Interspecific hybridization between Hordeum vulgare (L.) and H. bulbosum (L.) and their backcross progenies.

P. Bregitzer, A. Hang, P. M. Hayes, and S. D. Kindler
USDA-ARS, Aberdeen, 1D 83210
USDA-ARS, Stillwater, OK 74075, and
Department of Crop and Soil Science
Oregon State University
Corvalis, OR 97331, U.S.A.

The Hordeum bulbosum-mediated doubled haploid production method used at Oregon State University (Hayes and Chen, 1989) has produced several putative hybrids between H. bulbosum. Clones of four putative hybrids were sent to Aberdeen. These plants possessed an upright growth habit, were perennial, and had spike morphologies that resembled the H. bulbosum parent. Two clones, VB 3 and VB 4, were diploid and completely sterile. Two clones were partially fertile and occasionally self-fertile (VB 2), and one was tetraploid (VB 1). Meiotic analysis of VB 2 showed that chromosome pairing ranged from two to seven bivalents, indicating that recombination between the two to seven bivalents. Approximately 20 backcross progeny have been obtained from VB 1 and VB 2 using 'Bowman', 'Excel', 'Bearpaw', and 'Hector'. All recovered plants have a spring growth habit and appear to be vulgare-like.

VB 1 and VB 2 have been determined to possess resistance to damage caused by Russian Wheat Aphid (RWA) feeding in tests done at the Plant Science Research Laboratory in Stillwater, Oklahoma. Seed from two selfed progeny from VB 2 and two VB 1 backcross progeny-are currently being eval uated for resi stance tn RWA.

The pedigrees of VB 1 and VB 2 are uncertain. However~ because all plants recovered from the hybrids have had a spring growth habit, it is probable that they originated from a spring × winter crossing program at Oregon State. The spring cultivars that are likely parents are 'Azure' and an advanced breeding line developed at Aberdeen, 79Abl3597; potential winter parents are three advanced breeding lines developed at Oregon State. These potential H. vulgare parents have been determined to be susceptible to RWA damage. The source of RWA resistance in the hybrids therefore appears to have come from one or more of the four diploid H. bulbosum clones in use at Oregon State: 2920-4, 2921-1, CSU-2, and CSU-12. These clones have not yet been tested for RWA resistance. Isozyme characterization of these putative parents will be used to help determine the likely pedigrees of VB 1 and VB 2, and attempts will be made to generate additional hybrids.

References:

Hayes, P. M., and F. W. Chen. 1989. Genotypic variation for Hordeum bulbosum L. - mediated doubled haploid production in winter and facultative barley. Crop Sci. 29:1184-1188.

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