Interaction of Seedling-Pathogens with Physiological Seed Quality Affecting Soybean Emergence and Seedling Growth

Seed vigor is a complex trait which refers the quick and uniform germination of seeds in the field.It can be highly affected by the genetic background of the seed, the environment where the seeds are grown, and storage conditions (Yang, X. B. 1999).Besides, seeds affected by quality parameters may respond differently to seedling pathogens in the soil; these responses are likely to differ according to environmental conditions.The main objective of the study was to evaluate the relationship between soybean quality and the effects of specific soil-borne pathogens on soybean emergence and seedling growth, with a specific focus on phenotyping early-stage roots.Seed lots with different levels of seed quality, represents a range of seed vigor with the same genetic background, were created by accelerated-aging (aa) treatments.The effect of aa on seed performance was tested in growth chambers with and without infested soil at 20 °C and 25 °C.A remarkable emergence reduction (65-55%) was observed in the aged-seed.Synergistic effects between seed aging and Rhizoctonia solani infestation was observed on root biomass (root dry weight) and the numbers of root tips, forks, and crossings (p<0.05).Besides, some parameters such as plant length and fresh weight, fresh root weight, root length, volume, and surface area were significantly affected by both seed quality and fungal inoculum.The results obtained from the study is expected to contribute on determining the impact of environmental conditions and stress factors on the epidemiology of soilborne pathogens.On the other hand, we expect that the results will shed light on developing new strategies for effective disease management.