Wednesday, November 15, 2006
274-4
Evaluation of Soybean Plant Introductions for Tolerance to Soil-waterlogging.
James Shannon1, Robert McGraw2, David Sleper3, Jeong Lee3, and Henry Nguyen4. (1) Univ. of Missouri, PO Box 160, PO Box 160, Portageville, MO 63873, United States of America, (2) University of Missouri, Columbia, MO 65211, (3) Dept. of Agronomy Univ. of Missouri, 271F Life Sciences Center, 271F Life Sciences Center, Columbia, MO 65211-7310, United States of America, (4) Univ. of Missouri-Columbia, Division of Plant Sciences, 1-41 Agriculture Building, Columbia, MO 65211
Excess rain and over-irrigation on poorly drained fields or low lying areas can result in flooding and soil waterlogging. Soybeans may never fully recover from flooding injury. Soybean plant introductions (PIs) from the USDA world collection could offer higher levels of soil water logging tolerance than exists in current soybean cultivars. In 2005, 262 group III and IV (PIs) collected from both wet and dry areas of the world were planted in three replicate hills near New Franklin, MO in specially constructed channels where the length and amount of flooding can be precisely controlled by pumping water on and off of plots as necessary. A water-logging tolerant soybean, PI 408105A, identified in earlier studies was also planted among these plant introductions for comparative purposes. Plots were flooded about two inches deep at flowering until plants began to yellow, wilt and die (about 14 d). Plots were then drained, soil allowed to dry and PIs were rated for injury on a 1 (no injury) to 5 (all plants dead) scale after a two week recovery period. Twenty (20) soybean PIs had flood tolerance scores of 1.0 to 2.0 which showed little injury to severe flooding compared to a score of 2.6 or moderate injury for PI 408105A. Seventy-eight (78) PI lines had scores of 2.3 to 3.0 and were moderately tolerant – moderately sensitive to excess water; and 164 PIs were severely injured from severe soil water-logging with scores of 3.3 – 5.0. Data combined from New Franklin in 2005 and in 2006 from New Franklin and Portageville , MO will identify those PIs which show the best flood tolerance over years and locations.