To investigate the expression of a waxy gene in O. glaberrima, chemical and physical properties of the endosperm starch were examined employing waxy and non-waxy cytoplasmic substitution lines that have the nucleus of O. glaberrima and the cytoplasm of O. sativa, a waxy O. glaberrima line having a waxy gene derived from O. sativa and an induced waxy mutant of O. glaberrima. The endosperm starch lacks amylose in three lines tested, namely the waxy O. glaberrima line having a waxy gene derived from the Japanese cultivar of O. sativa, the induced waxy mutant of O. glaberrima and the waxy O, glaberrima line with both the cytoplasm and waxy gene derived form the Japanese cultivar of O. sativa. However, the ratio of the amount of short to long chain in the amylopectin seems to be affected by the nuclear genes, with the exception of a waxy gene. A waxy gene seems to have no effect on the gelatinization characteristics of the starch. Thus, these characteristics of the starch seem to be determined by nuclear genetic background except for a waxy gene, whereas cytoplasms seem to have no effect on both elution patterns of debranched starch and gelatinization characteristics of endosperm starch. A waxy gene seems simply to reduce the amylose content of endosperm starch without affecting other characteristics of starch.

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The ovary slice culture method was successfully applied to obtain interspecific hvbrids of Lilium. Ovary disks of Lilium longiflorum were inoculated on a modified MS medium (HAYASHI et al. 1986) on the 40th day after intrastylar pollination with 4 cultivarieties of L, × elegance. A total of 92 ovules germinated in all the combinations, and the regenerated plantlets were found to be interspecific hvbrids based on chromosome studies.

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We reported previously that Indonesian rice varieties belonging to the so-called Javanica varieties could be classified into some different types in respect to F₁-sterility relationships with a set of Indica and Japonica testers. Firstly, in this study, we observed that the F₁ Plants between these different types were fertile with a few exceptions. Secondly, to look into the genetic basis of the sterility of the F₁ hybrids between a variety, Penuh Baru II and Indica or Japonica testers, we made threevarietal crosses involving Penuh Baru II, a “wide-compatibility” variety Ketan Nangka, and IR 36 or IR 50 (Indica tester). The progeny of the three-varietal crosses showed an association of spikelet fertility with certain gene markers. The segregation pattern for the spikelet fertility was explained by a model of one-locus allelic interaction. It was postulated that the Japonica tester as well as Penuh Baru II have the same allele S-5^j while the Indica tester has S-5ⁱ at the S-5 locus belonging to linkage group I, and that female gamates with S-5^j are aborted in plants with the genotype of S-5ⁱ/S-5^j. Ketan Nangka was found to have a wide-compatibility allele S-5ⁿ which does not confer sterility in combination with other alleles. The F₁ sterility of Penuh Baru II with Japonica tester appeared to be controlled by sterility genes other than those at S-5 locus. The wide-compatibility gene S-5ⁿ can be usefull in the breedig of Indica-Japonica crosses and also in developing Indica-Japonica F₁ varieties.

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Radiosensitivity of barley varieties as expressed by callus growth was examined after exposure of seeds to gamma-rays and transfer of mature embryos detached from seeds or whole seeds onto medium for the initiation and growth of callus. Marked differences in the value of D₅0 about 7-fold at maximum were observed among the varieties employed (Figs. 1 a and b). Particularly all the naked varieties used showed much lower values of D₅0s than the covered ones (Table 1). These results correspond to the level of radiosensitivity expressed by seedling growth after seed irradiation (Figs. 2, 3). A major gene (rs) on chromosome I which has recently been found to control the latter radiosensitivity seemed to exert its effect on the radiosensitivity measured by the callus growth. When calli initiated from seeds were irradiated three days after inoculation on agar medium, the value of D₅0 for callus growth decreased markedly from 44 kR in seed irradiation to 5 kR in callus irradiation for the covered variety, while the change in the value of D₅0 was slight, changing from 7 to 3 kR for the naked variety. The difference in the value of D₅0 was not large, but still significant (Figs. 4 a, 4 b). The relationship between the value of D₅0 for seedling growth in the case of seed and seedling irradiation and that of D₅0 for callus growth after callus irradiation varied considerably with the varieties.

