|Improved Rice and Greater Use - 71
NEW VARIETIES KEEP COMING
EARLY MATURITY MAKES PROGRESS
We now have several thousand short-stature selections with heading dates ranging from earlier than Colusa to as late as Calrose. These are in various stages of purification and backcrossing to pick up additional characteristics.
Two early-heading mutants each from CS-M3 and CS-S4 were increased last winter for yield trials at 3 locations in 1972. Twelve very early selections will be given yield tests in 1972, as will 19 early-heading advanced experimentals.
HIGH YIELDS FROM EARLY-MATURING SELECTIONS
Considerable breeding time will be needed, but findings indicate good possibilities of crosses of Italica livorno with Colusa, Caloro, Earlirose, and Calrose.
GENETICS APPLIED TO IMPROVE MAXIMUM HEAD YIELD
Genetic means are being exploited for improving uniformity in ripening and maximum translucency. These factors contribute to maximum head yield by providing more uniformity in ripening time. The result is better control of harvest so grain does not get so dry as to undergo sun checking and kernel breakage.
TASTE TESTS EXPAND
Taste tests rated Caloro and CS-S4 about the same in flavor and texture. In Puerto Rico they were both preferred over 3 medium-grain rices (Calrose, CS-M3, and S6183), which all rated about the same but with CS-M3 slightly better in texture than the other two.
LONG-GRAINS GET MORE ATTENTION
Long-grain experimental varieties in general have less seedling vigor than California medium and pearl. Even so, several yielded more at Biggs than any of the varieties now grown in California. 5915C-35-8 yielded over 80 sacks in 1970 and over 77 sacks in 1971. It did well also in Butte, Glenn, and Sutter counties, and poorly in cooler zones. Further quality tests are needed. When harvested at several moisture levels it ranged disappointingly low (23-43%) in head yield. If this characteristic is confirmed next year, it can be marketed only if parboiled.
Statewide tests are planned for '72 for a long-grain developed in South. Seed characteristics are like Starbonnet's, excellent stiff straw, heads about 3 days earlier than Calrose, and yielded higher than any California variety.
Three promising lines were found among 16 early long-grain and 16 early medium-grain lines from Southern states. Two of the 3 are early long-grains that seem adapted to cooler areas. Though most long-grains are poorly adapted to cool regions, these averaged more than 7700 lb per acre and were about 9 days earlier than Calrose.
GROWTH REGULATORS FLUNK TESTS
Rice yields were not affected significantly by the growth regulators CL-84479, CL-84741, DPX-1840, TO-6265, TD-6266, and TD-6733, even though applied as suggested by their manufacturers.
HYBRID RICE NOT SEEN NEAR
Hybrids involve many problems, basic findings show. Reason for low seed set on cytoplasmic male-sterile rice plants was shown to be the flowering behavior in the field. Unlike other cereals, rice florets opened only once, regardless of whether fertilization occurred. They remained open for only about an hour, and the time of day of opening varied with the variety. Until basic genetic work reveals more promise for hybrid rice, the plant-breeding resources seem better used in breeding improved pure-line varieties.
DRIVE BUILDS FOR HIGHER PROTEIN
Analysis indicates that high protein will most likely be in a variety that matures very early. Lines recently developed at the International Rice Research Institute are to be crossed with high-protein lines.
Lysine, the essential amino acid most limiting-in nutrition by rice, tends to be highest in lines with highest total protein, strengthening the drive to develop high-protein lines.
Protein content appears related to plant height, heading date, and grain weight in the lines studies, though environment has a strong influence. To assure that inheritance is not obscured by environment, breeding for increased protein will require careful control of nitrogen, planting date, and plant spacing.
NOTE: The brewing industry prefers low-protein rice.
IMPORT SORTING CONTINUES
Foreign breeding programs keep providing imports that receive careful scrutiny in growth tests under quarantine.