RICE INTRODUCTIONS

Plant introductions grown at the Imperial Valley Field Station at El Centro.

Rice genetics and breeding programs are in progress at many locations in the world. These programs are a source of new desirable plant characteristics which are being introduced into this country and used in breeding programs in California. The University of California Imperial Valley Field Station at E1 Centro is providing an essential link in a network of facilities which make these introductions possible. The new introductions are grown under quarantine and evaluated in a preliminary trial before they can be released either for use in genetic studies at the California Agricultural Experiment Station at Davis or for breeding better varieties at the Rice Experiment Station at Biggs.

During 1969 over 400 different lines of promising breeding material were provided by the International Rice Research Institute at Los Banos, in the Philippines.

Selections made at the Imperial Valley Field Station in 1969 are being grown in 1970 at four locations in California.

In 1970 an additional 400 selected lines and about 500n unselected lines are being grown under quarantine at E1 Centro. This program is cooperative between the U.S. Department of Agriculture, the Rice Experiment Station at Biggs, and the University of California.

RICE GENETICS

Extension workers testing new varieties in rice-growing areas before release.

Genetic studies at Davis in 1969 were a continuation of crosses made at Biggs in 1967. The objectives were to determine the nature of inheritance of high protein content, cold-water tolerance of seedlings, short plant stature, high tillering ability, and male sterility. The last characteristic is essential for the production of hybrid rice.

Other genetic studies--pursued by graduate students at the University of California at Davis--are:

1) Improvement in seedling vigor and tolerance to adverse conditions during stand establishment.

2) Effect of plant height on rice yields and the ratio of grain to straw.

3) Inheritance of seedling characters in rice

4) The inheritance of flowering time in a cross between the variety Colusa and the Japanese variety Kitaminori.

5) Genetic and environmental relationships to alpha-amylase activity and seedling growth of rice.