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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #190957
Title: MAPPING OF QUANTITATIVE TRAIT LOCI (QTL) FOR WINTER HARDINESS IN PERENNIAL RYEGRASS (LOLIUM PERENNE L.)

Author
item XIONG, Y - IOWA STATE UNIVERSITY
item FEI, S - IOWA STATE UNIVERSITY
item BRUMMER, E - IOWA STATE UNIVERSITY
item ARORA, R - IOWA STATE UNIVERSITY
item Barker, Reed
item JUNG, G - UNIVERSITY OF WISCONSIN
item Warnke, Scott

Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/2004
Publication Date: 10/31/2004
Citation: Xiong, Y., Fei, S., Brummer, E.C., Arora, R., Barker, R.E., Jung, G., Warnke, S.E. 2004. Mapping of quantitative trait loci (qtl) for winter hardiness in perennial ryegrass (lolium perenne l.). American Society of Agronomy Abstracts. Paper No. 4843.

Interpretive Summary: Winter hardiness is a complex trait and lack of winter hardiness is a major problem that affects the distribution of perennial ryegrass world-wide. Perhaps winter hardiness in perennial ryegrass could be predicted by its component trait, freezing tolerance (FT) and possibly another component trait, fall growth (FG). A segregating population of 170 progenies derived from a cross between a winter hardy “Manhattan” perennial ryegrass and a winter sensitive “Floregon” annual ryegrass was utilized to identify and compare quantitative trait loci (QTL) associated with winter survival (WS), FT and FG. There was a positive correlation between FT and WS. Four QTLs each on linkage group1, 3, 4 and 5 (LG1, 3, 4 and 5) were identified to confer winter survival and freezing tolerance, respectively. Two QTLs each for WS and FT overlapped and were mapped to similar intervals as FG. Two QTLs on LG1 and 4 were found to be strongly associated with fall growth. These genetic locations provide genetic locations where possible DNA differences in winter hardiness might be found, and these differential DNA sequences would help in ryegrass breeding programs.

Technical Abstract: Winter hardiness is a complex trait and lack of winter hardiness is a major problem that affects the distribution of perennial ryegrass. Winter hardiness in perennial ryegrass could be predicted by its component trait, freezing tolerance (FT) and possibly another component trait, fall growth (FG). A segregating population of 170 progenies derived from a cross between a winter hardy “Manhattan” perennial ryegrass and a winter sensitive “Floregon” annual ryegrass was utilized to identify and compare quantitative trait loci (QTL) associated with winter survival (WS), FT and FG. The genetic map previously developed from 235 loci had a total length of 607.9 cM with a density of one marker every 2.6 cM. Freezing tolerance was evaluated as LT50 value by measuring ion leakage. Fall growth was measured as vertical regrowth following the last mowing in the fall. Winter survival was scored in early spring by a scale of 0-5 with 0 being completely dead and 5 being no injury. There was a positive correlation between FT and WS. Four QTLs each on linkage group1, 3, 4 and 5 (LG1, 3, 4 and 5) were identified to confer winter survival and freezing tolerance, respectively. Two QTLs each for WS and FT overlapped and were mapped to similar intervals as FG. Two QTLs on LG1 and 4 were found to be strongly associated with fall growth.