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41.
Cryopreservation of shoot tips of Chrysanthemum morifolium and related species native to Japan 总被引：1，自引：0，他引：1
Summary The shoot tips of Chrysanthemum morifolium (syn. Dendranthema grandiflorum) and related species native to Japan were cryopreserved using preculture for 2 days, slow cooling (0.2°C/min) until –40°C with 10% dimethyl sulphoxide and 3% glucose prior to immersion into LN2 and rapid thawing. High survival rates were observed in 3 cultivars of chrysanthemum, 12 species and 2 interspecific hybrids, and slightly low survival rates in 3 species. The shoot regeneration rates of the frozen shoot tips varied from 9.4 to 100% depending on species. Shoot tips of chrysanthemum showed high viability even after a storage of 8 months in LN2. The thawed chrysanthemum shoot tips grew and flowered normally in a greenhouse under natural conditions.Abbreviations BA
6-benzylaminopurine
- DMSO
dimethyl sulphoxide
- NAA
1-naphtalenacetic acid 相似文献
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Kusuda S Nagami H Kusunoki H Nishikaku T Nakagawa D Takida T Kurita D Uemichi K Fukai M Kubota H Ueda K Ooe T Okuda K Ueda K Doi O 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(10):1093-1095
The serum and fecal testosterone (T) concentrations and testicular sizes of two male bharals (Pseudois nayaur) were determined for approximately one year. The profiles of the fecal T concentrations showed a similar tendency as the profiles of serum T concentrations, and there was a significant correlation between serum and fecal T concentrations (r=0.72). T concentrations rose drastically in October and decreased gradually until January. The maximum testicular size was observed between November and January. Semen collected between December and January was excellent in quality and comparable to domestic sheep and goats. The active periods of the testes were synchronized with the early breeding season of females. 相似文献
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A water balance model for characterization of length of growing period and water stress development for rainfed lowland rice 总被引：1，自引：0，他引：1
There is large year-to-year variation in rice production across the Mekong region (Laos, Cambodia and Thailand) due to uncertainty in the timing of the onset of the wet season and drought stress that may develop at any time during the growth of rainfed lowland rice. Unique to the nature of lowland water balance is a large component of deep percolation water loss, which depends on soil texture. The objectives of this study were to develop a soil water balance model for calculating the amount of water held in field storage (i.e. in soil and, if there is standing water, above the soil surface) and to apply it to determine the length of growing period (LGP) and water stress development in relation to soil type and rainfall pattern for the rice ecosystem. The water balance is computed separately for above-ground plus topsoil layer and subsoil layer. Components of the water balance are the existing amount of stored water, rainfall, evapotranspiration, deep percolation, and runoff. The deep percolation rate was determined from clay content in each soil layer. The model runs with daily or weekly weather data to estimate the soil water level for the growing period in the wet season. The model was validated with data collected from top, middle and bottom of rainfed lowland fields in Savannakhet province, Laos. The best correlation between the observed and simulated water level was obtained (r2 = 0.41) for middle fields. The simulation results showed that LGP varied greatly from year to year, particularly in locations with sandy soils, due mostly to variation in monthly rainfall occurring at the early part of the growing season (April), but also to some extent by variation at the end of growing season (October). Soil texture on the other hand is shown to have a large influence on the end of the rice growing period and hence LGP, and also water stress development during growth. Sandy soils with clay content less than 7% that are prevalent in the province are shown to cause frequent water stress and early finish in rainfed lowland rice. The model accordingly provides reasonable outputs that can provide a geographical dimension of soil hydrological patterns for various rice growing environments, and also identify the spatial pattern of drought stress that is likely to occur. Model outputs can be used to provide guidelines for practical advice to the rice farmers and researchers for determination of appropriate crop management strategies (e.g. time of planting, varieties), and policy makers for investment decisions on inputs (e.g. fertilizer price) aimed at increasing rice productivity in this Mekong region. 相似文献
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Iizuka A Haritani M Shiono M Sato M Fukuda O Hagiwara A Miyazaki S Tanimura N Kimura K Nakazawa K Kobayashi M Takahashi T Saito T Fukai K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(7):693-699
