Research notes: Genetics of the meiotic mutant st5

In 1970, a part-sterile plant in Uniform Test I, entry W6-4108 (from Wisconsin), was observed at Ames, Iowa. Seven seeds from this part-sterile plant gave rise to seven plants in 1971; six were fertile and one was sterile and set no seeds. In 1972, five plant progeny rows gave all fertile plants, i.e., they did not segregate fertile and sterile plants

Research Notes: Linkage Studies with a Chromosomal Interchange

Two chromosomal interchanges have been reported in soybeans by Williams and Williams (1938) and Williams (1948). We have been using the chromosomal interchange reported in 1948, which came from a cross between Glycine soja (PI 101.4048) and G. max. We received seed in 1970 from R. L. Bernard (U.S . Regional Soybean Laboratory) of PI 101 .4048 x Clark as L68-7944-2

Research Notes: Soybean linkage tests

In 1969, Walter Fehr of Iowa State University found a dwarf soybean plant (T263) in an early elite breeding population. Allelism tests have not been conducted with the other dwarfs, df2, df3, and df4. We have used this early elite dwarf mutant in crosses with our trisomics

Research notes: Inheritance of male-sterile, female-fertile mutant ms3

Two non-allelic male-sterile strains each controlled by a single recessive gene, ms1 (Brim and Young, 1971) and ms2 (Bernard and Cremeens, 1975),respectively, have been reported in soybeans. We now have evidence for a third completely male-sterile type controlled by a single recessive gene at adifferent locus from either ms1 or ms2 . As a result of the present study,this mutant was assigned a Genetic Type Collection T-number (T273) and the gene symbol ms3 by the Soybean Genetics Conmittee. This line is maintained as the heterozygote T273H

Research Notes : United States : New independent mutation: msl (Ames 2)

Five different populations have been recognized as a source of msl alleles. Genetics studies of male-sterile, female-fertile mutations conducted by Palmer et al. (1978) showed that msl (North Carolina) (T260), msl (Urbana) (T266), msl (Tonica) (T267), and msl (Ames) (T268) are independent mutations at the msl locus. Yee and Jian (1983) reported another mutation at the msl locus, designated Shennong Male-Sterile Soybean L-78-387

Research Notes : United States : New male-sterile, female-fertile mutations in soybean

Three new spontaneous independent male-sterile, female-fertile (MS-FF) mutations were used for cytological observations and for allelism tests. One of them was found in the cultivar \u27Beeson\u27. The JB and BDI mutations were found in advanced breeding populations

Research Notes : United States : Monosomics from synaptic KS mutant

Our study of unknown synaptic mutants attempts to provide more information about genetics of megasporogenesis and microsporogenesis in soybean. This study attempts also to develop aneuploid stocks to be used to establish a genetic map in soybeans. Synaptic mutants are known to produce aneuploid and polyploid plants

Research Notes : United States : A new mutation at the ms1 locus

Five different populations have been recognized as sources of ms1 alleles. Genetic studies of male-sterile, female-fertile mutations conducted by Palmer et al. (1978) showed that ms1-North Carolina (T260), ms1-Urbana (T266), ms1-Tonica (T267), and ms1-Ames (T268) are independent mutations at the ms1 locus. Yee and Jian (1983) reported another mutation at the ms1 locus, designated Shennong Male-Sterile Soybean L-78-387

Research Notes : United States : Test for apomixis in ms4 soybean

Soybean plants homozygous for the male-sterile mutation ms4 are capable of seed production in the absence of insect pollinators (Graybosch and Palmer, 1984). Cytological investigations have demonstrated the genesis of pollen grains by male-sterile plants at a frequency of 3.3% (Graybosch and Palmer, 1985). Pollen formed is identical to that of male-fertile plants, and will germinate when placed in an in vitro germination medium

Research Notes: Iowa State University, Ames, and United States Department of Agriculture

The male-sterile (female-fertile) mutant ms1 is identified by three characteristic features. Kenworthy et al. (1973) reported occurrence of twin seedlings, at a low frequency. We are reporting the two additional characteristics: failure of cytokinesis following telophase II; and production of twice as many pollen mother cells as are found in male-fertile sibs