Studies on the Crosses between Distantly Related Species of Lilies

IV. The Culture of Immature Hybrid Embryos 0.3-0.4mm Long

Abstract

1. Use of normal endosperm as nurse tissue.
Normal endosperm obtained from inter-clonal crossing was used as nurse tissue for the culture of immature hybrid embryos (0.3_??_0.4mm in length).
About 60 percent of the immature embryos could be cultured by putting them on normal endosperm.
The growth pattern of the embryos was ‘embryonic growth’ similar to the normal pattern seen in vivo, and was different from the ‘seedling growth’ usually seen on artificial mediums; it appears that the endosperm contains a kind of ‘embryo factor (s)’ which was absent in the artificial medium.
2. Culture on artificial medium containing amino acids.
Free amino acids contained in the normally developing endosperm were analyzed qualitatively and quantitatively and an artificial medium of the same amino acid composition was prepared.
The survival percentage of hybrid embryos was somewhat increased on prepared medium as compared with on basic medium, but it appears that the prepared medium used here was still lacking the so-called ‘embryo factor(s)’ since the growth pattern of the embryos was similar to ‘seedling growth’.