The effect of p-fluorophenylalanine (PFP) on the induction of variations in the chromosome number was investigated in cultured shoot tips of Vitis clones, including triploid and tetraploid cultivars and interspecific hybrids. A higher concentration (400 μM) of PFP inhibited the growth of the shoot tips. The abnormal mitoses and the variations in the chromosome number including the induction of haploid and aneuploid cells were observed in the shoot tip cells treated with PFP. Variations in the chromosome number were also observed in the root tip cells of regenerated plants after PFP treatment. However, most of cells with abnormal chromosome number co-existed with normal cells. The average perc6ntage of the anormal cells was about 1.0% among total observed cells of all the clones examined. In most of the cases the abnormal chromosome number observed in the roots was euploids, regardless of the ploidy level of the clones examined. There were fewer aneuploids in root cells than in the shoot tip cells. In all the experiments, two variants (about 0.3% of the plants checked) had large sectors with reduced numbers of chromosomes in the shoots. One was a triploid-tetraploid variant from the tetraploid cultivar Kyoho, and the other was a diploid-triploid variant from the triploid clone KC-1.

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Some of the factors which influence the in vitro shoot-forming capacity of cotyledon explants of red pepper (Capsicum annuum L. cv. Yatsufusa) were studied. Benzyladenine (BA) was found to be more effective than kinetin (K) in inducing shoot formation in cotyledon explants cultured on MURASHIGE and SKOOG (MS) medium. Among the BA levels tested, BA at a concentration of 3 to 7 mg/l induced the largest number of shoots per explant. Auxin (indoleacetic acid and naphthaleneacetic acid) in combination with cytokinin (BA) inhibited shoot formation but promoted callus and root formation. Cotyledon explants excised from the 12-day-old seedlings gave the largest number of shoots per explant and the frequency of shoot formation was significantly decreased as the age of the seedlings increased. Intact cotyledon with petiole and trimmed cotyledon with petiole showed a significantly higher frequency of shoot formation than blade and petiole of cotyledon. Among four kinds of growing media on which seeds were sown and seedlings were grown, full-strength MS solution and half-strength MS solution were found to be more effective than tap water for the induction of shoot formation on cotyledon explants. The highest percentage of shoot-forming explants and the largest number of shoots per explant under the defined optimum conditions were different in each trial, ranging from 90 to 100 per cent and 8.6 to 11.9, respectively. Shoots were rooted when transferred to the same medium supplemented with indoleacetic acid or naphthaleneacetic acid at the concentration of 0.5 mg/l and complete plantlets could be regenerated within 7 weeks after the beginning of culture.

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The aftereffects of the temperature to which parental rice plants were exposed during seed development on the early growth of seedlings, i.e. the growth of seedlings after seed germination in dark, in the next generation were investigated. The length of the shoots, mesocotyls, coleoptiles and 1 st leaves of the seedlings from the seeds produced at a day/night temperature of 30/25°C (H seedlings) was longer than that of the seedlings from the seeds produced at a day/night temperature of 17/12°C (L seedlings). The aftereffects of the temperature during seed development on the growth of seedlings was most clearly recognized in the indica cultivar. Surjamukhi, among the cultivars used. In particular, the mesocotyl length of the H seedlings of Surjamukhi was considerably long as compared with the other cultivars. The growth pattern of the G seedlings from the seeds produced in a glasshouse was similar to that of H seedlings for shoots and that of L seedlings for mesocotyls. The similarity of the growth patterns of the coleoptile and I st leaf of H or L seedlings to those of G seedlings varied with the cultivars used. On the other hand, the growth of roots was little affected by the temperature during seed development. The adventitious root length of the H seedlings of Surjamukhi was particularly shorter than that of the L seedlings. Our results indicate the temperature during seed development affects the growth pattern of seedlings and the aftereffects of the temperature varies with rice cultivars.