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Embryo sensitivity to abscisic acid (ABA) of wheat cultivars “Lancer”, “Horoshirl”, and “Lewis”, which showed different sprouting resistance, was estimated In the initial stage of germination in terms of lipase-esterase activity detected by the fluorescein dibutyrate (FDB) method. Lipase-esterase activity increased in the endosperm adjacent to the epithelium of the scutellum and expanded to the inner area of the endosperm as germination proceeded. Seed germination and lipase-esterase synthesis of sproutingresistant “Lancer” were inhibited by ABA, while sprouting-susceptible “Lewis” was not suppressed in terms of either germination or enzyme synthesis by ABA. In moderately reslstant “Horoshiri”, germination was suppressed, but its lipase-esterase synthesis was not suppressed by ABA Seed of “Lancer” that had been stored for six months after harvest and had lost their dormancy still maintained embryo sensitivity to ABA. The experiments showed that embryo sensitivity to ABA can be estimated with the FDB method by treating whole seeds with ABA, after seeds have lost their dormancy.

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Genetic segregations of a marker locus responsible for red hypocotyl-color (R) and five independently-inherited enzyme-coding loci (Got-2. Lap. Gdh-2, Aph-1, Px-2) in the backcrossed progeny between B. vulgaris or B. maritima and B. macrocarpa were examined. Transmission of the B. macrocarpa alleles into the progeny was strongly dependent on whether F₁ hybrids were used as male or female parents in the backcrosses. Distorted segregations occurred in most of the markers when F₁ hybrids were used as male parents ; consistant deviations from the expected 1 : 1 ratio resulted from an excess of the B. macrocarpa alleles for a linked pair, R and Got-2, and a deficiency of the alleles for Lap and Gdh-2. Anomalous segregations also occurred for Aph-1 and Px-2, depending on parental strains used in the backcrosses. In contrast to these results, the expected Mendelian ratio was observed in all the markers except for R when F₁ hybrids were used as female parents. Because of the lowering of the pollen and seed fertilities in the F₁ hybrids and no zygotic lethality after germination in the backcrossed progeny, the aberrant ratios appeared to arise from linkage of the markers with genetic factors affecting gametogenesis, pollen functions and embryo development in the hybrids. Of the six markers, Lap was found to be linked to a gene responsible for an abortion of a part of pollen grains. In addition to the disrupted monogenic ratio, two-locus segregations often deviated from the expected ratios from random association of the alleles. It was thus suggested that the causal factors of distortions might have complex multifactorial and multi-chromosomal genetic origins.

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Interspecific hybrids between N. trigonophylla (2n=24, ♀) and N. tabacum (2n=48, ♂) were obtained through in vitro culture of hybrid ovules. Hybrid plants were produced efficiently, when the medium conditions were suitable. All of the hybrid plants were morphologically uniform, cytologically stable and completely selfsterile. The pollen viabilities of the amphidiploid plants induced by colchicine treatments exceeded 90%, while viable seeds were obtained only from about 5% of the ovules.

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The glutelin seed storage protein from 80 cultivars of rice (Oryza sativa L.) was analysed by SDS-polyacrylamide gel electrophoresis and 2-dimensional polyacrylamide gel electrophoresis. A deletion of one of the glutelin a subunits, α-3, was found in 16 cultivars. All of these cultivars which show this deletion, belong to the Indica type of rice, not the Japonica type. This suggests that there might be a close relationship between the α-3 subunit deletion and the differentiation or distrrbution of rice.

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Thirty two collections belonging to 27 corn races native to Mexico, Guatemala, Cuba G. R., Dominican Rep., Ecuador, Colombia, Venezuela, Brazil, and Uruguay, were cultivated in 1978 and 1979 at the Experiment Farm (34°34' N, 135°30' E) of the University of Osaka Prefecture, Japan. The purpose of this study was to classify the races by the traits appeared under environments quite different to those of the native habitats, and to estimate relationships of the traits to the native geographical locations of every races used. The races originated from lower latitude exhibited later flowering habit, accompanying by the increase in the number of nodes of stalk, tlle reduction in the number of effective ears on a main stalk which set more than one kernel (Tables 1 and 3), and some modifications of plant parts (Tables, 4, 5 and 6). These trends, however, appeared differently with different races. Characters to tell races included, in particular, growth habits as earliness, plant height, the number of effective ears per main stalk, and the number of tillers per plant. Being examined by the growth habit and geographical location of native habitat, all the races were classified into five groups, each of which have originated from any one of the following geographical regions : I. Atlantic Coast (from Uruguay to the West Indies, including the coastal provinces of Brazil, Venezuela, and the Atlantic side of Colombia), II. Mexican Lowland (lowlands of Mexico including Yucatan Peninsula), III. Mexican Highland (the Central Mesa of Mexico), IV. Highland (highlands from northern Andes up to southern Mexico), V. Colombian and Ecuadorian Pacific Coast. The pattern of growth response to the environment in Osaka was basically similar among the races of the same group, even if their native habitats were distant apart and different in climate, suggesting that the races from the same region possessed related genotypes for expressing the growth habit in Osaka. Published data on the morphological traits and geographical locations of the native races gathered from the Latin America by many authors so far were examined, and the distribution ranges of many families of related races were estimated. These considerations gave the conclusion that each of the five regions is the zone where related races have become differentiated, i.e. the center of racial diffrentiation. The five regions were compared with the primary and secondary centers of maize presented by BRANDOLINI (1970, 1971), and some disagreements found between the two were also discussed.

