Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate

Department name when degree awarded

Plant Breeding

Committee Chair(s)

Marion W. Pedersen


Marion W. Pedersen


The use of F1 hybrids for commercial production of such cross-pollinated crops as corn, sorghum, sugar beets, onions, and pearl millet suggests the feasibility of using this technique for alfalfa. Production of F1 hybrids of commercial value is dependent on the use of breeding material expressing good combining ability. In order to obtain precise estimates of combining ability for quantitative characters in alfalfa, it is necessary to produce all possible single crosses among a number of parents. The single cross seed required is difficult to obtain due to the vegetative reproduction and isolation required; and, subsequently, limited testing of this type has been conducted in alfalfa. Testing breeding material for combining ability based on seed production has been more limited than testing based on forage yield or various other measurements. In this experiment a diallel crossing system was used to test the general and specific combining ability of five alfalfa clones previously selected for good general combining ability.

The report is based on first-year data of a three-year study, and the results are subject to errors which may occur due to variability inherent in the year of establishment. This is especially true for conclusions based on seed production. However, first-year data should be valid for such characteristics as flower color and seedling height. The analysis of seed production and seedling height is designed to measure the relative amount of general and specific combining ability of the cones involved. Reciprocals of the single crosses were evaluated for flower color, seedling height, and seed yield to check if reciprocal cross progeny give equal performance.