Agronomic Performance, Seed Quality and Seed Composition Evaluation in Soybean Inbred Lines Exposed to Environmental Stimuli.

Within-cultivar variation has been reported in a number of studies. This variation sometimes is attributed to genome fluidity, the capacity of the genome to re-organize when exposed to environmental stimuli. Honeycomb planting design has been used to enhance the expression of variation in soybean cultivars. In our research, aconitase isozyme allele-switching and agronomic performance variation in soybean cultivars ‘BSR 101’ (PI 548519), and ‘Jack’ (PI 540556) were detected. Seed source for the experiment was from honeycomb-grown, single-threshed plants that were exposed to natural hail in 2008, and a modified accelerated aging before planting in 2009. A study was initiated in 2011 to separate the effect of each stimulus in soybean cultivars ‘BSR 101’, and ‘Jack’. The objective of this study was to evaluate agronomic performance, seed quality and seed composition variability in progenies of ‘BSR 101’ and ‘Jack’ planted in honeycomb and conventional rows, and exposed to simulated hail. Preliminary results from 2013 and 2014 indicated that the effects of planting design and simulated hail were independent. Simulated hail alone had little effect on agronomic performance traits, seed quality and composition. However, results showed significant differences between honeycomb and row planting. Progenies from plants grown in a honeycomb design showed improved agronomic performance for most traits compared to row-planted progenies, but the response was cultivar dependent. Cultivar ‘BSR101’ expressed greater response than ‘Jack’. Our results suggested that honeycomb planting could be a viable tool to induce new genetic variation for future cultivar development.