Relationship between Environment during Seed Development and Seed Vigor of Two Endosperm Mutants of Corn

Abstract

Seeds of 2 corn (Zea mays L.) endosperm mutants, shrunken-2 (sh2) and sugary (su), were produced in the field and greenhouse and harvested 18 to 46 days postpollination (dpp). Seeds of su accumulated dry weight rapidly after 26 dpp, while sh2 seeds had nearly attained their final weight by this stage. This resulted in a larger endosperm in su. Greenhouse-grown sh2 seeds weighed more than field-grown sh2 throughout development. Germination and seedling growth of greenhouse-grown sh2 seeds under optimum conditions were greater than that of field-grown sh2 when seeds were older than 26 days. Greenhouse-grown sh2 seeds 26 days and older germinated as well as field- and greenhouse-grown su with comparable seedling growth. Germination of field-grown sh2 seeds was much higher throughout development in the cold rolled-towel test compared to the cold soil test. Viability and vigor differences between immature seeds of both genotypes were not distinguishable by the cold, rolled-towel test, but were very noticeable in the cold soil test. Under cold soil test conditions, greenhouse-grown sh2 seeds had significantly greater emergence than did field-grown sh2 38 dpp and older. Mature greenhouse-grown sh2 and su seeds were of equal viability and vigor in the cold soil test.

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

“…Selection to increase seed weight and/or the END:EMB dry weight ratio was suggested as a means for improving seed vigor in high-sugar sweet corn cultivars, but the END:EMB ratio of 4.9 found for inbred PGG-27B compares favorably with the ratios reported for other sugary (sw) cultivars such as 'Iochief', 'Iobelle', and 'Golden Cross Bantam' (24). The END:EMB ratio of the inbred used in this study was considered adequate for vigorous seedling growth under all conditions; thus, endosperm weight may not be related to sweet corn vigor, as previously believed (22).…”

“…Environmental conditions that may decrease seed quality include hot, dry weather during pollination and fertilization (7), or exposure of kernels to freezing temperatures (18). In a greenhouse environment, the exclusion of pests was one factor that aided in the production of high-quality sweet corn seed (22). Seed moisture at harvest was reported to influence germination percentage and vigor (14).…”

“…Most studies that have examined kernel maturity used field corn inbreds or hybrids as experimental material. Sweet corn kernel maturation has received some attention (8,9,21,22,24), but the literature concerning the need for acceptable eating quality (e.g., tenderness) and good seed quality is limited. Eating quality and seed quality requirements are often in conflict (8).…”

Germination Under Cold Soil Conditions

“…Low-vigor seeds seem to be particularly injured by imbibition at low temperatures (64,73,74). Finally, the environment during seed development can have a large effect on seed vigor and the capacity to germinate at low temperatures (6,63,64).…”

“…Low-vigor seeds seem to be particularly injured by imbibition at low temperatures (64,73,74). Finally, the environment during seed development can have a large effect on seed vigor and the capacity to germinate at low temperatures (6,63,64). Late-maturing soybean cultivars germinate better at low temperatures than early maturing types (6), perhaps due to development during lower temperatures (which could affect seed coat characteristics), to the composition of membranes being formed during seed development, or to some other unexplained factor.…”