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The variations of the heading response to daylength in foxtail millet (Setaria italica P. BEAUV.) were investigated. Twenty strains of foxtail millet collected from various parts of Eurasia including islands of Southeast Asia were cultivated under three daylength conditions : Short-days (10 hrs. light +14 hrs, darkness), natural daylength (14.5 hrs-11.5 hrs. light+9.5hrs. -12.5hrs. darkness) and long-day (16 hrs. light+8hrs. darkness). Based on the variations of the response, three types were identified. Type I : early maturing strains indifferent to daylength condition ; Type II : very long basic vegetative growth period ; Type III : short basic vegetative growth period and high sensitivity to daylength: Type I is represented by strains from areas of a higher latitude such as Europe, Central Asia and northern part of East Asia. Type II is represented by strains from low latitudinal areas such as Halmahera Is., Indonesia and Luzon Is., Philippines. Type III is found in late maturing varieties growing in areas of a latitude of around 30 ??, such as "Shimokatsugi", a landrace of mountainous villages on Shikoku Island, Japan. The other strains were scored as intermediate between these types. These findings suggest that there is a relationship between the types of heading response to daylength and the geographical distribution which determines the planting season in traditional cultivation practices of foxtail millet.

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Effects of the cytoplasms of Aegilops squarrosa. Ae.kotschyi, Ae.speltoides and Ae.longissima on the effectiveness of selection and association of agronomic characters were investigated using a total of 200 F₄ and F₅ lines which were derived through selection in early generations of the cross combinations between allo- and euplasmic Norin 26 and euplasmic Norin 61. The selection was carried out on heading date, ear length, ear weight, ear number and yield per plant. The selection was effective for heading date and ear length and weight in all of the cytoplasms tested, No remarkable difference was recognized among the cytoplasms regarding the frequency of deviant lines for each selection character. It was observed, however, coincidently with the previously reported results of F₂ and F₃ populations, that the cytoplasm of Ae. kotschyi produced the widest range of combination of characters. Some promising early lines which were rather positively modified for the size of ear, were obtained in the cross combination carrying this cytoplasm. These lines may be used effectively as a genetic stock for wheat breeding in Japan. Effects of the other Aegilops cytoplasms were neither prominent nor con-sistent with the results observed in the F₂ and F₃.

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KTILPs (Kunitz trypsin inhibitor like proteins) of wild soybeans (Glycine subgenus Glycine) are the antigenic relatives with KTI's found in cultivated soybeans (G. max). Seeds of wild soybeans contain two different KTILPS (S and F proteins) which migrate slow and fast on polyacrylamide gel electrophoresis (PAGE), respectively. The S proteins are single protein like KTI but the F proteins are composed of two different peptides (f1 and f2). They exhibit considerable variances of mobility (Rf value) on PAGE (Table 1), the ratios of S to F protein (Fig.1, Table 1) and the molecular sizes of S protein, f1 and f2 peptides on SDS-PAGE (Fig.3, 4). These three characteristics of KTILPs were compared in 22 lines of the five Glycine species (G.latifolia, G.tabacina, G.clandestina, G.canescens and G.tomentella) listed in Table 1. Seven migration patterns were distinguished by two dimensional gel electrophoresis consisting of PAGE and SDS-PAGE (Fig.3, 4). As G.latifolia and G. tabacina were separated into two (LAT A, B) and three (TAB A, B, C) subspecific groups, whereas G.clandestina formed a homogenous entity.

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Rice Norin-PL 5 (PL 5) was developed as a Japonica type parental line resistant to dwarf, a rice virus disease. The inheritance of resistance of PL 5 to dwarf and to the green rice leafhopper (GLH), Nephotettix cincticeps, which is the vector of rice dwarf virus, and the relationship between dwarf resistance and GLH resistance were investigated in the present study. GLH resistance was analyzed using F₁ and F₂ populations of the crosses between PL 5 and. susceptible varieties by two methods i. e. the flag leaf test and the seedling test. In the flag leaf test, the number of survivals in the 10 young instar nymphs caged with one piece of flag leaf in a test tube was counted after four days. Segregation of the F₂ populations fitted the ratio of 9 resistant : 7 susceptible (Table 1). The F₁ individuals were as resistant as PL 5. These data indicate that the GLH resistance of PL 5 is controlled by two dominant complementary genes. In the seedling test, one seedling at the second leaf stage was caged with five young instar nymphs in a test tube and the number of survivals was examined after three days. The same result as in the flag leaf test was obtained from the F₂ population of the cross PL 5/Saikai 160 (Table 2).

