Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 7, 2005
Publication Date: N/A
Technical Abstract: Asian soybean rust (Phakopsora pachyrhizi Syd.), confirmed in the USA in November of 2004, can cause severe yield losses in many soybean producing areas of the world. Three single genes providing resistance to some isolates of P. pachyrhizi were separately backcrossed into soybean cultivar ‘Williams 82’ by R.L. Bernard (USDA) at the University of Illinois. However, the suitability of these lines for the current early soybean production system (ESPS) in the midsouthern USA has not been tested. The purpose of this research was to determine the suitability of the Williams 82 rust near-isogenic soybean lines for production in the midsouthern USA. Williams 82 near-isogenic soybean lines [L85-2378 (Rpp1), L86-1752 (Rpp2), and L87-0482 (Rpp4)], Williams 82, and AG 3905 were planted 19 April 2004 and 15 April 2005 at Stoneville, MS in 4-row yield plots with 91 cm row spacing. Data were taken for seed yield, maturity, plant height, seed weight, lodging, visual seed quality, percent impermeable seed coat, percent germination for both standard and accelerated aging germination tests, and incidence of Phomopsis longicolla Hobbs and rust. In 2004, in uninfested plots, all lines had similar maturities and plant heights. For seed yield, the three near-isogenic lines differed from each other, but did not differ from Williams 82. All lines, except L87-0482, yielded similarly to AG 3905, a cultivar currently grown in the ESPS, and showed good adaptation in the ESPS. Data for all the above traits in 2004 and 2005 will be presented and discussed in more detail, with appropriate conclusions provided.