Researchers determined that the "eui" (elongated uppermost internode) trait, which may prove useful for hybrid rice seed production, is controlled by the same recessive gene in several mutants.

Breeding lines with genetic male sterility induced by light manipulation were harvested for more detailed studies.

First generation crosses to study seedling vigor, submergence tolerance and cold tolerance were also made.

Researchers imported 378 accessions form the International Rice Research Institute in the Philippines. These included first generation hybrids between California cultivars and interesting donors; wild Oryza species; the core collection of Asian cultivated rice (Oryza sativa); and other potential donors selected for seedling vigor, cold tolerance, submergence tolerance, wide compatibility and cytoplasmic male sterility.

Researchers also began efforts to introduce the wide compatibility gene into California germplasm to facilitate the use of exotic parents to introduce other new genes and to exploit hybrid vigor in wide crosses.

Research into molecular genetics and tissue culture will be greatly facilitated by a recently renovated laboratory at UC Davis. Initial work will focus on characterization of California rice germplasm with "molecular markers" and genetic analysis of important agronomic traits.

Geneticists feel the "EUI" trait- short for elongated uppermost internode-may help them in their search to develop hybrid rice.