Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

First Advisor

Timothy P. Croughan


Callus formation and plant regeneration rates for both immature panicle and anther culture of rice were studied in several populations, including parents, F$\sb1$, F$\sb2$, F$\sb3$, and backcrossed generations. Significant genotypic differences in regeneration and callus formation rates were observed. In immature panicle culture, F$\sb1$'s generally produced rates of regeneration close to their high parents. Generation mean analysis of regeneration rates revealed the importance of dominance effects (d) and epistatic effects (aa, ad, and dd) in immature panicle culture. In contrast, production of callus by 12 F$\sb1$ hybrids in another culture was closely related to the low parents, suggesting that suppression of callus formation was dominant. Generation mean analysis revealed significant contributions from dominance (d) and epistatic effects to the trait. Plant regeneration rates in another culture appear heritable. The mean regeneration rates in F$\sb1$'s showed overdominance and recessive characters in some crosses and significant reciprocal differences were found for Lemont/Short Tetep. A total of 6,332 immature panicles and 375,873 anthers were cultured, produced 28,395 immature panicle derived regenerates and 15,003 anther derived regenerates. Evaluation and selection of superior lines within this material has provided germplasm potentially useful for rice varietal improvement.