California Early Red onions, one of more than 70
short-day varieties that scientists regenerated because they were in danger of
being lost from the National Plant Germplasm Collection. (Image courtesy
Christopher Cramer, New Mexico State University, Las Cruces.)
Short-Day Onions Saved for the Long Haul
By Luis Pons
August 30, 2005
More than 70 varieties of short-day
onions will be around for a long time, thanks to scientists with the
Agricultural Research Service (ARS) and
New Mexico State University (NMSU).
Robertson in the ARS Plant Genetic Resources Unit (PGRU)
at Geneva, N.Y., and onion breeder Christopher Cramer at NMSU's
Department of Agronomy and Horticulture
led work to regenerate 75 accessions of these onions that were in danger of
being lost from the National Plant Germplasm System (NPGS).
As part of NPGS, ARS' Geneva laboratory preserves material from many crop
plants, including onions, to ensure a constant supply of them. It safeguards
more than 1,100 onion samples from 63 countries.
PGRU was on the brink of running out of many short-day onion samples because
Geneva's long day lengths in summer hampered efforts to regenerate seed.
Short-day onions bulb and flower only when day lengths are shorter than
approximately 12 hours. Summer day lengths in Geneva reach 14 hours during the
onions' critical growth periods.
Three years ago, Robertson acted to save these accessions by contacting
Cramer to propose growing the onions on NMSU's Las Cruces campus, where key day
lengths are shorter than in Geneva.
The seeds of 54 saved accessions have been sent to PGRU to be reincorporated
into the collection and made available for distribution. Seventeen varieties
that produced less seed than desired were retained by NMSU in order to produce
additional seed from the same plants.
According to Robertson, this cooperative project has been extended for a
year to provide for routine regeneration of short-day onions for the Geneva
The National Plant Germplasm System is a cooperative state, federal and
private effort to preserve the genetic diversity of plants. Part of the
ARS-administered National Genetic Resources Program (NGRP), it helps offset genetic uniformity
resulting from intensive agriculture that increases crop vulnerability to pests
ARS is the U.S. Department of
Agriculture's chief scientific research agency.