Mitsuo Kido’s research while affiliated with Niigata University and other places

Effect of amount and fertilized period of nitrogen, amount of phosphate, top dressing of potassium and amount of calcium silicate on fat content in rice kernel was observed. Results were summarized as follows: Nitrogen heavily fertilized, especially at ripening period, fat content in rice kernel decreased remarkably. Effect of amount of phosphate, potassium and calcium silicate on fat content was not recognized clearly. Above-mentioned effect of nitrogen was connected to percentage of total nitrogen in leaves at heading date, protein content in rice kernel and percentage of full ripened grain. In these studies, correlation coefficient and partial correlation between fat content (X1) and above factors were calculated and obtained results were as follows: In relation to percentage of total nitrogen content in leaves at heading date (X2) r12=-0.9066***, r12.4=-0.7355*, r12.3=-0.5670ns In relation to protein content in rice kernel (X3) r13=-0.8649**, r13.4=-0.7636*, r13.2=-0.1971ns In relation to percentage of full ripened grain (X4) (except No. 8 plot) r14=0.8634**, r14.3=0.7609*, r14.2=0.5862ns

This is an histochemical study of fat and aleurone grains in rice kernel during ripening Processes. The results obtained are summarized as follows: 1) It was observed that the aleurone layer and embryo was rich in fat by staining with Sudan black B and Sudan III. Epidermis of nucellus also showed black coloration with Sudan black B as its cell wall thickened. 2) Fat accumulation in aleurone layer began at the 7th day, and was completed at the 15th day after flowering respectively. 3) Aleurone gsains were clearly observed by ether treatment for removal of fat in cross section of rice kernel. 4) Aleurone grain of rice kernel was a globle, about 2μin diameter and simpld with no structure in it. 5) This aleurone grain was stained by fuchsin basic and carmine acetate, but not by safranine, methylen blue, methyle orange, eosin, neutral red and iodine potassium iodine 6) Protein reaction of aleurone grain by ninhydrin, Millon's reagent and mercuric chloride BPB was not observed. 7) This grain is soluble in 0.1 N-HC1, but insoluble in 0, 1 N-NaOH. In view of the fact that 0, 1N-HC1 is the reagent of extraction of phytine in cereal grain, aleusone grain of rice kernel seems to be rich in phytine. 8) It was late ripening period (the 20th day after flowering) that aleurone grain was clearly noticed in aleurone layer of rice kernel.

Quantitative distribution of protein, lipid, phosphate and potassium in rice kernel was investigated by comparison of contents in l, OOO kernels which were milled in different rate. A friction type test mill for l0g sample was used for milling. Conclusion was shown in Fig.5. Changes with milling time of protein and kernel weight in milled rice were almost similar. Content of protein in highly-milled rice was about 90% as compared with the content in brown rice. From these facts it is considered that starch tissue of kernel is rich in protein. Lipid was one of the most rapidly decreased component by milling, and content of lipid in highly-milled rice was about 23% as compared with the content in brown rice. This fact may Show that lipid in rice kernel exists almost in bran especially in aleuron layer. Content of phosphate and potassium also shows considerable rapid decreases but more slowly than the decreases of lipid. Reducing curve of these component resembles together. Content of phosphate and potassium was respectively 43% and 39% as compared with the contents in brown rice. Perhaps phosphate and potassium may be components of phitin which is contained in aleuron grain and in protein body.

In this studies we investigated influence of cultural conditions to amount of protein content in rice ripened kernel. The results are summarized as follows; 1) Conditions of many panicle formation per square meter, such as heavy nitrogen fertilization and dense planting, induced to low percentage of ripened grain, and grow small kernels. 2) Injury of root and leaf-blade, and lodging, also induced low percentage of ripened grain and small kernels. 3) Above different conditions grow as same as small kernels, and small kernels are usually protein rich kernels in this studies. The correlation coefficient between net solidity of rice kernel and amount of protein content of kernel was r=-0.903**. 4) According to our previous report, early variety usually formed protein rich kernels than late variety.

From these studies investigated on positions in panicle of ventral white, basal white, milky white like white core and milky white kernels, we considered on relations between shapes of white opaque parts and positions in panicle of these kernels. Based above consideration, we intend to make clear up the mechanisms of development of these kernels. Results are summarized as follows; 1) Milky white kernels developed at inferior positions in panicle as in Figure 1, and shapes are shown in Figure 2 to 13. White opaque parts of milky white kernels have many different shapes as shown in these figures. 2) Ventral white kernels developed at superior position in panicle as in Figure 1, and shapes are shown in Figure 14 and Figure 15. 3) Milky white like white core kernels developed in high prcentages in the second and the third grains of secondary branch of middle parts in panicle as in Figure 1, and shapes are shown in Figure 16 and Figure 17. 4) Basal white kernels developed in high percentages in the second grain of upper branches in panicle as in Figure 1, and shapes are shown in Figure 18 and Figure 19. 5) We make diagram of developmental process of superior medium and inferior spikelet as Figure 20. This figure is made by the consideration that inferior spikelets develop very slowly and need long days for full ripening. As shown in Figure 20, the most rapidly development time of superior spikelet corresponds to the early development time of medium spikelet (about several days after flowering). As same as above mentioned, the most rapidly development time of medium spikelet corresponds to the middle development time of inferior spikelet (about twenty days after flowering).

In this studies we observed on opaque kernel, especially green opaque kernels. The results are summarized as follows: 1) Opaque kernels are classiffied in several types according to its shapesas green opaque kernel (type 6, type 7-1, type 7-2, ), white opaque kernel, small translucent green kernel, and monstrous kernel. Tissue and outlook of green opaque kernel are shown in Figure 1 to Figure 12. Type 6 and type 7 showing green opaque kernel, have immature parts (starch-less tissue) in endosperm as in Figure 4, 6, 8, 10, 12. 2) Developmental process of kernels are classified into 6 types showing in Table 1. According to Table 1, early growth of opaque kernels are suppressed by the competition of superior kernels. And in the late ripening stage at 17 days after flowering, opaque kernels grow comparatively rapid. 3) From the incressing curve of 1000 kernels weight of inferior spikelet, we observed the competition of growth of kernel among inferior spikelet and superior spikelet as in Figure 9. 4) Protein content of opaque kernels are always richer than ripened kernels. 5) If we could promote growth of opaque kernel in late stage of ripening, some of these might be grown to ripennd kernel in harvesting time, then we consider that above results show its possibility.