Seed traits and germination characteristics of sheepgrass (Leymus chinensis)

Abstract

Seed traits including seed size, seed color, seed yield, and seed germination characteristics are valuable factors in sheepgrass cultivation and application. The seed characteristics of sheepgrass vary among genotypes and environmental factors. Seed-setting rate and floret number can decide the seed yield of sheepgrass, and the correlation between seed size and thousand grain weight is significant (P < 0.01). Seed shattering before seed harvest can greatly reduce the seed yield. The shattering of sheepgrass seed is mainly caused by occurrence of the abscission layer on the Z-shaped rachilla and is also affected by the genotype and the environment. Multiple factors exert a significant effect on seed germination of sheepgrass, including genotype, plant hormones, the lemma restriction, and temperature. Under the variable temperature of 28 °C (12 h)/16 °C (12 h), the highest germination rate of sheepgrass seeds can be obtained, and it was identified that the 8-12 h in germi- nation is the key period where the expression of germination-related genes, such as EXPA2 was found to be highly upregulated.