Effects of seed mass variation on desiccation sensitivity of <i>Syzygium jambos</i> (Myrtaceae) seeds

Syzygium jambos seeds greatly vary in seed size (mass) in the same seed population. To accurately reflect the desiccation sensitivity of S . jambos seeds, freshly harvested seeds were divided into five grades based on seed mass, and then subjected to drying, followed by germination tests. Non-graded (mixed) seeds were also subjected to drying and germination experiments. Both the mixed and graded seeds lots with high initial moisture contents germinated to 100% at 30/20°C in light. During whole-seed desiccation, the smaller the seeds, the faster they lost water and viability. The median moisture content for 50% of viability loss of mixed seeds with heterogeneity in mass was around 40%. Taken together, rose apple seeds are desiccation-sensitive. Large (heavy) seeds lost water more slowly; smaller (light) reached a lethal water content earlier, resulting in earlier death.