Abstrakt: |
Kernel vigor of 16 combinations of four recessive endosperm‐altering genes — amylose‐extender(ae), dull(du), sugary(su), and waxy(wx) — was measured to evaluate the potential of these genotypes for sweet‐corn (Zea maysL.) use. Each genotype was studied in near‐isogenic lines, ranging from five to seven backcrosses, of sweetcorn inbreds ‘S3‐61’, Ia5125’, and ‘Ia453’. Replicated 50‐kernel samples were placed in germination toweling, and measurements of (a) germination percentage, (b) average shoot length, and (c) dry weight of roots and shoots were made after growing in cold‐stress test (7 days at 10 ± 0.5 C followed by 5 days at 25 ± 0.5 C). Genotypes with the aephenotype (ae, ae du, ae su, ae wx, ae du wx, ae su wx) had poor vigor and exhibited some reduced germination and decreased seedling shoot length. In contrast, genotypes with the suphenotype (su, su wx, du su,and du su wx) performed consistently better than genotypes homozygous for ae. Measurement of vigor based on total growth weight (c) gave more consistent results across inbreds than did measurements (a) and (b) averaged over the 50‐kernei sample size. Differences among inbreds were large, indicating that the choice of inbred parents may overcome the deleterious effect of some endosperm gene combinations and permit their use as new sweet corn types. |