Kernel Maturity, Seed Size, and Seed Hydration Effects on the Seed Quality of a Sweet Corn Inbred

Abstract

Abstract To understand early development of seed quality, seed lots of sweet corn (Zea mays L.) inbred PGG-27B were harvested from an increase field at 10 stages of maturity, beginning when kernel moisture was at 59% and continuing to 19% kernel moisture content (42 to 103 days after pollination, respectively). Seed lots were dried, hand-shelled, sized, and tested for standard germination and subjected to the seedling growth cold test (SGCT). Endosperm, embryo, and kernel dry weights, and endosperm : embryo (END:EMB) ratios were monitored as the seed matured. Field tests were planted to determine the influence of kernel maturity, grade, and hydration on stand establishment and early seedling growth. Seeds were partially hydrated by mixing with moist vermiculite and screening from the substrate when seeds had reached 30% moisture content. Results from hydrated seeds were compared to those from seeds at ≈10% seed moisture to determine the effect of presowing seed hydration on seedling establishment. The seed hydration effect depended on the environment, but seed size was shown consistently to influence emergence and early seedling dry weight. Seed harvested at 45% to 54% moisture had better stand establishment than seed harvested at the more typical moisture of near 35%. The stage of maturity, determined by kernel moisture, at which PGG-27B was harvested had little effect on standard germination. Hydrating the seed prior to the SGCT improved seedling growth for all early kernel maturities and all seed grades. Embryo dry weight of composite samples increased steadily up to the fifth harvest period (38% seed moisture), then leveled off. Kernel and endosperm dry weights were more variable at the fifth harvest than at others, but followed the same general pattern. The ratio of END:EMB dry weight decreased from the first to the fifth harvest, where it continued at a value near 4.9 through harvest 10. Seed moisture at harvest, seed size, and presowing seed hydration were shown to influence the seed quality of PGG-27B.