Fruit Maturity and Intra-Spadix Position Affected Seed Quality of Amorphophallus muelleri Blume

The seed harvesting process for Amorphophallus muelleri Blume is complicated by asynchronous flowering and fruiting. These factors affect the quality of the fruit and seeds, including fruit color, seed viability, and vigor. Pericarp color, as a simple indicator of fruit maturity, can be used to determine the best harvest time. At the M30% fruit maturation stage (30%–49% red pericarp), pericarp colors were more diverse across positions, including dark red, orange, yellow, and greenish yellow. The M50% (50%–74% red pericarp) included red, orange, yellow, and greenish yellow. The pericarp colors at M75% (>75% red pericarp) were more uniform, consisting of red, orange, and yellow. There were no significant differences in seed moisture content among spadix maturity stages, 62.49% (M30%), 63.42% (M50%), and 61.07% (M75%). Maturity stage and position affected the physical and physiological quality of the fruit and seeds. The well-filled and rotten fruits in the spadix increased as fruit maturity advanced. The highest number of empty fruits was found at M30%, while the highest seed dry weight was found at M50%. The proximal position had a higher percentage of empty fruits and a greater dry weight than the distal and middle positions. M75% had the highest average rate of well filled fruit (90.83%) and the lowest average dry weight (8.1 mg per seed). The M50% maturity stage had the highest average dry weight (9.3 mg per seed) and the highest average viability of 93.1%, indicating that the seeds had reached physiological maturity.