Inheritance of percentage protein, particle size index, and alkaline water retention capacity in soft red winter wheat

Benjamin Elexy Edge, Purdue University

Abstract

Single crosses were made between wheat lines with different quality characteristics to determine the type of inheritance involved in soft wheat quality. Seven single crosses were made among eight parental wheat lines. The resulting hybrids and the parents were then grown in replicated yield trials from 1983 to 1985. Seeding rates of 355 seeds/m$\sp2$ and 118 seeds/m$\sp2$ were compared. Yield measurements were taken and the grain was tested for soft wheat quality. Quality traits measured were percentage protein, particle size index (PSI), and alkaline water retention capacity (AWRC). Seeding rate had no effect on quality. There were significant differences between hybrids and their midparents for all of the quality traits measured; however, for each trait, some of the crosses exhibited additive gene action. Dominance effects for high percentage protein were present in six of the seven crosses. Low PSI, or poor soft wheat quality, was dominant in three crosses, but additive effects for PSI occurred in the remaining four crosses. Additive effects were predominant for AWRC. Significant correlations were found between percentage protein and PSI ($-$0.52), AWRC (0.51), and yield ($-$0.14). PSI and AWRC were negatively correlated ($-$0.76). There was no correlation between yield and either PSI or AWRC, indicating that these traits can be improved without causing a reduction in yield. In another experiment, four wheat populations were developed by single seed descent. Caldwell was crossed with IN6575A2 to initiate Population 1, and the backcross was made to Caldwell for Population 2. The F$\sb2$ plants from Population 1 and the BC$\sb1$-F$\sb1$ plants from Population 2 were advanced using the single seed descent method to reach the F$\sb6$ and BC$\sb1$-F$\sb5$ generations, respectively. At this stage, the individual families were planted in 1.5m rows in the field in 1983 and 1984. The seed harvested from these rows was subjected to quality analysis and frequency distributions were determined for the traits of interest. In the populations derived from Caldwell and IN6575A2, it is evident that the two parents differ by at least two genes for percentage protein, three genes for AWRC, and three genes for PSI. The results were inconclusive from the populations developed using Beau and Lovrin-11 as parents.

Degree

Ph.D.

Advisors

Ohm, Purdue University.

Subject Area

Genetics

COinS