Morphological investigations on the development of embryo in cereals. : II. Barley - (1) General process of the embryo formation. (Preliminary).

[摘要] A study has been made of the anatomical development of the embryo in wheat, barley, rye and oats from a point of view of the developmental morphology of crops. In this study, the writer has inquired, the developmental process having been detailed especially the progress of differentiation of the various parts and the change in the size and shape of the embryo at different stages from the time of anthesis or hand-pollination to the maturation of the ovule into a seed. The material used in this study consisted of 19 varieties belong to Hordeum ssativum JESS., with different growth-habits and characteristics of the plant and grains. Although, the general process of the development having been summarized only about one variety in this paper. The one variety was pollinated by hand-pollination, and the others were examined with the natural pollinated flowers. The method of preparing the material for microscopical study was as follows: Freshly harvested samples were fixed in BOUIN's or SCHAFFNER's fluid, and embedded in paraffin by the usual methods. Paraffin sections were cut at 8μ to 15μ, depending on age, and stained with double stain for erythrosin and DELAFIELD'S haematoxylin. The result of this investigation about the one variety - Ehimehadaka-1 - is summarized as follows: (1) The first cell division of the proembryos was completed about 48 hours or more after hand-pollination. (2) The differentiation between the dermatogen and the central core occurs at the stage of 4 or 5 days old after pollination. (3) The first sign of differentiation of the rudiments of each organ in the proembryos occurs 9 or 10 days after pollination. (4) About 11 days old after pollination the development of the coleoptile is seen, and the rudiment of the first foliage leaf may be seen somewhat later. (5) The rudiment of the second foliage leaf appears at the stage of 15 days old, and the third foliage leaf may be seen at the stage of 20 days old after pollination. (6) The fourth foliage leaf is the upper most leaf on the plumule of embryo in barley, and the stage of the differentiation of the leaf is from 35 days old onwards. (7) The epithelial layer of the scutellum forms its original shape about 20 days old. (8) About 20 days old after pollination all orgns of the embryo are completely differentiated, but they grow perfectly about 30 days old after pollination.

[学科分类] 农业科学（综合）