Heterosis and Hemeostasis in Secale montanum Guss. ✕ S. cereale L. Hybrids II. Reproductive Characteristics1

Abstract

F1 hybrids between Secale montanum (P.1.253956) the female parent and three varieties (‘Florida Black,’ ‘Gator,’ and ‘Wrens Abruzzi’) of S. cereale were made. F2 populations were produced by interpollination within each F1 population.Under natural daylength and space‐planted conditions, 40% of the S. montanum plants produced seed in 1965‐66 and 10% in 1966‐67, whereas 100% of the plants in the S. cereale varieties and 70 to 100% of the F1 and F2 plants produced seed. For number of seeds, seed weight, and grain yield, the F1 populations were generally intermediate to the parents with S. montanum the lower parent in all combinations. The F2 populations tended to produce a larger number of seeds than the corresponding F1. Substantial differences resulting from the S. cereale variety involved and year tested were observed. The variability of both the F1 and F2 populations as a result of differences in years and the variation within the F1 populations were greater than the higher parent. However, the S. cereale variety involved was a major factor.With 16‐hr daylength, the F1 populations were generally below or equal to the mid‐parent in percent stainable pollen with S. montanum the lower parent in all combinations. However, the corresponding F2 populations were higher in percent stainable pollen with two out of three combinations exceeding the S. cereale parent. The pollen diameter of the F1 and F2 populations was generally intermediate to the parents with S. montanum the lower parent in all combinations.