Russian wildrye (Psathyrostachys juncea Fisch. 2n=2x=14, NsNs) is an important forage grass and a potentially useful germplasm in wheat improvement. A standard C-banding karyotype of Ps. juncea has been developed based on the C-bands of chromosomes in geographically diverse materials. Although there are C-banding polymorph isms, the seven pairs of chromosomes can be distinguished from each other according to their basic banding patterns. Based on C-banded karyotype, one deletion-t ranslocation heterozygote, four primary trisomies, one double-deletion trisomic, and two tertiary trisomies were identified. These cytogenetic stocks will be useful in genetic studies of Russian wildrye. Genetic variations in Russian wildrye were analyzed at chromosomal, protein and DNA levels using C-banding, isozymes, and randomly amplified polymorphic DNA (RAPD) techniques, respectively. Due to the self-incompatibility in Russia wild rye, a high level of genetic diversity existed both within and among accessions. In general, accessions originated from the same or neighboring geographical areas showed closer genetic relationships. The results of various approaches for genetic variation analysis suggest that there are tremendous genetic variations in the Russian wild rye germplasm for the effective improvement of this forage grass. Some molecular markers were isolated and characterized in Russian wildrye using RAPD and cloning techniques. These markers may be useful in gene mapping, species identification, studies of evolutionary relationships, and transferring useful genes into cereal crops.

A comparative index to digestible nutrients was established for Russian wildrye, crested wheatgrass, and intermediate wheatgrass seeded on foothill areas of Utah. The nutritive values of these grasses were compared by the lignin ratio method, the chlorophyllan ratio method, and the in vivo rumen bag process. Average digestion coefficients computed by the lignin ratio method for dry matter, ether extract, cellulose, and gross energy were highest for intermediate wheatgrass. Protein was more digestible for Russian wildrye. Digestible energy was adequate in all species to meet requirements for late lactation. Results from the chlorophyllan ratio method were excessively high and were not considered valid. Dry matter loss of Russian Wildrye was greater than losses from either of the wheatgrasses. Losses of dry matter due to 24-hour in vivo rumen fermentation and rinsing only of nylon bags were closely correlated.

Russian wildrye (Elymus junceus Fisch.) is a longlived perennial bunchgrass introduced to this continent from Siberia by the University of Saskatchewan in 1926 (Lawrence and Heinrichs, 1966). It is now widely distributed throughout the Northern Great Plains and Intermountain area (Figure 1). The species does well in the Northern Great Plains, but even though it is recommended for foothill ranges in the Intermountain area (Plummer, et aI, 1955), there are problems with establishment of Russian wildrye in the Intermountain area. This study was an attempt to fill in some of the gaps in the knowledge about establishment and survival of Russian wildrye on foothill ranges in Utah.