Date of Award
Master of Science
Genetics, Development and Cell Biology
Harry T. Horner
A male-sterile, female-sterile mutant was identified in a transposon-tagging study in soybean (Glycine max L.). This mutant displayed abnormalities in both micro- and mega-sporogenesis, as well as gametogenesis. Vegetatively, the mutant showed no visible differences from the wild-type phenotype. Analyses of male meiotic chromosomes were done to better understand any issues that could occur to cause sterility. Wild-type and mutant anthers and ovules were cleared throughout their development, followed by confocal scanning laser microscopy to look for any abnormalities, and to determine the timing of abortion in both the male and female organs in the mutant. Additionally, scanning electron microscopy was done to observe the differences between wild-type and mutant anthers and male cells near maturity and mutant abortion. Results indicate there are chromosomal segregation abnormalities in the mutant male meiosis. Mutant anther development proceeds through meiosis to form abnormal triads, tetrads and pentads to the released microspore stage, after which the resulting male cells become irregularly shaped and eventually abort. Mutant megasporogenesis proceeds through meiosis from megaspore mother cell through two meiotic divisions resulting in the tetrad stage which then progresses to the single megaspore and to the early formation of a megagametophyte which ceases further development These first-time cytological and anatomical results were compared with an already-published molecular study of this sterile soy mutant and to provide insights into this dual sterility in soybean.
Katherine A. Thilges
Thilges, Katherine A., "Microscopic characterization of a transposon-induced male-sterile, female-sterile mutant in Glycine max L." (2016). Graduate Theses and Dissertations. 15238.