Abstract
Oat (Avena saliva L.) has a severe lodging problem prior to grain ripening. One way to reduce lodging is by reducing plant height. This study was conducted to determine the genetic control of plant height, to evaluate the potential of dwarf oat using early generation testing and, to determine the effect of a "major" dwarfing gene on grain yield and other agronomic traits in oat grown in Central Texas. In Spring 1991, six crosses were made with a single dwarf parent and six normal (tall) parents. Fl plants were grown in Summer 1991. F2 populations from each of the normal x dwarf crosses were space planted in the field in Spring 1992. At plant maturity, plants from each cross were separated into four height categories (dwarf, semidwarf, intermediate and tall). The 18 bulk F3 hybrids (3 height categories in each of 6 crosses) and the 7 parents were grown in spring-planted replicated yield trials at two field locations in Spring 1993. Yield components and other agronomic traits (plant height, test weight, panicle length, panicle exsertion and harvest index) were determined at one location. Five of six crosses had a good fit to the expected 3:1 ratio for dwarf versus tall F2 plants, indicating that a single dominant gene conditioned dwarf height. Early generation testing of F3 bulks allowed an evaluation of the agronomic potential of dwarf oats. Grain yields were significantly lower for dwarf bulk F3 populations than for tall F3 bulks or for tall parents. Test weights also were significantly lower for dwarf populations than for tall bulks or tall Parents. In addition, dwarf and semidwarf F3 bulk populations did not exsert their panicles from the flag leaf sheaf. Strong positive associations between grain yield and plant height and grain yield with panicle exsertion and between test weight and both plant height and panicle exsertion indicate that the development of high yielding dwarf oat cultivars with high test weight will not be an easy task.
Almeida, Juliano Luiz de (1994). Effect of a "major" dwarfing gene on grain yield and other agronomic traits in oat. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1994 -THESIS -A447.