In a previous paper, the authors reported on the affinity between the lines derived from the intersubspecific hybrid of rice, Oryza sativa L., and their original parents. In short, most of these lines were thought to have returned to Japonica type parent, but some lines differed from their original parents and seemed to become a new type. To elucidate it more thoroughly, the authors produced the F₁ hybrids between the 17 lines chosen at random from the progeny of the intersubspecific hybrid and the ecotypes of rice plant, Japanese rice, aus, aman, bulu, tjereh and boro, and investigated their seed fertilities. The results of the investigation lines were divided into two froups, “a” and “b”, according to sexual affinity between thses lines and the ecotypes. The lines of “a” group showed the highest affinity to Japanese rice, and moreover, the affinity to other ecotypes were similar to that between Japanese rice and other ecotypes. The authors considered form these results that the lines belonging to “a” group had returned to Japonica type parent. Three lines of “b” group were, on the other hand, thought to belong to intermediate tyoe grouped by morinaga, as they showed considerably high affinity to all ecotypes. They, however, differed from one another, and also differed from aus and bulu which were typical intermediate type. It gives us much interest in understanding the phylogenetic differentiation of cultivated rice varieties that the intermediate type was produced experimentally from Japonica-Indica hybrid.

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With an aim to obtain a good source of resistance to leafrust of wheats, the amphidiploid was synthesized between Triticum Timopheeve Zhuk. (2n=28, AAGG) and Agropyron elongatum (Host.) Beauv. (2n=14, ??) by treation the F₁ seeds with 0.05% colchicine. As all of the F₁ seeds obtained were subjected to the colchicine treatment, the cytogenetic studies on the untreated F₁ plant were not carried out. The modal chromosome configuration of the amphidiploid was 20_II+2_I. The amphidiploid is similar morpjologically to the amphidiploid, Timopheevi-squarrosa, but its spikes are somewhat longer than the latter and the spike-density is characteristically lax near the neck of asoike. The manner of disarticulation of spikes is “wedge-type” dominantly. The seed fertiity is considerably high, showing 74% in self pollination. Not only does this new amphidiploid show the high sexual compatibililies with T. Timopheevi, one of the parents used in its synthesis, but also easily crosses with many varieities of common wheat. But it showed the lack of crossability with the other parent, AG.elongatum. This new wheat is immune to many races of Puccinia triticina. Terefore, it will be a useful material in breeding of leaf-rust resistant varieties of wheat. One of the aneuploids discobered, having 2n=40, was assumed to be the triple F₁ hybrid between Timopheevi-elongatum and Ag. junceum (2n=42).

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The biological effects of fhemecals combined with the X-rays or neutrons on rice seeds were compared with the irradiation of seeds by X-ray or thermal neutron only and the treatment of seeds by Ca(NO₃)₂, Colchicine, Diepoxybutane or β-propiolactone only. (c.f. Table 1, 2) Ca(NO₃)₂ which was used as the neutron capture, gave only a slight effect on growth and fertility of M₁-plants and decreased the frequency of chlorophyll mutation in M₂ generation when seeds were treated whit it just before the irradiation by neutron. Post-treatment of seeds by Colchicine increased the fertility of M₁-plant compared with the single irradiation, but gave no effect on mutation frequency when combined with X-rays, and decreased the frequency when combined with neutrons. Diepoxybutane and β-propiolactone, which are already known as mutagenic substances, had high effect on germination and survival of M₁-plants in both the cases ; i.e. single application of chemicals or combined with radiation. However, there increased fertility and mutation frequency treated materials when thses chemicals were used as posttreatment substances of X-rays, but there seemde no effect on mutation frequency when they were conbined with neutrons. According to this result, these mutagenic chemicals seem to have some chemical action on the process of recovering the breakage of chromosome caused by X-rays. On the other hand, no different spectra of chlorophyll mutations was obtained by a comparison of the effect of radiation alone with the effect of chemicals combined with radiation. (c. f. Table 3)