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Seventy five cultivars were evaluated for their resistance to a virulent strain of soybean mosaic virus (SMV-C) spreading in the central part of Japan. Reactions of trifoliolate leaves of the cultivars to the C strain were classified into the following three types ; no symptoms (resistant : R), necrotic spot symptoms (NS : Fig. 3) and typical mosaic sylriptoms (M). Three resistant cultivars (R), two cultivars with necrotic spots (NS) and seven susceptible ones (M) were used to study the mode of inheritance of the resistance by artificial inoculation tests conducted in the greenhouse. F₁ plants of crosses between three resistant and susceptible cultivars (R-S) showed necrotic spots or did not exhibit symptoms, and the F₂ plants were classified into three types in the same way as the cultivars (Table 1). If it is considered that the NS plants have the same type of resistance as the resistant plants, all the crosses fit to the ratio 3 resistant : 1 mosaic symptoms, indicating that the resistance is controlled by a single dominant gene. However in the case of the two crosses using “Tousan 140” as resistant cultivar, F₂ plants fitted well to the ratio 1 no symptoms : 2 NS : 1 mosaic symptoms. All the F₁ plants of these crosses corresponded to the NS group, and the F₃ plants which were derived from F₂ plants with necrotic spot symptoms segregated into the ratio 3 resistant : 1 mosaic symptoms. The backcross populations between susceptible cultivars and F₁ plants segregated into the ratio 1 necrotic symptoms : 1 mosaic symptoms. These results suggest that the plants with the NS symptoms show on heteroallelic phenotypes in the case of “Tousan 140”. Thus the resistant cultivars are considered to have one totally or partially dominant resistance gene. Among the crosses between resistant cultivars (R-R), in two crosses the F₂ populations segregated into the ratio 15 resistant : 1 mosaic symptoms while in another cross the populations did not exhibit symptoms (table 2). These data indicate that there are two kinds of independent resistance genes. On the other hand, the R-NS crosses segregsted into the ratio 15 resistant : 1 mosaic symptoms, and the S-NS crosses segregated into the ratio 3 resistant : 1 mosaic symptoms (table 3). These data indicate that the cultivars with necrotic spot symptoms (NS) have a dominant resistance gene which is inherited independently of the two kinds of resistance genes mentioned above. “Raiden” which was bred in Japan is considered to be the source of the resistance gene Rsv2 (BUZZEL and TU 1984), but is susceptible to the C strain. So it is assumed that the three resistant cultivars may have different gene from Rsv2. The relationship between the genes of these cultivars and that of “PI 96983” (gene symbol Rsv : KIIHL and HARTWIG 1979) and “PI 486.355” which was reported by LIM (1985) could not be verified in thls study. Since the reaction of “Ogden” was the same as that of “Tousan 122” and “Dorchsoy 31”, cultivars with NS symptoms such as “Tousan 122” may have the same resistance gene symbolyzed by rsv^t (KIIHL and HARTWIG 1979). It is concluded that there are at least three kinds of independent resistance genes to the C strain.