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The yield of rice per unit area in Japan has continuosly increased resulting in overproduction of rice. This situation led the researchers to differentiate their efforts in developing new use of this hop, besides the improvements of agronomical and food qualities. To be used as fodder or as industrial resouces, new characteristics must be sought. To improve the lipid content a new rice variety was developed. The relationship between the thickness of aleurone, oil content and composition of fatty acids were analyzed in the giant embryo mutant, compared with the original cultivar, Kinmaze. The 1000 grain weight of the giant embryo mutant was slightly lower than that of kinmaze. The embryo weight of the mutant was 2.6 times higher than that of Kinmaze but no difference was observed in the aleurone weight. The oil content per grain of the giant embryo mutant was 36% higher than that of Kinmaze. The increase of stearic acid in the embryo resulted in a content of stearic acid in the mutant almost twice as high as that of Kinmaze. The oil content of the giant embryo mutant increased to 3.9% from that of the normal oil content (2.6%) of Kinmaze. However, the fatty acid composition of the giant embryo mutant except for stearic acid was normal. Therefore the increase of oil content in the giant embryo mutant is a favorable character, though the amount is still low. Efforts are being made to increase the thickness of the aleurone layer and the oil content of the endosperm.

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Eleven male-sterile mutants were induced from a rice variety Sasanishiki by ethyleneimine and γ-ray treatments of seeds. Nine of them produced no pollen grains or only abortive ones and the other two showed extremely low pollen fertilities. The eleven mutants were crossed with the original variety. All F₁ hybrids were fertile, i.e., normal in both pollen and seed fertilities. In eight of their F₂ progenies, fertile and male-sterile plants segregated in a ratio of 3 to 1, indicating that the male sterility of the eight mutants was controlled by a single recessive gene. In one of the other three, segregation ratio suggested the participation of two recessive genes, while in the remaining two, the number of the genes responsible for male sterility could not be determined.

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Protoplasts of L.pimpinellifolium were isolated from cotyledons from about 10 day old seedlings which were grown under sterile conditions at 20°C and 4, 500 lux. Isolated protoplasts were cultured in a plating medium of TM-2 (SHAHIN, 1985) with liquid on agarose and, subsequently, on the second medium based on TM-3 (SHAHIN, 1985) under the conditions of 25°C and 400 lux. The calli brought up to about 1.0 mm calli were transferred onto the shoot induction medium of TM-4 (SHAHIN, 1985) where shoots never appeared. Calli were again transferred to modified MS medium (MURASHIGE and SKOOG, 1962) supplemented with ZR (Zeatin riboside) on which shoots were regenerated at the rate of 27% during the ten day culture from 45 days after plating of proto plasts.

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Between common camellia and golden camellia, hybrid plant was produced by embryo culture. The most proper season for embryo culture was late July just prior to embryo degeneration. The leaf colour, shape, serration, venation and root colour of hybrid plant were similar to its pollen parent, golden camellia.

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Leaf morphological characters were investigated with the diallel analysis by using F₁'s among the five Hokkaido varieties. The additive gene effects predominated over the dominance effects in all characters. h (the total sum of the dominances of the loci) was significantly positive in the lengths of the second and third leaves, but was negative in the first leaf width. Two or more genes may affect to each character, as estimated with the one formula, (the maximum parent value - the minimum parent value)2/4D. Correlation coefficients among the characters indicated a trend that a short culm genotype had short, narrow and erect leaves, and vice versa.

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Proportion of hull weight to whole grain (hull content : hull weight/grain weight) is one of important traits for high yield in rice (Oryza sativa L.). Varietal difference of the hull content was associated with grain thickness and hull thickness. The varieties with low hull content obviously had thick grains and thin hulls. Hull content of 25 varieties ranged from 17.1% to 22.1%Most of Indica varieties had higher hull content than standard Japonica varieties. Average of hull content of 20 Indica varieties was 2.3% higher than that of 5 Japonica varieties because Indica varieties had thicker hulls. However, it was found that 2 Indica varieties (UPR254-85 and IET1785) had same low hull content as that of Japonica varieties.

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