|Thompson, Jeffrey - PIONEER, HAMEL, IL|
|Amdor, Paul - DECEASED (ARS/URBANA)|
Submitted to: Germplasm Release
Publication Type: Germplasm Release
Publication Acceptance Date: September 9, 1997
Publication Date: N/A
Interpretive Summary: This is a Germplasm Release, no Interpretative Summary Required.
Technical Abstract: Only four ancestral lines account for nearly 50% of all the genes in soybean varieties currently grown in the U.S. Expanding the diversity of the genetic base of U.S. soybean production could have both short- and long-term positive effects on yield improvement. We have developed and released two experimental lines that can be used for that purpose. LG90-2550 is an F6 selection from LG82-8224 x LG82-8195. LG82-8224 and LG82-8195 are F4 selections from the cross of PI 68658 x Lawrence. LG90-2550 is resistant to race 7 of P. sojae and has a low level of iron chlorosis. LG90-2550 is in maturity group (MG) III with semi-determinate stems (presumably Dt2Dt2) and is comparable in yield to current MG III cultivars. LG91-7350R is an F10 reselection from LG91-7350. LG91-7350 is an F6 selection from BSR 101 x LG82-8379. LG82-8379 is an F4 selection from PI 68508 x FC 04007B. LG91-7350 is heterogeneous, most notable for reaction to race 7 of P. sojae and pubescence color. LG91-7350R is high-yielding, uniform for pubescence color, and resistant to races 1, 3, 7, and 10 of P. sojae. LG91-7350R is in MG IV with indeterminate stems and is comparable in yield to current MG IV cultivars. The three exotic parental lines (FC 04007B, PI 68508, PI 68658) are yellow-seeded, grain-type soybeans in MG II or III that have been in the USDA Soybean Germplasm Collection for more than 70 years. These introductions do not occur in the pedigrees of any released cultivars or germplasm. Research employing RAPD markers and cluster analysis to evaluate genetic diversity has shown that the introductions used in these crosses are genetically distinct from the current U.S. soybean genetic base and that diversity has been preserved after selection for high yield in the progeny.