Caryopsis Weight and Planting Depth of Blue Grama I. Morphology, Emergence, and Seedling Growth

Abstract

Blue grama [Bouteloua grads (H.B.K.) Lag. ex Steud.] has been diicult to establish from seed on disturbed areas of the Central Plains. The objective of this study was to investigate the relationship of caryopsis weight, planting depth, and genetic variability on seedling emergence of blue grama. Two experiments were conducted in the greenhouse under favorable moisture conditions with 3 accessions and various combinations of caryopsis weight and planting depth. Measurements included rate of germination and emergence as an index, percentage emergence, shoot length, shoot weight, seminal root length, coleoptile length, subcoleoptile internode length and weight, adventitious root weight, and longest adventitious root length. The length of the subcoleoptile internode increased in response to greater planting depth but weight per unit length deereased. If this indicates a decrease in internode diameter it could decrease the rate of water transport through the internode. Deep plantings were not advantageous to emergence or seedling growth under favorable soil moisture conditions and caused a delay in emergence and decreased percentage emergence, shoot weight, and adventitious root weight. High crryopsisweight was associated with an increase in emergence, weight per unit length of the subcoleoptile internode, coleoptile length, shoot weight, and adventitious root weight. Therefore, high caryopsis weight is advantageous in the deep plnnting of blue grama seeds and allows seeds to be planted deeper to take advantage of moisture for germination and emergence.

Seed Yield Variation in Blue Grama and Little Bluestem Plant Collections in Southern Manitoba, Canada

“…In comparison, Roos and Quinn (1977) obtained 100‐caryopses weights ranging from 74.5 to 98.0 mg among plants from two young (2–3 yr) and two old (35–40 yr) little bluestem populations in New Jersey. The large amount of variation in caryopsis weight seen in this study indicates that selection for this trait can be effective with selection within or among plant collections, as indicated earlier by Wilson et al (1981) Native grasses can benefit from larger caryopses because this trait enhances seedling emergence and stand establishment (Carren et al, 1987a, 1987b).…”

Geographic patterns of simulated establishment of two Bouteloua species: implications for distributions of dominants and ecotones

“…These experimental findings were used previously to determine establishment criteria for B. gracilis to be used in simulation modeling (Table 3; Lauenroth et al 1994). Seeds were simulated to germinate in the top soil layer since experimental work with B. gracilis indicates high germination of seeds in the top soil layer (1 -2 cm), decreasing with depth (Carren et al 1987). There are two differences between the germination and establishment criteria for B. gracilis used in the current study and the criteria developed previously.…”

Production characteristics of the mixed prairie: constraints and potential

“…Heavier seed classes had greater emergence from planting depths greater than 3.0 cm (Carren et al 1987b) and were correlated to greater shoot biomass and adventitious root weight. Under soil moisture stress, high seed weight was required for emergence from a depth of 2.0 cm (Carren et al I987a).…”

“…Blue grama grass exhibits variation in seed weight (Carren et al 1987b), water uptake of the seminal root system, and seedling shoot biomass (Nason et al 1987). Heavier seed classes had greater emergence from planting depths greater than 3.0 cm (Carren et al 1987b) and were correlated to greater shoot biomass and adventitious root weight.…”