Does Position in Cantaloupe (Cucumis melo L.) Fruit Affect Seed Quality?

Abstract

Effects of the location of seed development inside cantaloupe (Cucumis melo L.) fruit on seed germination percentage and vigor was compared for two Western Shipper cantaloupe cultivars (‘Ropey King’ and ‘Expedition’). Mean time to germination (MTG), as (NiTi )/ (Ni) where Ni is the number of newly germinated seeds at time Ti after imbibition was calculated as a measure of seed vigor. Fruit was grown in Woodland, CA, in a randomized complete block design, consisting of 4 blocks (i.e., replicates). Melons were harvested at the full slip stage of maturity and were measured and sliced into six equal sections (blossom end top, blossom end bottom, middle top, middle bottom, stem end top, and stem end bottom). Harvested seed was equally divided for germination testing without drying immediately after harvest (no seed storage, NSS), and after 6 months of seed storage (6MSS) of dried seeds. 6MSS was stored in a cold temperature-controlled (3.33°C, 35% relative humidity) refrigerator in sealed containers for six months, so moisture content did not fluctuate. Both cultivars showed improved germination percentage after 6MSS. Moreover, the 6MSS of both cultivars resulted in significantly higher (P ≤ 0.05) germination percentages in the stem end and middle sections of both cultivars. In contrast, MTG increased after 6MSS compared to NSS possibly because of differences in hydration. However, after 6MSS seeds from the stem end and middle fruit sections of both cultivars germinated faster (P ≤ 0.05) compared to seed from the blossom end indicating the most vigorous seeds developed in those sections.