|Daughtry, Lee - MS DEPT OF AGRICULTURE|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2004
Publication Date: August 10, 2004
Citation: Smith, J.R., Fritschi, F.B., Ray, J.D., Mengistu, A., Daughtry, L., Paris, R.L., Nelson, R.L. 2004. Heat stress in the early soybean production system [abstract]. 10th Biennial Conference of the Cellular and Molecular Biology of the Soybean Program. p. 38. Technical Abstract: Average yields from conventional Midsouthern soybean production of the 1970s ranged from 1344 to 1478 kg ha-1 in Mississippi. Seed quality was excellent. During the 1980s and 1990s, new production technologies (stale seedbed, improved irrigation efficiencies, earlier planting, glyphosate-resistant varieties, and early-maturing varieties) were utilized to improve soybean seed yield such that in 2003, Mississippi produced a record 2621 kg ha-1 seed yield. This yield exceeded the U.S. average (2251 kg ha-1) for the first time in history. However, the quality of seed produced by the new system (Early Soybean Production System- ESPS) is typically poor. Seed may have poor germination, be smaller and wrinkled, have a higher incidence of diseases, and have an impermeable seed coat. The reduction in seed quality observed in the ESPS is likely affected by the fact that seed-filling period, seed maturation, and harvest all occur during periods (July-September) of high heat and humidity. Efforts are underway to identify soybean genotypes that produce high yield and high quality seed under high-heat conditions. Seed quality data will be presented for selected plant introductions grown and evaluated in the ESPS. Also, preliminary growth, physiological, and proteomic data will be presented for heat-affected isogenic lines subjected to differential heat treatments in growth chamber and greenhouse experiments.