seed coat
> color and pattern genes *T*, *Bip*, *C*, *Z*, *J*, *G*, *V*, and *Gy*,
> using the mapping system developed by P. Gepts with BAT93 and Jalo
> EEP558.

16\) discovered the *wb* gene from *P*. *coccineus* for (nearly) white
banner with *P T V*.

> 17\) with collaborator P. Miklas, is currently (July 2005)
> investigating:
>
> a\) the inheritance of the bicolor flower trait transferred from *P*.
> *coccineus*
>
> ('Painted Lady') to *P*. *vulgaris*,
>
> b\) the expression of *Sal Am* (genes from *P*. *coccineus*, now
> transferred to *P*.
>
> *vulgaris*), i.e., whether *Am* is pleiotropic for scarlet flowers and
> oxblood red seed
>
> coats (with *P C J G B v*) or, alternatively, the oxblood red seed
> coat color is
>
> controlled by a gene (tentatively *Oxb*) closely linked to *Am*, and
>
> c\) the possible role of *Fib* (or some other unknown gene) in
> changing the dark
>
> blue (methyl violet 39/2) flowers expressed by *t Prp*^i^*2 V* to pale
> blue or white by
>
> partial dominance.