Has Selection for Grain Yield Altered Intermediate Wheatgrass?

Abstract

Perennial grains are demonstrating a greater probability of occupying land currently dedicated to other agricultural production. Arable land that is currently in use for forage or annual crop production becomes utilized. Breeding materials for the introduction of perennial grains directly into the human food chain has required utilizing existing plant materials in the domestication of species or manufacturing diverse crosses to introduce perenniality into existing crops. In the domestication of intermediate wheatgrass (Thinopyrum intermedium (Host), Barkworth and Dewey), existing forage cultivars or plant accessions were used to develop populations selected for grain production. A comparison of Cycle 3 materials from The Land Institute (TLI), Salina, KS, USA to USDA-Germplasm Resources Information Network (GRIN) accessions took place under space-planted field conditions at Carman, MB, Canada from 2011 to 2014. One hundred plants (75 TLI and 25 GRIN identified in May 2012) were followed through three seed harvests cycles with phenological, morphological and agronomic traits measured throughout. Selection for seed productivity (TLI materials) reduced the importance of biomass plant −1 on seed yield plant −1 , leading to an increase in harvest index. Principal component analysis demonstrated the separation of the germplasm sources and the differential impact of years on the performance of all accessions. Path coefficient analysis also indicated that plant biomass production was of less importance on seed yield plant −1 in the TLI materials. Analysis removing area plant −1 as a factor increased both the importance of biomass and heads on seed yield cm −2 in the TLI materials, especially in the first two seed production years. Plant differences due to selection appear to have reduced overall plant area and increased harvest index in the TLI materials, indicating progress for grain yield under selection. However, a greater understanding of the dynamics within a seed production field is needed to provide insight into the development of more effective selection criteria for long-term field level production.

Floret site utilization and reproductive tiller number are primary components of grain yield in intermediate wheatgrass spaced plants

“…The SEM model supports this finding, wherein reproductive tiller number was the primary driver of yield measured in this way in all environments (Figure 4; Supplemental Tables S8–S11). Cattani and Asselin (2018) also demonstrated the importance of the contribution of reproductive tillers per unit area and plant biomass to IWG yield in spaced plants. In sward environments, however, IWG has a tendency to produce nonreproductive, or “culmed,” tillers that bear no seed head but grow to similar heights (Hunter et al., 2020).…”

Comparative Analysis of Early Life Stage Traits in Annual and Perennial Phaseolus Crops and Their Wild Relatives

“…Seed size alone may be less reflective of whole-plant reproductive allocation (Vico et al, 2016) and more so of a tolerance-fecundity tradeoff, where larger seeds are produced in fewer numbers but have greater competitive ability in stressful conditions (Muller-Landau, 2010). Nevertheless, the perennial grain crop Thinopyrum intermedium showed a positive relationship of total biomass and single seed mass with total reproductive yield across three years of growth, suggesting that these traits are positively correlated in some perennial species (Cattani and Asselin, 2018; also see Kleyer et al, 2019). Lastly, significant positive associations between all dry biomass traits do not support aboveground-belowground tradeoffs; rather, the data suggest that larger plants require greater resource acquisition with proportionally larger roots.…”

Process-based analysis of Thinopyrum intermedium phenological development highlights the importance of dual induction for reproductive growth and agronomic performance

“…Intermediate wheatgrass can support the transition to agroecological systems because this perennial crop produces forage and grain for several years with minimal soil disturbance and associated environmental issues (Duchene et al, 2019;Ryan et al, 2018). Featuring large and deep roots, year-round soil cover, increased resource use efficiency and an extended growing season (Cattani and Asselin, 2018a;DeHaan, 2015;Glover et al, 2010;Sprunger et al, 2018), the 'perennialization' of cropping systems would be one cornerstone of sustainable agriculture (Crews, 2016).…”