Studies on the self-incompatibility of Petunia hybrida in excised-style culture. An attempt at improving a technique in excised-style culture

Summary A technique of excised-style culture was developed. In twelve compatible combinations of pollen and style, a correlation was found between the number of pollen tubes protruding from the style and the number of mature seeds formed in vivo. This suggests that the technique of improving excised-style culture is effective not only for studying the interactions between style and pollen tubes during tube growth, but also for predicting the production of seeds in vivo.     

Forestomach developmental failure in an 11-month-old Japanese Black steer with severely retarded growth and chronic ruminal tympany

This study reports findings from the pathological examination of the forestomach of an 11-month-old Japanese Black steer with severely retarded growth (41% of expected weight) and chronic ruminal tympany. The ruminal papillae were weakly formed (0.3–0.5 cm long) and unevenly distributed. The cellulae and cristae reticuli were underdeveloped; the cristae were 0.4–0.7 cm in height and milky white. The keratinized layer in the stratified squamous epithelium was thickened. Ruminal pH was 5.25, and ruminal volatile fatty acid concentration was 11.7 mM. The steer’s severely retarded growth was considered to be caused by malnutrition due to developmental and functional failure of the forestomach.     

In vitro growth of bovine oocytes in oocyte-cumulus cell complexes and the effect of follicle stimulating hormone on the growth of oocytes

Several successful in vitro culture experiments have used oocyte-cumulus cell-mural granulosa cell complexes (OCGCs) from early antral follicles (0.5–0.7 mm) for the growth of bovine oocytes. However, in studies related to in vitro oocyte maturation and in vitro embryo production, oocyte-cumulus cell complexes (OCCs) that have no mural granulosa cells have been widely used instead of OCGCs. The purpose of this study was to determine whether cumulus cells alone support oocyte growth. First, OCCs and OCGCs were cultured in vitro for 14 days to compare the integrity of the complexes as well as antrum formation. After 14 days, the diameter and meiotic competence of oocytes in OCCs and OCGCs were examined. Oocytes in OCCs grew fully and acquired meiotic competence similar to OCGCs, whereas antrum formation occurred later in OCCs as compared to OCGCs. Subsequently, the effects of follicle stimulating hormone (FSH) on in vitro growth of OCCs were examined for 14 days. When FSH was added to the culture medium, OCCs formed antrum-like structures one day earlier than those cultured without FSH. Oocytes cultured with 1 mIU/ml FSH grew fully and acquired meiotic competence. In contrast, when oocytes were cultured in media containing high concentrations of FSH, some of the OCCs collapsed and the number of degenerated oocytes increased. In conclusion, bovine oocytes in OCCs grow and acquire meiotic competence similar to OCGCs and, 1 mIU/ml FSH supports the development of OCCs and oocyte growth as observed in our culture system.     

TOTAL POTASSIUM IN SOILS BY RADIOACTIVITY MEASUREMENTS

The beta- and gamma-analysis methods were fully tested on nineteen British soils; ‘marker’ gamma photo-peaks of daughter-elements were used for estimating Th and U, and the 1.46 MeV^?40K photo-peak for K. The photo-peaks for Th and U that give values for the K contents of the soil closest to the chemically determined values are ²⁰⁸Tl(ThC″)–2.615 MeV and ²¹⁴Bi(RaC)+–0.609 MeV respecively. Reasonable values for the Th content of these soils are obtained by this method, but U contents seem to be considerably overestimated.     

Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2‐11#2 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low‐marbled and high‐marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the ribosomal protein L27a (RPL27A) gene containing the c2‐11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker‐assisted selection to increase the levels of marbling in Japanese Black beef cattle.     

Total selenium content of agricultural soils in Japan

To evaluate the selenium (Se) level in agricultural soils in Japan and to investigate its determining factors, 180 soil samples were collected from the surface layer of paddy or upland fields in Japan and their total Se contents were determined. Finely ground soil (50 mg) was wet-digested with HNO₃ and HClO₄ solution and the released Se was reduced to Se(IV). The concentration of Se(IV) was then determined by high-performance liquid chromatography with a fluorescence detector after treatment with 2,3-diaminonaphthalene and extraction with cyclohexane. The total Se content ranged from 0.05 to 2.80 mg kg⁻¹ with geometric and arithmetic means of 0.43 and 0.51 mg kg⁻¹, respectively. The overall data showed a log-normal distribution. In terms of soil type, volcanic soils and peat soils had relatively high Se content and regosols and gray lowland soils had relatively low Se content. In terms of land use, upland soils had significantly higher Se content than paddy soils. Among regions, soils in the Kanto, Tohoku, Hokkaido and Kyushu regions had relatively high content. The total Se content had a significant positive correlation with the organic carbon content ( P  < 0.01) and the equation for the estimation of total Se content with organic carbon suggested that on average approximately 48% (0.24 mg kg⁻¹) of the total Se was in inorganic forms and approximately 52% (0.25 mg kg⁻¹) was in organic forms. Soil pH, on the contrary, did not show a significant relationship with the total Se content. In conclusion, the organic matter content, in combination with volcanic materials, was the main determining factor of the total Se content of agricultural soils in Japan.     

高丹草品种主要农艺性状的比较研究

在日本北海道气候条件下,对6个高丹草品种的生长适应性及主要农艺特性进行了研究.田间观察6个品种生长势强,均能适应当地气候条件,但在生物学及生产性能方面品种间存在差异.发育前期及后期生长速度快的品种为Mnqsi No.1和Mnqsi No.2,最慢的品种为Greensorgo和Raceysorgo,品种Grenn-A在发育后期生长较快,Sudancums次之.Greensorgo和Raceysorgo为早熟型品种,Mnqsi No.1、Mnqsi No.2和Green-A均为晚熟型品种,Sudancums为中熟型品种.株高、鲜草产量顺次为:Mnqsi No.1＞Green-A＞Mnqsi No.2＞Sudancums＞Greensorgo＞Raceysorgo;茎粗、茎叶比顺次为:Green-A＞Sudancums＞Greensorgo Mnqsi No.2＞Raceysorgo＞Mnqsi No.1;分蘖能力顺次为:Mnqsi No.2＞Mnqsi No.1＞Sudancums＞Raceysorgo＞Green-A Greensorgo.穗型及叶片特征品种间有一定差异.     

Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release in bulbs of Lilium rubellum

Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release of lily bulbs of Lilium rubellum were investigated. Shoot emergence and flowering of the bulbs stored for 14 weeks at 4 °C occurred more synchronously, and the time span from first to last flower in the plants was shorter than those of bulbs stored for 10 weeks at 4 °C. Longer duration of bulb storage showed accelerating effects of increasing leaf number and stem length but negatively affected flower size. Flower number per plant was not much influenced by bulb storage duration. Concentration of endogenous abscisic acid (ABA) level in the bulbs during bulb storage decreased as storage duration increased, and it remained at a constant level after being stored for 10 weeks. This result suggests that the decrease in the endogenous ABA level during bulb storage is correlated with dormancy-release. Concentrations of soluble sugars also changed during bulb cold storage. Sucrose concentration increased as the chilling term increased to 10 weeks but decreased afterward. Glucose and fructose increased from the beginning of chilling to the end of a 14-week cold storage.