HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bregitzer, P. Articles by Manoharan, M. Search for Related Content PubMed Articles by Bregitzer, P. Articles by Manoharan, M. Agricola Articles by Bregitzer, P. Articles by Manoharan, M. Related Collections Other Grain Crops Crop Genetics

A Single Backcross Effectively Eliminates Agronomic and Quality Alterations Caused by Somaclonal Variation in Transgenic Barley

^a USDA–ARS National Small Grains Germplasm Research Facility, 1691 S. 2700 W., Aberdeen, ID 83210
^b USDA–ARS, Northern Crop Science Lab., 1307 N. 18th St., Fargo, ND 58105
^c Dep. of Plant Pathology, Walster Hall, North Dakota State Univ., Fargo, ND 58105
^d Dep. of Plant Sciences, Loftsgard Hall, North Dakota State Univ., Fargo, ND 58105
^e Dep. of Agriculture, Univ. of Arkansas at Pine Bluff, AR 71601

^* Corresponding author (phil.bregitzer{at}ars.usda.gov).

Transgenic crops have proven commercial utility but are created using processes known to produce undesirable variability known as somaclonal variation. This reduces the utility of transgenic germplasm to the plant breeder and complicates assessments of transgene-encoded phenotypes. Backcrossing transgenes into a wild-type genome is one solution, but producing near-isogenic lines requires a lengthy and resource-intensive process of multiple crosses. However, an abbreviated breeding scheme involving a single backcross to the wild-type parent used to produce a transgenic line, which would replace 75% of the variant alleles, should produce transgenic lines with improved performance. Comparisons were made of ‘Conlon’ barley (Hordeum vulgare L.), primary transgenic lines derived from Conlon, and lines derived from single backcrosses of primary transgenic lines to Conlon. The primary transgenic lines were different from Conlon for many agronomic and malting characteristics. Most of the backcross-derived lines did not differ significantly from Conlon for most agronomic characteristics. The backcross-derived lines were also similar to Conlon for malting quality traits but showed more differences than for agronomic characteristics. Differences between lines encoding TRI101 versus lines encoding PDR5 suggested that PDR5 insertion or expression may have affected malting quality. It is concluded that a single backcross is an effective, rapid, and inexpensive method for creating superior transgenic lines.

Abbreviations: BC, backcross • FAN, free amino nitrogen • PCR, polymerase chain reaction

Received for publication June 29, 2007.