Photoperiodic reaction of sexual and asexual reproduction in Fragaria chiloensis L. CHI-24-1 plants grown at various temperatures     

Tomohiro Yanagi  Takanori YachiNcbuyuki Okuda 《Scientia Horticulturae》2006

Floral initiation of a wild strawberry strain, Fragaria chiloensis CHI-24-1, is strongly induced by a 24 h day-length (DL) treatment for 40 days consisting of natural daylight and continuous lighting at night by an incandescent lamp. To use the characteristics of floral initiation in CHI-24-1 as a genetic resource for breeding of cultivated strawberries, the photoperiodic reactions of sexual and asexual reproductive growth under various temperature conditions should be clarified. For that purpose, we examined: (1) floral initiation, inflorescence emergence and runner production seasons of CHI-24-1 plants grown under natural climatic conditions in an open field at the Faculty of Agriculture, Kagawa University and (2) the effects of various DLs and temperatures on floral initiation and runner production of CHI-24-1 plants. When the CHI-24-1 plants were grown under natural conditions, the floral initiation, inflorescence emergence and runner production were observed, respectively, in late autumn, spring, and from spring to autumn. Floral initiation of CHI-24-1 plants was induced strongly by 24 h DL at mean temperatures greater than 20 °C. The maximum floral initiation rates were 90% in the parent plant and 94% in the daughter plants, which were linked by runners to the parent plant. The floral initiation of the daughter plants occurred under 20, 22, and 23 h DL at mean temperatures greater than 20 °C, but not for the parent plants. Floral initiation was induced in 100% of the parent plants by the 8 h DL and the lowest mean-temperature conditions. Results of those experiments indicated that CHI-24-1 was an absolute long day plant having critical DL of about 20 h at mean temperatures greater than 20 °C, even though it was a June-bearing strawberry plant. In addition, CHI-24-1 was a facultative short-day plant at mean temperatures of less than 15 °C.  相似文献   

Effects of meat species on the postprandial thermic effect in rats     

Jun‐ichi Wakamatsu  Ryoji Fujii  Kimikazu Yamaguchi  Syouhei Miyoshi  Takanori Nishimura  Akihito Hattori 《Animal Science Journal》2013,84(5):416-425

We examined animal species differences in the postprandial thermic effect of meat and investigated the postprandial thermic effect of mutton in rats. After intake of experimental diets containing each meat, body temperatures of rats fed mutton or venison were significantly higher than that of rats fed rabbit meat. After intake of experimental diets containing fractionized mutton, the body temperatures of rats fed diets containing lean mutton protein were higher than those of rats fed diets without lean mutton protein. In a two‐dimensional fluorescence difference gel electrophoresis study of brown adipose tissue, it was shown that the intake of mutton up‐regulated the expression of many signaling molecules that are involved in energy metabolism. The postprandial thermic effect of mutton seems to be due not to catecholamine and adrenocorticotropic hormone but to thyroid hormones. The results suggest that intake of lean mutton protein stimulates the secretion of thyroid hormones and facilitates energy metabolism in rats.  相似文献   

The pollutant loads from a paddy field watershed due to agricultural activity     

Hyungjun Lee  Takanori Masuda  Hiroshi Yasuda  Yoshihiko Hosoi 《Paddy and Water Environment》2014,12(4):439-448

Observations were performed in a small agricultural watershed for four consecutive irrigation periods in order to characterize fluctuations in the characteristics of pollutant runoff from paddy fields. During the puddling and rice-planting period and at the beginning of the mid-summer drainage period, both the pollutant concentrations and pollutant loadings of suspended solids, total nitrogen, and total phosphorus increased. In contrast, the pollutant net loading of total nitrogen was negative during the intermittent irrigation period. These results indicate that changes in the specific agricultural activities in the paddy fields cause temporal fluctuations of the pollutant runoff. Previous studies which focused on paddy fields have dealt with unit loading for entire irrigation period only. However, the unit loading for the entire irrigation period cannot take into account pollutant loading fluctuations due to differences in agricultural activity. Thus the unit loading of pollutant should be evaluated for each agricultural activity during the irrigation period.  相似文献   

Primary taste center in the goatfish of genus Parupeneus     

Masato Kirino  Takanori Ikenaga  Junzo Tsukahara  Charles Flamb  Sadao Kiyohara 《Fisheries Science》2006,72(3):461-468

ABSTRACT:   This study was carried out to obtain fundamental information on the morphology of the primary taste center in the goatfish of genus Parupeneus. The primary taste center includes a dorsal facial lobe (dFL), ventral facial lobe (vFL) and vagal lobe (VL). The dFL is extraordinarily developed rostrocaudally to occupy the dorsal surface of the medulla. The vFL extends as a longitudinal column between the dFL and VL, and its rostral end connects to the proximal portion of the dFL at the level of most anterior medulla. The VL appears slightly caudal to the rostral end of vFL as a longitudinal column and reaches more caudally than the facial lobe (FL). The dFL includes tubercular and laminated structures. Each tubercle consists of four layers: a marginal layer, a superficial molecular layer, a cell-cluster layer and a deep layer. Sublaminar organization was also found in the cell-cluster layer. No laminar organization was found in either the vFL or VL but distinct clusters of small cells were frequently seen throughout both the lobes. Tracing experiments with the carbocyanine dye diI show that the facial fibers end in the entire dFL and vFL and the anterior portion of the intermediate nucleus of the facial lobe (NIF), while glossopharyngeal fibers terminate in the dorsolateral portion of the anterior VL and the intermediate portion of NIF. Trigeminal fibers project only to the most lateral aspects of the anterior vFL in addition to normal targets such as spinal trigeminal and medial funicular nuclei.  相似文献   

Structural weakening of intramuscular connective tissue during postmortem aging of pork     

Takanori NISHIMURA  Suhong FANG  Toshiaki ITO  Jun‐ichi WAKAMATSU  Koui TAKAHASHI 《Animal Science Journal》2008,79(6):716-721

We studied structural changes in the endomysium and perimysium during postmortem aging of pork using the cell‐maceration/scanning electron microscope method. Immediately post mortem, endomysia sheaths that house individual muscle fibers displayed a honeycomb‐like structure. The sheaths of the endomysium consisted of tightly arranged collagen fibrils in a random network. The perimysium comprised several layers of wavy sheets made up of tightly bundled collagen fibers. While the structure of the intramuscular connective tissues remained almost unchanged up to five days post mortem, the endomysium had resolved into individual collagen fibrils, and the thick sheets of the perimysium had separated into collagen fibers and fibrils at 8 days post mortem. These results provide direct evidence for structural weakening of the endomysium and perimysium during postmortem aging of pork. The shear‐force value of raw pork decreased rapidly within six days post mortem and then decreased slowly until 14 days post mortem. Since the rapid increase in tenderness is mainly due to structural weakening of myofibrils, we conclude that the disintegration of the endomysium and perimysium contributes to tenderization of pork during extended postmortem aging.  相似文献