Seven of 92 lactating Holstein cows on a dairy farm developed urticaria with alopecia and decreased milk production, and three of the seven died over the course of 7 to 18 days. Pathologic examination of the three cows, including the two dead and one euthanized cow, revealed that the skin, liver, spleen, kidneys, heart, salivary glands, pancreas, adrenal glands, mammary glands, lymph nodes, and trigeminal ganglia had lymphocytic to lymphogranulomatous inflammation. Inflammation predominated by lymphocytic infiltration was prominent in the heart, pancreas, mammary glands, adrenal gland, and trigeminal ganglia. Severe granulomatous inflammation with multinucleated giant cells was present in the spleen and kidneys. These lesions and their distributions were most similar to those seen in suspected cases of citrus pulp toxicosis and hairy vetch toxicosis. The outbreak of this disease resolved with the elimination of Citrus pulp from the feed. Immunohistochemical detection of lymphocytes and macrophage markers confirmed dramatic hyperplasia of CD3-positive T lymphocytes in these lesions. This strongly suggested that a type 4 hypersensitivity reaction played a role in the development of the lesions. 相似文献
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Sipaseuth J. Basnayake S. Fukai T.C. Farrell M. Senthonghae Sengkeo S. Phamixay B. Linquist M. Chanphengsay 《Field Crops Research》2007
Rice is a major source of food for more than 2.7 billion people and planted on nearly 130 million hectares in which 10% is subjected to low temperature problems. Dry season (DS) rice cropping has been expanding in the high altitude lands in Asia and the low temperature is one of constraints to rice production. This study aims to quantify the potential for growing irrigated rice in DS, particularly in high altitude areas in northern Lao PDR where temperatures are low and pose problems for seedling establishment. Research focused on identifying sowing times to avoid the detrimental effects of low temperature, the optimal seedling age for transplanting, the potential of plastic covers and half burnt paddy husk layer to protect nursery seedbeds from low temperature and varieties suitable for this environment. Studies were conducted over 5 years and were examined at six locations. In two locations, where temperature was favorable for rice production throughout the DS, time of sowing was not critical. In higher altitude areas in northern Lao PDR, however, low temperature caused establishment problems in nurseries. In these areas, mid-November sowing before the onset of winter reduced the low temperature effects on seedling establishment while sowing in mid winter (December and January) increased the risk of failure. There were no significant effects of seedling age (25-, 35- and 45-day old) for transplanting on yield for DS rice. Using clear plastic to cover the nursery increased minimum temperatures on average by about 4 °C, which improved seedling growth and resulted in higher grain yield. The mean minimum temperature of 12 °C for 30 days after seeding is critical and temperature below 12 °C resulted in high risk of crop failure due to poor germination, poor seedling growth or insufficient seedlings. Rice needs to be sown at times where the mean minimum temperature exceeds 12 °C or plastic covers are required to protect seedlings. The current popular varieties did not show significant tolerance to extreme cold temperature. 相似文献
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M. Ouk J. Basnayake M. Tsubo S. Fukai K.S. Fischer S. Kang S. Men V. Thun M. Cooper 《Field Crops Research》2007
While a large genotype-by-environment (G × E) interaction component of variance for grain yield (GY) has been widely reported for rainfed lowland rice, the reasons for such large interactions are not well known. A random reference population of 34 genotypes taken from the Cambodian rice improvement program was used to examine the magnitude and nature of G × E interactions for GY in Cambodia. These genotypes were evaluated in a multi-environment trial (MET) conducted across 3 years (2000–2002) and eight locations in the rainfed lowlands. The G × E interaction was partitioned into components attributed to genotype-by-location (G × L), genotype-by-year (G × Y) and genotype-by-location-by-year (G × L × Y) interactions. The G × L × Y interaction was the largest component of variance for GY. The G × L interaction was also significant and comparable in size to the genotypic component (G). The significant G component was partly explained by a group of four genotypes that were broadly adapted to different environmental conditions represented by three environmental groups. The three environmental groups were identified from a pattern analysis, and the grouping was partly related to the time of sowing, and hence water availability at flowering. A major factor contributing to the large G × L × Y interactions for GY was late maturing genotypes being affected greatly when soil water availability at flowering was reduced greatly, compared to earlier maturing genotype groups. While the differential genotypic responses to the water availability environment explained part of a large G × E interaction for GY, other non-water related environmental conditions also appeared to have contributed to the interaction. Three target environments were identified for focusing efforts of the breeding programs in Cambodia, and four putative genotypes were selected for their high yield and wide adaptation in the rainfed lowlands. 相似文献