A simple analytical procedure for the analysis of the chlorophyll protein complex was developed using two step (Trlton X-100 → SDS) electrophoresis instead of chlorophyll isolation by sucrose or Percoll density gradient centrifugation. Triton X-100 (polyoxyethyleneglycol p-t-octylphenyl ether) at a 40% concentration dissolved effectively water insoluble proteins from the thylakoid membrane including the chlorophyll protein cornplex. The chlorophyll protein complex appeared as closely overlapping green bands and the bond between protein and chlorophyll was not destroyed after separation by polyacrylamide gel electrophoresis (PAGE) using 3% Triton X-100 in a 7% Davis buffer system. Stripes in the polypeptide pattern of these bands were cut horizontally from the gel, treated with SDS (sodium dodecyl sulfate) and then again subjected to SDS-PAGE. The polypeptide patterns of the chlorophyll protein complex of petunia, chrysanthemum, 60 varieties of rice (Oryza sativa L.) and 11 Oryza species were compared. In the genus Oryza, all the varieties and species showed a similar pattern except for some Oryza species i.e. O, alta (CD genome), O. latifolia (CD), and O. brachyantha (F). Moreover, there was no difference in the polypeptide patterns obtained with this method when compared to the conventional method.

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Elimination of chromosomes, which is detected by the presence of laggards at telophase, occurs frequently in the spike primordia, but not in the root meristems of the hybrids between H. vulgare cv. Amsel and H. bulbosum L. Cordycepin (10^-5M), cycloheximide (10^-5M) and colchicine (0.1%) were applied for 30 min to the root meristems of H, vulgare L. cv. Amsel and H. bulbosum L. (4x), and their triploid hybrid E159. Colchicine did not induce laggards at telophase in Amsel, H. bulbosum and hybrid E159, although C-metaphases were observed. Spindle disruption may not be involved in the chromosorne elimination of the hybrids. Cordycepin and cycloheximide induced frequently laggards at telophase in the hybrids at 60 min after the end of the treatments, while no laggards were observed in Amsel and H. bulbosum. Hybrid E159 appears to have the partial suppression of RNA or protein syntheses related to the centromere function, and is sensitive to cordycepin and cycloheximide. Cordycepin and cycloheximide may enhance the suppression of the centromere activity and results in the laggards at telophase. RNA and protein synthesis during G₂ or prophase is involved in the chromosome elimlnation in H. vulgre-H. bulbosum hybrids. Cd-staining method, which was reported to distinguish active centromeres from inactive ones of human chromosomes, were modified for chromosomes of Hordeum species. The modified Cd-staining revealed clear centromere dots only in the centromeres. However, both normally separating chromosomes and laggards showed centromere dots. The modified Cd-staining may not stain the centromere structures related to the centromere-microtubule interaction.

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In order to examine the selection efficiency of rice grain size, the narrow-sense heritability was estimated for grain length and grain width from parent-offspring correlation and selection response in segregating populations from various cross combinations. Five cultivars, BG 1, Arborio J1, Taihou, Nakateshinsenbon and Koshihikari, were used as parents. The heritability estimate averaged over ten F₂ populations was 0.800 for grain length, and 0.555 for grain width when estimated from parent-offspring correlation, Among the ten populations, there existed a positive correlation between heritability estimate and the magnitude of genetic variance for both grain length and grain width. The average heritability estimate for grain length obtained from selection response was 0.679. The narrow-sense heritability estimates for grain length and grain width were high in general as compared with heritability for other agronomic traits in rice. The estimates for grain length and grain width did not fluctuate drastically with generation advancement from F₂ to F₄. The present results suggest that selection for grain size of rice is effective even in early segregating generations after crossing.

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Plant regeneration in tissue cultures of Ipomoea triloba L., one of the related species of sweet potato, I. batatas (L.) LAM., was studied. Stem, petiole and leaf explants of I. triloba L. produced white friable calli on MURASHIGE and SKOOG (MS) medium supplemented with 0.5mg/l 2, 4-dichlorophenoxyacetic acid (2, 4-D), 1.0mg/l kinetin, 3.0% sucrose and 0.8% agar, pH5.8. The induction frequency of callus reached 100.0% on all media used. When transferred onto MS medium supplemented with 0-0.4mg/l 3-indoleacetic acid (IAA), 0-10.0mg/l 6-benzylaminopurine (BAP), 3.0% sucrose and 0.8% agar, pH5.8, 65.0-100.0% of the calli formed adventitious roots. Except 0 level of IAA and BAP, the concentrations of IAA and BAP did not significantly influence the forination of adventitious roots. All calli cultured on the adventitious root formation medium were transferred onto hormone-free MS medium containing 3.0% sucrose and 0.8% agar, pH5.8, and the shoots were directly regenerated from (the green areas formed on) the stem-, petiole- and leaf-derived calli at the high frequencies. The highest frequencies of stem-, petiole- and leaf-derived calli regener-ating shoots were 68.4%, 42.1%, and 55.0%, respectively. The concentrations of IAA and BAP added to the adventitious root formation medium significantly influenced the shoot regeneration. The optimal concentrations were 0.4mg/l IAA + 2.0mg/l BAP to stem-derived calli, 0.4mg/l IAA + 5.0mg/l BAP to petiole-derived calli and 0mg/l IAA + 1.0mg/l BAP to leaf-derived calli, respectively. Some adventitious roots also produced a small number of shoots on the hormone-free MS medium. The regenerated shoots developed into whole plantlets after they were transferred onto the fresh hormone-free MS medium. No morphological variations were observed in the regenerated plants.

