A fluorescent character was found in the progenies of annual ryegrass-tall fescue hybrids. Fluorescent percentage, rust resistance, and NVI were examined in the first-generation self, open-pollination, and polycross progenies of five parent plants. Fluorescence percentage of progenies of some parents showed th. at fluorence is controlled by a single dominant gene. However, results of the progeny of other lines suggested the infiuence of modifying genes. Significant differences were not obtained between fiuorescent and nonfluorescent plants for rust resistance and NVI; however, difEerences among lines for rust resistance were significant.

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Annual multigerm and monogerm pollen restorer lines (P-MM and P-mm), which, were isolated from the cross combination of the annual multigerm (cytoplasmic) male sterile and biennial monogerm strain both introduced from USA, were crossed with annual multigerm and monogerm male sterile lines (TA-1-MS and TA-2-MS). F₁ and F₂ populations of the cross combination of TA-2-MSXP-mm and TA-1-MSXP-MM were grown and checked for two characters, male sterility and monogermity, at the Yamagata University (Tsuruoka) during the summer of 1972, 1973 and 1974. This study confirmed that monogermity was governed by recessive monogenic inheritance, although monogerm plants in F₂ Segregation were slightly fewer than the expected value. Pollen parent lines and F₁ populations segregated no complete sterile plants, but considerably produced semisterile plants besides complete fertile plants. The appearance of semi-sterile types was attributable to effects of environment and minor modifying genes in the interaction with two major genes. The mode of inheritance applied to the pollen parent lines used in this study was as follows : Using the Owen's gene scheme, complete sterility and semi-sterility are governed by only X gene locus and complete sterility is induced by the single recessive condition, whereas pollen fertility is controlled by the complementary effect of X and Z genes. This will support Owen's original hypothesis. In addition to this gene scheme, minor modifying genes accelarate or suppress male sterility. Linkage relation between one pollen restorer gene, X, and monogerm gene was not recognized in this cross combinations. In linkage relation between the other pollen restorer gene, Z, and monogerm gene, there were some cases of the significant inter-action between the two genes, which was responsible for segregations as if the F₂ had been in a coupling phase of linkage notwithstanding a repulsion phase. This suggests that Z gene locus was independent of monogerm gene.

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The high protein property of a Japanese rice variety "Fukunishiki" was studied geneti cally and genealogically. Inheritance of the high protein property was investigated by the use of the F₂ hybrid population derived from the cross of the high protein variety "Fukunlshlkl" wlth a low protein one "Fujimlnori". The F₂ population mean as well as the F₁ mean fell on between the low protein parent and the mid-parent values. A monomodal, symmetrical distribution was observed in the F₂ segregation of protein content (Fig. 1). The broadsense heritability of protein content was computed based on the genetic variance of the F₂ hybrid population and the estimated value 0.45 was obtained. The F₂ to F₃ and F₃ to F₄ parent-offspring correlations for protein content were 0. 551 and 0. 709 respectively, both of which were statistically slgnificant at the 1% Ievel (Fig. 3, and Fig. 4). Regarding to the relatios between the protein content and the other agronomic traits, negative correlations were predominantly observed in F₂ through F₄ generations derived from the above-mentioned cross. Early, short-statued, and poor-yielding segregants tended to be rich in protein (Tabe 1).

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The male sterile T. timopheevi cytoplasm was introduced by successive backcrosses intcp 20 Japanese and 13 American cultivars of common wheat. In advanced backcross generations, all but four cultivars turned out to be complete or nearly complete male-steriles. Junrei-Komugi, and Norin 50, 52 and 69 were found to be carriers of a weak fertility restoring gene(s). From an investigation of their pedigrees, Junrei-Komugi, and Norin 50 and 52 were assumed to have received their gene(s) from their common ancestor, Shinchunaga, while Norin 69 appeared to have a different gene(s). Most male sterile lines of the other cultivars expressed male sterility constantly in different years (1969-1975), and in different localities (six locations from Kyushu ta Hokkaido in Japan). However, a few lines recovered selfed seed fertilities higher than 20% in Fukuyama in Chugoku District, where the environment seems to be shallow sterile for these lines. The out-crossing ability of all these male sterile lines was tested, using their seed setting rates under open-pollination. Male sterile lines of Aoba-Komugi, Bledsoe, and Lemhi 53 are considered to be good cross-fertilizers, while Karnvor, White Federation, Kokeshi-Komugi, Idaed 59, Fujimi- and Mikuni-Komugi are thought to be poor cross-fertilizers, the remainder being intermediate. With proper arrangement of pollinator rows, the male sterile lines tested showed a 51-83 seed-set by out-cross, which seems to be sufficient to guarantee hybrid seed production in Japan.

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In order to determine the influence of washing temperature on mutagenic effects of EMS remaining in seeds after soaking-treatment, dry seeds of two rlce strains, cultivar Gimbozu and an albina-segregating strain derived from Gimbozu, Ivere soaked in EMS solution (0.8% or 0.9%) under four diffent temperatures (0'C-30'C) and washed with water at four degrees of temperature (10'C-40'C). As to Girnbozu, considerable infiuences of the temperature during washing were observed on injury of M₁ characters, such as germination rate, seedling height and seed fertility, and on frequency of mutations in chlorophyll, heading date and culm length in M₂ generation. Mutatino frequency in heading date and culm length was expressed with the percentage of M₂ plants falling outside the variation range of original variety defined with a certain confidence limit (cti), that is, with the percentage of those in the critical region of a=0.01. These effects remarkably depended not only upon washing temperature but also upon soaking temperature. As to the albina-segregating strain also, the same mutagenic effects of washing temperature as seen in Gimbozu were recognized on the frequency of somatic chlorophyll mutations induced on M1 plants. This suggests that somatic chlorophyll mutations are available for early determination of the mutagenic effect of some mutagen.

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Cytoplasmic male-sterility of corn is related to altered functions of mitochondria. To substantiate this hypothesis, we studied the activities of two mitochondrial enzymes, cytochrome oxidase (cyt. oxidase) and malate dehydrogenase (MDH), in anthers and flag leaves of normal and male-sterile lines. Corn cultivar WF9 with normal (N) cytoplasm and its isogenic lines with male-sterile (MS) T-. S- and C-cytoplasms were used for experiments. Developing tassels in flag leaves were sampled from the plants. A portion of the tassel was fixed in acetic alcohol for microscopic examination of the stage of pollen development. A known weight of anthers was collected from another portion of the tassel. It was then homogenized in a buffered medium containing sucrose, and centrifuged to yield three fractions; "precipitate fraction", "mltochondnal fraction" and "supernatant fraction". Cyt. oxidase and MDH, activities of each fraction were assayed, and activity values per gram of fresh sample were calculated.

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Changes of six quantitative characters in the trisomic rice plants identified by the morphological features were studied by the principal component analysis. The applica-tion of this analysis proved to be effective in gl-ouping the respective single trisomics, double trisomics and disomics. Lines identified as different types of the trisomics com-posed different groups in the scatter diagram allowing a little overlapping. Disomic plants segregated from the progenies of trisomics, which had been derived from four different cultivars, tended to form different groups, showing: the difference in their genetic backgrounds. Sorne types of double trisomics under investigation demonstrated to have been typically changed to the direction synthesized by the characters of two single trisomics with respective chromosomes. This fact indicates that the addition of an extra chromosome has an independent specific effect on the expression of character's not only of single but also of double trisomic plants.

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