New Peas Resist Fungal Foe
By Jan Suszkiw
August 8, 2008
Three spring pea germplasm lines
developed by Agricultural Research
Service (ARS) scientists are now available for breeding new commercial
cultivars that can withstand the fungus Fusarium solani.
F. solani causes Fusarium root rot, a disease affecting peas
worldwide, including in the Pacific Northwest and Northern Plains, where much
of America's crop is grown. Treating pea seeds with fungicide and sowing them
in well-drained soils can diminish the severity of the disease. Rotating peas
with non-host crops that aren't susceptible to the disease also helps. This
strategy works best when peas are naturally resistant.
To that end, ARS geneticist
Muehlbauer in 1994 crossed two germplasm linesX94P275 and
90-2131with "Dark Skin Perfection," a canning/freezing variety,
to produce a population of offspring plants from which the latest three
germplasm lines were ultimately selected and propagated for release earlier
this year. Muehlbauer made the crosses at the ARS
Legume Genetics Physiology Research Unit in Pullman, Wash., where he served
as research leader until retiring in 2006.
Three years of field trials indicate the linesdubbed RIL 846-34,
846-40 and 847-36offer some of the highest levels of fusarium root-rot
resistance to date. The pea lines also offer attractive green seed and other
desired agronomic traits to boot.
In 2004 field trials, RIL 846-34, 846-40 and 847-36 scored "7,"
"7" and "5," respectively, on a scale of zero to 100,
whereby zero signified complete resistance to Fusarium root rot and 100
indicated susceptibility to the disease. The scores for 90-2131 and Dark Skin
Perfection (a susceptible check) were 20 and 73, respectively.
Depending on the germplasm line, the pea plants flowered 57 or 61 days after
planting and yielded either smooth- or wrinkle-skinned seeds that weighed 17 to
24 grams per 100 seeds.
Coyne, with the ARS
Germplasm Introduction and Testing Research Station in Pullman, is handling
seed requests. She expects pea breeders will cross the lines with their own
germplasm material to develop new, high-yielding commercial cultivars.
ARS is a scientific research agency of the U.S. Department of Agriculture.