A comparison of selection methods for reduced shattering in wild rice.

To test for genetic variability for grain retention, additional to that conditioned by a two-complementary-gene system, and to compare selection systems for reduced shattering, two forms of selection were conducted in Zizania palustris cv. Netum. The selection criterion was strength of individual grain retention on main stems at maturity as measured with a hand-held spring operated meter. Two cycles of mass selection in the greenhouse and one cycle of half-sib family selection in the field, both at a 10% selection intensity, produced two populations which were compared with each other and with Netum at Grand Rapids and Excelsior, Minnesota. Progress from selection was 49.6% for two cycles of mass selection and 15.9% for one cycle of half-sib family selection. Heritability estimates for grain retention were 0.58 and 0.55 at the two test sites.