Preliminary Study on Germination Capacity and Desiccation-tolerance of Cassia hirsuta Seeds at Various Developmental Stages

The germination capacity of Cassia hirsuta seeds rose gradually at the early developmental stages, ie, since 39 d after anthesis, germination percentage (GP) and germination index (GI) reached the maximum at 53 days after anthesis (DAA), vigor index (VI) reached the maximum at 67 DAA, but then all decreased. The seed moisture content (MC) decreased gradually at different rates. Seed dry weight approached the maximum value at 67 DAA and a significant dehydrating stage appeared at 67～74 d. The desiccation tolerance of seeds gradually increased from 46 to 60 DAAand reached the maximum at 60 DAAfollowing by a decrease gently dehydrating could significantly improve GIand VIof seeds at 46 and 67 DAA. The seeds with lowest MC at 60～67 DAA could tolerate approximately 10% MC, so the seed appeared to be orthodox seeds.