Jun Inouye

Effect of low water potential of the culture medium on mesocotyl elongation of rice seedlings

At a soil water content of water potential of ca. -3.1 to -6.2 bars, mesocotyl elongation of both indica and japonica type rice was extremely stimulated. It was also stimulated in an aseptic culture medium (2.5-4.0% mannitol, water potential ca. -3.5 to -5.5 bars). The stimulation of the mesocotyl may be caused by cell multiplication.

Studies on the Seedling Emergence in Crops : Effect of compaction of covering-soil on the emergence in some cereals

This investigation was conducted to make clear the effects of compaction of covering soil on the strength of plumule-elongation and the seedling emergence in some cereals. The materials used were as shown in table 1. (1) In all the cereals used in this experiment, the strength of plumule-elongation under compacted covering-soil was stronger than that under non-compacted, irrespective of cultural temperature and plumule length (Table 2). (2) In each cereals, the area of cross section of plumule was larger in the plumule grown under compacted covering-soil than in the plumule grown under non-compacted, respectively (Table 3). Furthermore, bending strength of the former was stronger than that of the latter (Table 4). (3) Under compacted soil conditions, crops with long mesocotyl were highest in seedling emergence followed by crops with long coleoptile, and crops with short mesocotyl or short coleoptile (Figure 2).