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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVEMENT OF HARD RED SPRING AND DURUM WHEAT FOR DISEASE RESISTANCE AND QUALITY USING GENETICS AND GENOMICS

Location: Cereal Crops Research

Title: Marker-assisted Characterization of Durum Wheat Langdon-Golden Ball Disomic Substitution Lines

Authors
item Xu, Steven
item Chu, C -
item Chao, Shiaoman
item Klindworth, Daryl
item Faris, Justin
item Elias, E -

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2010
Publication Date: February 7, 2010
Citation: Xu, S.S., Chu, C.G., Chao, S., Klindworth, D.L., Faris, J.D., Elias, E.M. 2010. Marker-assisted Characterization of Durum Wheat Langdon-Golden Ball Disomic Substitution Lines. Theoretical and Applied Genetics.120:1575-1585

Interpretive Summary: Durum wheat variety ‘Golden Ball’ (GB) has solid stem compared with most of durum and bread wheat varieties with hollow stem. Although solid straw is often considered an unwanted slowly-degradable waste product, it is an excellent source of resistance to wheat stem sawfly and a potential source of bio-feed for producing bio-fuel. In an effort to investigate the genetic control of solid stem, Dr. Leonard Joppa (ARS retired) previously used GB as the chromosome donor and hollow-stem durum variety ‘Langdon’ (LDN) as the chromosome recipient to develop a set of 14 inter-variety chromosome substitution lines where a pair of chromosomes in LDN was substituted by a pair of corresponding chromosomes of GB. These substitution lines are useful tools for evaluating the effect of stem solidness on grain and biomass yield and for locating both major and minor genes governing stem solidness and other traits. The objective of this study was to characterize the 14 substitution lines using molecular markers and to evaluate the stem solidness of the substitutions. For molecular marker analysis, we first used the 35 molecular markers with known chromosomal locations to confirm the chromosome assignments of the 14 substitution lines and then used a new and high-efficient marker technique to evaluate genome compositions of the 14 substitution lines. The results showed that the 14 substitution lines all have correct chromosome assignments, but they have genetic backgrounds that are not highly consistent with their recipient parent LDN. Evaluation of stem-solidness in the substitution lines indicated that the chromosome 3B substitution line had stem-solidness scores significantly higher than those of LDN and the other substitution lines, but significantly less than that of GB, suggesting that a major gene on chromosome 3B controls stem solidness in GB. This research provides useful information for the utilization of GB and LDN-GB DS lines for genetic and genomic studies of tetraploid wheat and for the improvement of sawfly resistance in durum and bread wheat.

Technical Abstract: The durum wheat cultivar ‘Golden Ball’ (GB) has superior solid stem, which is a source of resistance to wheat sawfly and also a potential source of biofeed for producing biofuel. Dr. Leonard Joppa previously used GB as the chromosome donor and Langdon (LDN) durum as the recipient to develop a complete set of 14 LDN-GB disomic substitution (DS) lines. The objective of this study was to characterize the 14 LDN-GB DS lines using molecular markers and to evaluate the stem solidness of the substitutions. SSR markers were used to confirm the chromosome assignments of the 14 LDN-GB DS lines. Genome-wide scans using TRAP markers revealed a total of 359 polymorphic fragments. Among them, 134 (37.3%), 185 (51.5%), and 10 (2.8%) were derived from LDN, GB, and Chinese Spring (CS), respectively, and 14 (3.9%) fragments that were only present in some of the LDN-GB DS lines were classified as “novel” markers. Only 200 (62.7%) of 319 polymorphic fragments derived from LDN and GB were chromosome-specific markers, whereas 116 (36.4%) simultaneously appeared on two or more chromosomes. These findings indicate that the set of LDN-GB DS lines have genetic backgrounds that are not highly consistent with LDN. Evaluation of stem-solidness in LDN-GB DS lines indicated that the substitution line LDN-GB(3B) had stem-solidness scores significantly higher than those of LDN and the other substitution lines, but significantly less than that of GB, suggesting that a major gene on chromosome 3B controls stem-solidness in GB. This research provides useful information for the utilization of GB and LDN-GB DS lines for genetic and genomic studies of tetraploid wheat and for the improvement of sawfly resistance in durum and bread wheat.

Last Modified: 9/1/2014