Germination characteristics among different sheepgrass (Leymus chinensis) germplasm during the seed development and after-ripening stages

Abstract

Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an important forage grass in the Eurasian steppe. However, little information is available concerning its seed morphological features and germination characteristics during seed development and after-ripening among different germplasm. To clarify the appropriate seed harvest time and the effects of germplasm, seed development and after-ripening on seed germination, 20 germplasm of sheepgrass were selected. Moreover, the seed morphological and physical changes as well as the seed germination and dormancy characteristics of sheepgrass during seed development stages were analyzed using a seven—d gradient of day after pollination (DAP). The results indicated that the seed water content decreased significantly during 35–42 DAP and that the highest seed germination rate of most germplasm was observed at 35–42 DAP. Thus, 35–42 DAP may be the best time to harvest sheepgrass to obtain the maximum seed germination rate and avoid seed shattering. Furthermore, our results indicated that there were six types of germination patterns, including germplasm with increasing germination rates in the developing seed, such as S19 and S13, and germplasm that maintained a consistently low germination rate, such as S10. Moreover, we compared the seed germination rate of eight germplasm during seed development in both 2016 and 2017, and the results indicated that the seed germination patterns of the eight germplasm were highly consistent between the two consecutive years, suggesting that germplasm rather than year is the major factor in determining germination during seed development. The effect of after-ripening on seed germination was different among the germplasm where four types of germination patterns were revealed for 10 germplasm and resulted in various dormancy features. A two-factor ANOVA analysis suggested that the germplasm of the sheepgrass has a large influence on seed germination, whether during seed development or after-ripening. Thus, these findings lay the foundation for future studies on seed dormancy and germination and may guide the breeding of new cultivars of sheepgrass with better germination performance.

Breaking Seed Dormancy during Dry Storage: A Useful Tool or Major Problem for Successful Restoration via Direct Seeding?

“…Afterripening has been reported in seeds that remain on dead mother plants in the field [59] and in those stored in closed containers at room temperature [59,63], in paper bags at room temperature [64,65], dry at ambient room temperature and relative humidity (RH) [66], at 30% RH at room temperature [67] and in sealed Petri dishes at 20 • C [68]. Also, afterripening is known to occur in seeds stored dry at low temperatures, for example, seeds of Hordeum vulgare L. afterripened at 8 • C [69], Berberis spp.…”

Themeda Triandra as a Perennial Seed Crop in South-Eastern Australia: What Are the Agronomic Possibilities and Constraints, and Future Research Needs?

“…As such, one of the most promising dormancy-breaking techniques for T. triandra is dry storage of seed over an extended period following harvest (>6 months). Known as after-ripening, this process has been reported in seeds of a variety of species that experience a range of conditions, including un-shed seed remaining in the field on their mother plant (Baskin & Baskin, 1977), seed stored in closed containers at room temperature (Baskin & Baskin, 1977, seed stored in paper bags at room temperature (Moyo et al, 2009;Ralowicz & Mancino, 1992), seed at room temperature with varying levels of humidity (Kundu & Chaturvedi, 2019;Yang et al, 2019), and seed in sealed petri dishes at 20°C (Karimmojeni et al, 2011). The mechanism for this dormancy breakdown is not fully understood, although it is assumed that the glumes and/or lemma and palea control dormancy by containing inhibitory substances, causing mechanical restriction during germination, reducing oxygen transport to the embryo and reducing imbibition (Hagon, 1976).…”

Exogenous Spermidine Priming Mitigates the Osmotic Damage in Germinating Seeds of Leymus chinensis Under Salt-Alkali Stress

“…Tzvel., one of the most important grassland plants in the Songnen Plain, is a perennial rhizomatous species of the Poaceae family containing high levels of proteins, mineral nutrients, and carbohydrates (Lin et al, 2016). Studies have shown that L. chinensis has a strong capacity for asexual reproduction and resistance to environmental stresses (Yang et al, 2019). The mature seedlings of L. chinensis have a strong tolerance to saltalkali stress and are the most promising gramineous plant for the rehabilitation of grassland vegetation in soils with salinizationalkalization (Li et al, 2018).…”