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Rice starch consists of amylose and amylopectin, and the stickiness of cooked rice largely depends on the amylose content. In Japan, rice with a relatively low amylose content is preferred. However, rice produced in Hokkaido generally contains more amylose than that produced in southern Japan. Recently, it was reported that the amylose content of the rice endosperm was influenced by the temperature during the early ripening period. To determine the extent of the changes in the amylose content, 11 rice varieties with early maturity were grown at Iwamizawa (central Hokkaido) and at Kurashiki (southern Honshu) in the 1985 season. The same varieties were also grown in phytotrons in which the temperature was set at 18±5 and 28±5°C throught the ripening period. The varieties headed at Iwamizawa in early August and at Kurashiki in late July. Average temperature during 20 days after heading was ca. 25 and 29°C, respectively. The amylose content of polised grains was estimated from the blue value measured at 600 nm. The varietal means of amylose content ranged from 18.3% in the variety Shimahikari (a high quality variety produced in Hokkaido) to 21.1% in the variety Tomoyutaka (Table 1). Varietal variation was significant at the 0.1% level in the Kurashiki field experiment where 12 plants of each variely were examined (Table 2). The environmental means ranged from 17.0% in the Kurashiki field to 21.7% in the 18°C-phytotron, and the amylose content showed a close relation to the temperature during the early ripening period (Fig. 1). As the regression of the arnylose content on the temperature was not linear, the response of the amylose content to the temperature was estimated by the regression of the amylose content of each sample on the environmental mean (Fig.2). The regression coefficient of the amylose content on the environmental mean ranged from 0.69 in the variety Matsumae to l.48 in the variety Hayakogane. Varietal variation of the regression coefficient corresponded to the 5-10% level (Table 3). The eleven varieties examined were scattered by the mean of the amylose content and the response to temperature (Fig. 3). Hayakogane showed a low mean and a strong response, whereas Tomoyutaka showed a high mean and a weak response. In Hokkaido, where the temperature during the ripening period is low and unstable, varieties with a low and constant amylose content like Shimahikari are desirable.

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Seven two-rowed barley cultivars in Japan were compared for their ability for embryoid formation and plant regeneration in anther culture. Ability for embryoid formation varied among the genotypes from 0 to 18.7 embryoids per 100 anthers. Embryoids were generated only in the upper lobes of anthers when each anther was vertically placed with a single lobe in contact with the medium (Fig.1). Green plants were induced from embryoids in three cultivars “Haruna Nijo”, “Saikai Kawa 38” and “Satsukibare”. The average ratio of green to albino plants was 1 : 8.5.

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Kidney beans contain a water-soluble substance which strongly inhibits the larval growth of azuki bean weevil. The substance has been purified by fractionation methods involving dialysis, precipitation with ammonium sulfate, and chromatographies with DEAE-Sephacel and Con A-Sepharose. The inhibitory activity was bioassyed using the artificial beans incorporating the fractionated materials after lyophilizing into the azuki bean meal. The purified substance, which is one of glycoproteins having the molecular weight of about 100, 000, showed inhibitory activity on α-amylase. When the α-amylase inhibitor was incorporated at 0.2-0.5% into the artificial beans, the larvae of the weevil could not develop by feeding them and died. The results obtained here show that the α-amylase inhibitor is responsible for the protection of kidney beans against the attack of azuki bean weevil.

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In order to develop an efficient regeneration system for saffron breeding, callus culture of saffron was investigated to promote its efficiency by the use of phytohormones combined with a suitable range of temperature for culture. Callus induction was carried out on MS medium (MURASHIGE and SKOOG, 1962) with 2, 4-D(D) and Zeatin(Z), after sterilization of the bulbs of commercial origin (Sakata Seed Corp.) by standard methods. The callus was subcultured three times to obtain a complete dedifferentiation. In one method, the callus obtained after the 3-rd transfer was cultured by gyrating it after transfer to MS liquid medium supplemented with 1 mg/l, 2, 4-D. After 7∼10 days of culture, the callus crumbled and developed into a small spherical organ-like nodule. When this nodule was cultured continuously, it was able to grow, but after transfer onto MS medium supplemented with 0.1mg/l 1-naphthaleneacetic acid (N 0.1) and 1.0 mg/l 6-benzylaminopurine (BA 1) or MS (N 1, BA 3), the nodule enlarged irrespective of the conditions of the culture (liquid or solid). Shoots regenerated on thc surface of the enlarged tissues after 3 months of culture on solid medium with similar composition at 25°C. These shoots were transplanted and cultured under aseptic conditions. On the other hand, the callus was cultured on the MS (N 0.1, BA 1) medium at 15°C and 20°C, it became an organogenetic tissue with a smooth surface after 3 months. Then this tissue turned green and regenerated shoots or rooted partially.

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