IV.10. The genetic male sterile barley collection.
E. A. Hockett. Western Region, ARS, U.S.D.A. and Plant and Soil Science Department, Montana State University, Bozeman, Montana 59715, U.S.A.
In last year's report (2) an excess of male sterile plants was found in the expected 3:1 segregation of msg,,bw. Additional data obtained in 1973 showed a ratio of 44:12 of fertile:male sterile plants with this mutant thus fitting a 3:1 ratio with P = .7 - .5.
Two new numbered loci have been assigned to the genetic male sterile series as shown in Table 1. These results from crossing a homozygous male sterile plant with a heterozygous male sterile plant of the previously numbered loci, show that msg 25r and msg 26u are not allelic with msg1 through 24 or with each other.
The only new symbol assigned since last year's report is msg ,cx found in the cultivar Hector (Table 2). Segregation for fertile:male sterile is shown in Table 2 for some mutants where no data has been reported previously. All mutants segregated 3:1 for sterility except msg,,cw where fewer male sterile plants were found than expected. The shortage of plants for the msg,,bz mutant leaves the question of fit to a 3:1 ratio unresolved. Actually, it appears that msg,,bh and msg,,bz are partial steriles rather than male steriles since they set 92.5 and 36.9% seed respectively. The seeds found under the bags on heads of msg,,cs, msg,,cv and msg,,cw will be grown out in 1974 to check for possible chance outcrossing.
Table 2. Ratios of fertile to sterile plants in F2 and selfing behavior of sterile plants.
References:
1. Hockett, E. A. 1972. Coordinator's report on the genetic male sterile barley collection. Barley Genet. Newsletter 2:139-144.
2. Hockett, E. A. 1973. The genetic male sterile barley collection. Barley Genet. Newsletter 3:87-89.