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Rice cultivar Sateng was analyzed for resistance to bacterial blight of rice (BB) caused by Xaeathomonas campestris pv. oryzae, using Japanese and Philippine BB races. Sateng had been reported to have a recessive gene, xa-9. However, it showed reactions similar to those of Chugoku 45, Java 14, and Zenith against Japanese and Philippine races in our preliminary experiment. Therefore, Sateng was subjected to an allele test with the above cultivars which have Xa-3 gene, using Japanese and Philippine races. The reaction of the F₂ population from the cross Toyonishiki/Sateng to Japanese race IIIA showed that Sateng has one domlnant gene. All F₂ plants of Chugoku 45/Sateng and Sateng/Zenith were resistant with browning around the lesions. The reaction of F₁ and F₂ populations from the cross of IR24/Sateng and Toyonishiki/Sateng also showed that Sateng has one dominant gene for resistance to Philippine races 1 to 4. Lesion length of the F₂ plants was somewhat variable due to segregation of minor genes. These results indicated that Sateng has a dominant gene which is allelic to Xa-3. Analyis of the F₃ progenies from the cross Java 14/Sateng using Philippine races confirmed these results.

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A simple and efficient method for identification of hybrids after cell fusion was established by combining a method for the efficient extraction of DNA from very small amounts of plant tissue and Southern blotting with non-radioactively labeled rDNA from rice as a probe. One hundred milligrams of leaf or callus tissue, are sufficient for identification of the hybrid, and the amount of material can be reduced to as little as 10 mg. Since this method permits selection of parasexual hybrids not only at the plantlet stage but also at the callus stage, hybrids can be identified at the early stages of the development of the products of cell fusion.

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Many studies on soybean have been carried out to raise the productivity, oil and protein content and to breed the cultivars resistant to many diseases (SAITO et al., 1980; OJIMA et al., 1987). However, few studies have been conducted on green-soybean in which the eating quality, i.e. flavour, sugar content and hardness may be the important characters (KOUDA, 1934). In the current experirnent, the water absorption characteristics of ripened seeds were examined using 35 green soybean cultivars and 86 ordinary soybean cultivars. As the water absorption characteristics, the followings were measured, i.e. the rate of water absorption per dry weight of seed coat and cotyledon, the rate of water absorption per seed volume, the rate of embraced water in seeds and regression coefficients of water absorption to time during a period in which the water absorption progresses linearly. The discriminant analysis for these five water absorption characteristics showed that the green soybean seeds had high values of the rate of water absorption per cotyledon dry weight, and the ordinary soybean seeds had high values of regression coefficients (Fig. 2). These results indicate that even the ripened seed of green soybean retain the characteristics relating with the eating quality, i.e. to absorb a large amount of water due to a high content of "internal forces" (SHULL, 1914) which is attributed to content of sugars and aminoacids and due to the soft texture of soybean seeds (KAWAKAMI, 1949; OKAMURA, 1968). The high water absorption of green soybean seeds may also be ascribed to their soft tissue architecture of cotyledon.

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Heritability values of wet endurance in F₄ - F₆ populations were estimated to improve wet endurance of malting barley. Materials were grown under excess soil moisture treatment (irrigated condition) at the internode elongation stage. Selected characters concerning wet endurance were the degree of dead leaf expressed by the score 0 (most tolerant) -5 (most susceptible) and the tolerance index (the mean value of excess soil moisture plot/that of control plot) of grain yield and culm length. Heritability of wet endurance in F₄ - F₆ populations was estimated by (M'₁ ^^^--M'₂^^^-) /(M₁^^^- - M₂^^^-), where M₁^^^ and M'₁ ^^^- were mean value of selected lines for higher tolerance to excess soil moisture and their progenies, respectively, and M₂^^^-and M'₂^^^- were those for lower tolerance to excess soil moisture and their progenies, respectively.

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Shoot apices of Oenothera erythrosepala were cultured on MS medium supplemented with various concentrations and combinations of naphthaleneaceticacid (NAA) and 6-benzylaminopurine (BA). Effect of hormonal concentration on number of newly induced shoots per shoot apex placed was evident. The media containing 0.2mg/l NAA 0.2mg/l BA and/or 0.2mg/l NAA 2.0mg/l BA were suitable for shoot multiplication and 2.0mg/l NAA for rooting. There was a little difference in root formation and root hair development according to the gelling agents used, but the survival rate was not affected by them.

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A total of 36 soybean genotypes, 21 of which had provided no somatic embryogenesis on a medium containing 30g/l sucrose in a previous study, but the other 15 genotypes had produced higher numbers of somatic embryos, were further examinated for their response to a revised medium containing 5g/l sucrose. Somatic embryogenesis occureed in all the tested genotypes, however the efficiency for each genotype differed significantly.

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