Selection of a perennial grain for seed productivity across years: Intermediate wheatgrass as a test species.

Abstract

Development of perennial grains is being promoted to aid in moving agriculture towards sustainable production. How long does it take to identify perennial yielding ability? Intermediate wheatgrass (Thinopyrum intermedium) nurseries were transplanted in 2011 (4,500 plants) and 2012 (1,000 plants) at Carman, Manitoba. Productive, healthy plants were harvested on a yearly basis. Intolerance to late frosts after spring regrowth initiation in 2012 (approximately 55% of the plants) and in 2014 (the entire 2012 nursery) led to these plants not being harvested. Mean yield plant-1 was 37.25, 66.70 and 57.81 g for the 2102, 2013 and 2014 overall harvests, respectively. Individual plants showed divergent seed yielding patterns across years, especially with respect to the third harvest year. A number of plants were identified that had consistent relative seed yields over the three years of harvest for the 2011 nursery. Linear regression indicated that the first year of seed production was a poor indicator of relative yield potential over all three years (R 2 = 0.238) amongst the highest overall yielding plants, with 2013 and 2014 having greater predictability. Variability in yield in the third reproductive year indicated that the third year is required to identify highly productive individuals for three consecutive seed harvests.

Has Selection for Grain Yield Altered Intermediate Wheatgrass?

“…Climate data were collected at the Carman Research Station and compiled on a daily basis for the cropping years studied (2011)(2012)(2013)(2014). This data has been previously reported [1].…”

“…Flowering and harvest timings were later by the third reproductive year. Mean Yield was highest in 2013 and lowest in 2014 similar to data previously reported [1]. Yield and SYA were also highest in 2013 and were positively correlated with r values of r = 0.74 in 2012, r = 0.70 in 2013 and r = 0.88 in 2014 (p < 0.01 for all years).…”

“…Cold temperatures in April 2012 led to the removal of approximately 60% of the materials from the overall study [1]. Accession or breeding line was not a consistent factor in identifying damaged plants although TLI lines were generally more variable.…”

“…Perennial grains have received greater attention in the past decade due in part to their potential to be productive over a number of years [1] and potential positive impacts on soils [2]. Potential environmental benefits of perennialized cropping systems include higher carbon storage [3,4], greater water use efficiency [5], better nutrient management and greater soil protection than annual crops [6].…”

Comparative analysis of seed size, germination, and vegetative allocation in annual and herbaceous perennial crops and their wild relatives inLupinusandPhaseolus(Fabaceae)

“…In the perennial oilseed candidate Physaria mendocina (Brassicaceae), selection for seed yield was associated with lower root allocation and seed production in subsequent years compared to wild forms (González-Paleo et al, 2016; Pastor-Pastor et al, 2018). Similarly, in perennial wheat relatives (Poaceae), high seed production in year one was associated with lower yields and lower survival in subsequent years (Vico et al, 2016; Cattani, 2017). Nevertheless, concomitant perennation and high seed yield has been observed in multiple perennial cereals (Sacks et al, 2007; Jaikumar et al, 2012; Culman et al, 2013; Huang et al, 2018), suggesting that this combination is not biologically incompatible and may be specifically selected for in breeding.…”