PARENT SESSION
Posters P6D Crop photosynthesis, agricultural biotechnology. Abstracts (742-753)

Effect of diffusible compounds from PGPR on soybean photosynthesis and growth under controlled environment conditions. Kyung Dong Lee^*,1, Elizabeth Gray², Alfred Souleimanov³, Xiaomin Zhou ⁴, Donald Smith⁵, ¹ Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Ste. Anne-de-Bellevue, QC, Canada² Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Ste. Anne-de-Bellevue, QC, Canada³ Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Ste. Anne-de-Bellevue, QC, Canada⁴ Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Ste. Anne-de-Bellevue, QC, Canada⁵ Department of Plant Science, McGill University, Macdonald Campus, 21111 Lakeshore Road, Ste. Anne-de-Bellevue, QC, Canada

ABSTRACT- The mechanisms by which plant growth promoting rhizobacteria (PGPR) stimulate plant growth are poorly understood. The objective of this study was to test for the presence and effect of diffusible plant growth promoting substances produced by PGPR isolated from the roots of field grown soybean plants in Eastern Canada. Materials were isolated by HPLC from a butanol extract of PGPR culture. Two soybean cultivars (OAC Oxford and Korada) were grown under controlled environment conditions. The material was applied as leaf sprays and root irrigations after diluting to 100, 1000 and 10000 HPLC microvolts (uV) when soybean plants were at the V1, V2 and V3 stages. Root irrigated 100, 1000 and 10000 uV treatments resulted in increased leaf areas, leaf greenness and dry weight for both soybean cultivars. However, the same response occurred only at 1000 uV for sprayed plants. In addition, photosynthetic rate was increased by irrigating soybean roots with 100 and 1000 uV treatments or spraying the 1000 uV treatment, compared to control plants. This study suggests that isolated bioactive activators from PGPR enhance soybean photosynthesis and growth and has substantial potential for commercial application.

KEY WORDS: soybean, Photosynthesis, PGPR