Cultivar resistance, infection sources, and effective fungicides identified to control Chrysanthemum cutting rot caused by Plectosporium tabacinum     

Mamoru Satou  Katsuhiko Sumitomo  Yoshiaki Chikuo 《Journal of General Plant Pathology》2013,79(3):168-174

Cutting rot in Chrysanthemum is caused by the fungus Plectosporium tabacinum and was found on cuttings of ‘Jimba-No.2’ in 2008. The results of inoculation tests indicated that P. tabacinum infects major Chrysanthemum cultivars in Japan and that cuttings can serve as carriers and propagules of the pathogen already in the soil can serve as inoculum. Other P. tabacinum isolates may also infect Chrysanthemum, and P. tabacinum can be present as an endosymbiont in the plant. In tests of various fungicides, captan, 2,4,5,6-tetrachloroisophthalonitrile, and thiophanate-methyl effectively controlled cutting rot in Chrysanthemum.  相似文献   

Production of Functional Gametes from Cryopreserved Primordial Germ Cells of the Japanese Quail     

Yoshiaki NAKAMURA  Mariko TASAI  Kumiko TAKEDA  Keijiro NIRASAWA  Takahiro TAGAMI 《The Journal of reproduction and development》2013,59(6):580-587

The Japanese quail (Coturnix japonica) is a valuable bird as both an experimental animal, for a wide range of scientific disciplines, and an agricultural animal, for the production of eggs and meat. Cryopreservation of PGCs would be a feasible strategy for the conservation of both male and female fertility cells in Japanese quail. However, the effects of freeze-thaw treatment on viability, migration ability and germline transmission ability of quail PGCs still remain unclear. In the present study, male and female PGCs were isolated from the blood of 2-day-old embryos, which were cooled by slow freezing and then cryopreserved at –196 C for 77–185 days, respectively. The average recovery rate of PGCs after freeze-thawing was 47.0%. The viability of PGCs in the frozen group was significantly lower than that of the control group (P<0.05) (85.5% vs. 95.1%). Both fresh and Frozen-thawed PGCs that were intravascularly transplanted into recipient embryos migrated toward and were incorporated into recipient gonads, although the number of PGCs settled in the gonads was 48.5% lower in the frozen group than in the unfrozen control group (P<0.05). Genetic cross analysis revealed that one female and two male recipients produced live progeny derived from the frozen-thawed PGCs. The frequency of donor-derived offspring was slightly lower than that of unfrozen controls, but the difference was not significant (4.0 vs. 14.0%). These results revealed that freeze-thaw treatment causes a decrease in viability, migration ability and germline transmission ability of PGCs in quail.  相似文献   

Morpho-physiological and molecular mechanisms of phenotypic root plasticity for rice adaptation to water stress conditions     

Nonawin Lucob-Agustin  Tsubasa Kawai  Mana Kano-Nakata  Roel R. Suralta  Jonathan M. Niones  Tomomi Hasegawa  Mayuko Inari-Ikeda  Akira Yamauchi  Yoshiaki Inukai 《Breeding Science》2021,71(1):20

Different types of water stress severely affect crop production, and the plant root system plays a critical role in stress avoidance. In the case of rice, a cereal crop cultivated under the widest range of soil hydrologic conditions, from irrigated anaerobic conditions to rainfed conditions, phenotypic root plasticity is of particular relevance. Recently, important plastic root traits under different water stress conditions, and their physiological and molecular mechanisms have been gradually understood. In this review, we summarize these plastic root traits and their contributions to dry matter production through enhancement of water uptake under different water stress conditions. We also discuss the physiological and molecular mechanisms regulating the phenotypic plasticity of root systems.  相似文献   

Effects of fatty acid-free bovine serum albumin and fetal calf serum supplementing repair cultures on pre- and post-warm viability of biopsied bovine embryos produced in vitro     

Yotsushima K  Sakaguchi M  Shimizu M  Okimura T  Izaike Y 《The Journal of reproduction and development》2004,50(4):471-476

The objective of this study was to investigate the influence of fatty acid-free bovine serum albumin (BSA) or fetal calf serum (FCS) on the re-expansion of biopsied blastocysts and post-warm viability of subsequently vitrified embryos. Firstly, blastocysts produced in vitro were biopsied at Day 7 and cultured to allow repair in TCM199 with 0.3% BSA or 5% FCS for 24 h. The re-expansion rates and mean total numbers of cells of the re-expanded embryos after the repair culture with BSA were almost the same as that with FCS. Secondly, after biopsied embryos were similarly cultured for repair with BSA or FCS, re-expanded embryos were selected for vitrification. After warming and exposure to 0.5 M sucrose with 20% FCS in mPBS, the embryos were cultured in TCM199 with 5% FCS for 24 h. The re-expansion rate and mean total number of cells in re-expanded blastocysts in the BSA treatment group (97.4 +/- 2.9% and 106 +/- 42) was significantly higher than that in the FCS treatment group (51.6 +/- 9.1% and 61 +/- 38), respectively (P<0.05 and P<0.01). In conclusion, both FCS and BSA supplementation can be useful for repairing cultures of bovine biopsied blastocysts; but, compared with BSA supplementation, FCS supplementation during repair culture reduces the post-warm viability of biopsied and subsequently vitrified embryos.  相似文献   

Comparison of factors affecting recruitment variability of walleye pollock Theragra chalcogramma in the Pacific Ocean and the Sea of Japan off northern Japan     

Tetsuichiro Funamoto  Orio Yamamura  Osamu Shida  Kazuhiko Itaya  Ken Mori  Yoshiaki Hiyama  Yasunori Sakurai 《Fisheries Science》2014,80(2):117-126

The Japanese Pacific stock (JPS) and the northern Japan Sea stock (JSS) of walleye pollock Theragra chalcogramma are mainly distributed in the Pacific Ocean and the Sea of Japan off northern Japan, respectively. This paper summarizes and compares the factors affecting the recruitment variability of these two stocks. Spawning season is from December to March for both stocks. JPS recruitment has a positive relationship with the water temperature in January and February, whereas that of JSS has a negative relationship with the water temperature in January, February, and April. One possible reason for this is that pollock larvae have an optimum growth temperature of approximately 5 °C in the field. Drift of early life stages also appears to be an important influence on the recruitment of both stocks. Because the current generated by the northwest wind carries eggs of JPS into the main larval nursery ground, JPS recruitment is enhanced in years when the northwest wind is predominant in February. On the other hand, early life stages of JSS are transported into the nursery ground by the Tsushima Warm Current. However, this current also carries early life stages into the Sea of Okhotsk and offshore, resulting in poor JSS recruitment in years when this current is strong in March. In contrast to JPS, the recruitment of which is significantly impacted by cannibalism, young pollock have not been found in the stomachs of adult JSS. Warm temperatures in the Sea of Japan seem to induce the separation of young and adult pollock, and the shape of the stock–recruitment relationship also suggests that cannibalism is not important for JSS. Based on this knowledge, and on the hatch date distributions of larvae and juveniles, we propose mechanisms that can explain the recruitment fluctuations for JPS and JSS pollock.  相似文献