Physiological and Biochemical Changes in Hybrid Maize Seed Quality during Ambient Storage in Different Packaging Materials

The present study investigated the impact of seed moisture content and packaging materials on the quality of maize hybrid PMH 1 seeds under ambient storage conditions. Maize seeds harvested four months prior were desiccated to various moisture levels (12%, 10%, and 8%) and stored in different packaging materials, including laminated polypropylene bags, non-laminated polypropylene bags, and high-density polyethylene (HDPE) bags. Seeds with 12% moisture content stored in cloth bags served as the control. The study found that seeds stored in laminated polypropylene bags, non-laminated polypropylene bags, HDPE bags, and cloth bags maintained germination rates above 90% for up to 13 months, meeting the Indian Minimum Seed Certification Standards (IMSCS). However, germination rates gradually declined with extended storage, and no storage treatment could maintain germination above IMSCS after 13 months. Seed moisture content exhibited fluctuations corresponding to the relative humidity of the environment, with greater variation observed in seeds stored in cloth and polypropylene bags compared to those in HDPE bags. There was a consistent decline in α-amylase activity and antioxidant enzyme levels with prolonged storage, regardless of the packaging treatment. Food reserves, including sucrose, starch, oil, and total soluble proteins, decreased over time, while total free amino acids increased. Protein profiling revealed that the intensity of electrophoretic bands corresponding to polypeptides of molecular weights 44 and 52 kDa was higher in fresh seeds compared to seeds stored for 15 months under various packaging treatments. Despite statistical parity in germination rates across different packaging materials, polypropylene bags (both laminated and non-laminated) emerged as cost-effective and durable alternatives to cloth and HDPE bags, owing to their lower cost and higher flexural strength.