Cucurbit Genetics Cooperative Report 12:58 (article 25) 1989
A Second Look at the Glabrous Male-Sterile (gms) Character in Watermelon
B.B. Rhodes, B.A. Murdock and J.W. Adelberg
Clemson University Edisto Research and Education Center, Blackville, SC
Watts (5) recovered the gms character from irradiated seed in 1957 and reported on the variant in 1962. Although the variant behaved as a single recessive gene, there were two notable exceptions. One glabrous plant grown in the greenhouse produced enough pollen to set 35 seed in a fruit on a homozygous normal plant. Watts was not able to recover subsequent progeny from this cross. He also noted that a single selfed heterozygote produced a 1:1 ratio of hairy:glabrous instead of a 3:1 ratio as expected. the class with fewer individuals than expected was the homozygous normal class.
Production of gms gms gametes in a tetraploid line carrying the gms character is reduced (1, 3). However, the variant segregated faithfully in the tetrasomic condition (4). Ray and Sherman (2) suggested that chromosome desynapsis was the cause of male sterility in the gms prototype.
We now have four lines derived from a single glabrous, male-fertile variant of the gms material. Three of the lines exhibit some male fertility. Female fertility was related to male-fertility in these lines. Male flowers with viable pollen occur two or more weeks after the appearance of the first female flower.
The gms variant is more than a well-behaved Mendelian recessive. Glabrousness is recessive to hairiness, but sterility and glabrousness are not pleiotropic effects of the same gene. Male-sterility and female-sterility are related, suggesting that the meiotic process is flawed (2). The extremely late development of male fertility in new recombinants may provide a far superior system for hybrid seed production than previously envisioned.
- Love, S.L., B.B. Rhodes and P.E. Nugent. 1986. Controlled pollination transfer of a nuclear male-sterile gene from a diploid to a tetraploid watermelon line. Euphytica 35:633-638.
- Ray, D.T. and J.D. Sherman. 1988. Desynaptic chromosome behavior of the gms mutant in watermelon. J. Heredity (in press).
- Rhodes, B.B. and L.C. Blue. 1986. Segregation of glabrous male-sterile in an autotetraploid line of Citrullus lanatus. Cucurbit Genetics Coop. Rpt. 9:84-86.
- Rhodes, B.B. and R.T. Nagata. 1988. Evidence for a tetrasomic line in watermelon. Cucurbit Genetics Coop. Rpt. 11:57-59.
- Watts, V.M. 1962. A marked male-sterile mutant in watermelon. Proc. Amer. Soc. Hort. Sci. 81-498-505.