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There are two varieties, Shizuoka and Kochi of Edgeworthia papyrifera in Japan. The are easily identified with their difference in certain characters. It is especially noted that the Kochi variety is highly sterile in self and free pollination. However F₁ hybrid were easily obtained in reciprocal crosses between Kochi and Shizuoka varieties. From this fact it can be assumed that the high sterility of the Koch variety is due to (1) the self-sterility found generally in Edgeworthia, and (2) that its population originated by a vegetative propagation of or a few original plants. A comparative study was made with some morphological characters i n the hybrids and their parents (Tables 1-6). Meiotic pairing of chromosomes in PMC-s were also extensively observed in the hybrids and their parents. In each of them 18 bivalents were normally formed in most cases, but the formation of one to two quadlrivalents or the failure of chromosome pairing in a few bivalents were occasionally observed. All these data obtained so far suggest strongly that Kochi and Shizuoka varieties show nothing but genic differences found in just the usual varieties.

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Hybrid vigor and variability in F₁ hybrid on the traits of the mammary growth response to estrogen and the body weight in mice were studied on 4 inbred strains and F₁ hybrid between them. Strains bc and C (undergone full-sib mating for mcre than 25 generations) and KA and KB mice (undergone full-sib mation gor 12 generations), which have been selected for mammary growth response, were used in this study. All tested mice were recieved total dose of 12.5 I.U. of synthetic estrogen from 20 days of age. They were killed at 35 days and their third thoracic mammary glands were removed from the skin to prepare them by the whole mount method. The mammary growth response was expressed by the mammary duct area. Body weight were measured at birth, 12 days, 20 days and 35 days of age. In these characters, the potence ration ((F₁-Pm)/|P-Pm|) of F₁ hybrid, which indicated an effect of heterosis, were calculated. The presence of maternal influence was examined. Variations of body weight and mammary growth response were compared between inbred strains and F₁ hybrid between them. The results obtained are briefly summarized in folllowing: (1)The potence rations of F₁ hybrids were more than 1 in moset cases, and accordingly high heterosis in these characters seemde to be present in F₁ hybrids. On the body weight, the values were the smallest at 12 days and thereafter increased gradually with advancing stages. (2)In mammary growth response the potence ratio of F₁ hybrid between unselected strain × sekected was the smallest in both sexes. But the value of mammary growth response of selected × selected was the highest, and that of selected × unselected was next and that of unselected × unselected was the lowest. (3)Maternal influence on body weight was significant at 5% level at 35 days of age only. Proportion of the magnitude to total variance was considerably large at birth, and thereafter decrease with advancing stages. That of mammary growth response was significant at 5% level in female but not in male. (4)In body weight at any stage and mammary growth resoinse, F₁ hybrid proved to be more unifrom than inbred strains. (5)Cariability of mammary growth response in F₁ hybrid of selected × selected was the most unifrom, that of unselected × was next and that of unselected × unselected was the largest in both sexes. (6)Close relationship was seen between mammary growth response and body weight at 35 days of age within each inbred strain or F₁ hybreid, but no relationship was seen inter inbred strain groups and inter F₁ hybred proups in both sexes. A suggestion with regard to obtaining animals with the smaller phenotypic variablity for a given trait, was put forward.

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Tricin and its glycosides together with chlorogenic acid occur in the leaf and grown colored awn in rice, but in the white awn, tricin alone occurs. Tricin and its glycosdie (Fraction B) are most widely destributed among the varieties examined. Chrysanthemin, (cyandidin 3-glucoside), keracyanin (cyanidin 3-rhamoglucoside), cyanin (cyanidin 3, 5-glucoside) and uliginosin (malvidin 3-galactoside) are identified in the anthocyanin pigments at different parts of the plant. They occur singly or co-occur at particulat colored parts. Uliginosin occurs only in the pericarp of purple colored grain of particular varieties. Uliginosin and chrysanthemin, also chrysanthemin and keracyanin co-occur respectively in the purple colored preicarp of grin in two and one varieties. Chrysanthemin and keracyanin co-occur in the leaf blade, sheath, glumes, apicules, awn and stigma of many varieties. Chrysanthemin, keracyanin and cyanin co-occur in the leaf sheath, and culm internodes of a particular variety.

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