Nebraska

Utilization of Hordeum spontaneum Accessions in the Nebraska Winter Barley Breeding Program

B. T. Campbell and P. S. Baenziger

University of Nebraska-Lincoln

New sources of genetic variability continue to be of utmost interest to plant breeders of all crops. For winter hardiness, we have exploited most of the genetic variation in the adapted gene pool. After discussions with Professor Nevo of Israel, we tested a number of Hordeum spontaneum lines from his collection. The preliminary results indicated most H spontaneum lines died during our winter, but a few survived. In 1999, we planted 960 H. spontaneum accessions from the National Small Grains Collection in Aberdeen, ID, in unreplicated hill plots at Lincoln, NE. The 1999-2000 winter was exceptionally mild, but still caused winter killing. Of these 960 accessions, 389 survived the winter and were harvested in July 2000. Fifty-six of the 389 harvested accessions appeared phenotypically desirable (well tillered, vigorous plant type) and were subsequently planted in our greenhouse crossing-block for spring 2001. Our objective is to hybridize several of the selected accessions with advanced breeding lines and standard Nebraska winter, feed barley cultivars. F₁ and BCF₁ seed from these crosses will be increased in the greenhouse, with F₂ and BCF₂ bulks evaluated in a standard field trial the following year to identify superior populations. We hope that H. spontaneum will add new genes for winter survival and stress tolerance to our cultivated winter barley germplasm base.