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Sergei Gorshkov Galina Gorshkova Barbara Colorni Hillel Gordin 《Journal of the World Aquaculture Society》2004,35(2):167-177
To produce a monosex female population of European sea bass Dicentrarchus labrax, fry were fed dry diets containing dosages of 12.5, 25, and 50 mg/kg food of either the natural estrogen estradiol-170β(E2) or the synthetic estrogen 17α-ethynylestradiol (EE2) for 60 d starting at 88 d post-hatch (dph). A complete feminization (100%) was achieved in all E2-treated groups at the age of 11 mo (330 dph). All affected fish had ovaries similar in size and histological structure to those of control females. In the E2-treated groups, feminized fish were heavier and longer than untreated controls (males and females combined). In control groups females exhibited significantly higher body weight and total length than males. Untreated females from control groups and females from the group treated with E2 at 12.5 mg/kg food had similar body weight, suggesting that in sea bass growth is related to phenotypic sex. In the Entreated groups, survival rates were similar to those of the control fish. A relatively high percentage of females was obtained in the EE2-treated groups (from 38.6 to 96.5%). However, the gonadal development in these fish was significantly suppressed and a dose-dependent reduction of gonadal sizes was evident. Treatments with the EE2 (12-5, 25, and 50 mg/kg food) resulted in many fish having abnormal (2.9-5.4-39.8%, respectively) and sterile (0.6-6.0-21.6%, respectively) gonads. Effects also included significantly lower weight and shorter length when compared with controls. Furthermore, fish fed with EE2 at the dosage of 50 mg/kg food had high mortality rate. A simple protocol was developed for the complete feminization in sea bass in which the fry (80-100 dph) were fed to satiation two times daily with a diet containing 12.5 me of E2/ks food for a period of 60 d. 相似文献
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Amplified Fragment Length Polymorphism (AFLP) information was used for identification of mango (Mangifera indica L.) cultivars, for studying the genetic relationship among 16 mango cultivars and seven mango rootstocks and for the construction
of a genetic linkage map. Six AFLP primer combinations produced 204 clear bands and on the average 34 bands for each combination.
The average Band-Sharing between cultivars and rootstocks was 83% and 80%, respectively. The average Band-Sharing for mango
is 81%. The probability of obtaining a similar pattern for two different mango cultivars and rootstocks is 6 × 10−3and 2 × 10−3, respectively. A preliminary genetic linkage map of the mango genome was constructed, based on the progeny of a cross between
‘Keitt’ and ‘Tommy-Atkins’. This linkage map consists of 13 linkage groups and covers 161.5 cm defined by 34 AFLP markers.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Daniel Hillel 《植物养料与土壤学杂志》2009,172(1):5-9
The soil is a vital, complex, and labile medium. To manage it effectively and sustainably, we must strive to understand its attributes, functions, and environmental interactions. Toward this holistic end, we need to overcome traditional disciplinary and institutional barriers so as to promote interdisciplinary cooperation among teams of scientists with different but mutually complementary specialties. Herein, we provide an historical and cultural review of the evolving relationship between humanity and the soil. 相似文献
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分子标记在鸡生物多样性评估中的应用 总被引：1，自引：0，他引：1
品种、群体、家系和个体基因组的DNA变异代表了特定品种内的遗传多样性.对遗传多样性机制研究的深入有助于改变动物的驯化模式,有助于评估群体之间的遗传关系和群体内的遗传变异.另外,该工作也可以确定应用于育种的重要DNA序列.…… 相似文献
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Summary Various DNA fingerprint probes were applied to Carica papaya and other Carica species for both identification and genetic analysis.Each of the Carica papaya cultivars is characterized by a specific DNA fingerprints pattern. Various Carica species also have specific patterns which distinguish them from one another. Band sharing levels were used to estimate the relatedness between the various Carica species.Genetic analysis of 11 progeny from a cross between the Carica papaya cultivars 17/82 and 112 suggests that application of DNA fingerprinting to Carica papaya breeding, could make the process more efficient. Genetic analysis of the DNA fingerprint bands revealed no linkage or allelic relationship among the bands analyzed, indicating that these loci are not clustered in the Carica genome. 相似文献
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通过对“小麦-玉米-甘薯”旱三熟连续3年9茬作物（玉米、甘薯、小麦）施用氯化钾试验结果的灰色关联分析表明：增施钾肥和有机肥能提高“麦-玉-薯”旱三熟生产系统的稳定性；作物经济产量随施钾量提高而提高，增施有机肥也可显著提高作物产量，特别是玉米、甘薯的生物产量；在保证无机氮、无机磷供应的前提下，中钾处理增产效果高于低钾加有机肥处理，而低钾处理增产效果又高于有机肥；有机肥及钾肥能显著提高玉米、小麦的粗蛋白含量、穗粒数、千粒重，促进甘薯薯块增大增重。土壤速效钾含量随着施钾量增加而增加。 相似文献
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Summary Associations between DNA fingerprint fragments and 16 avocado quantitative trait loci were tested for in two avocado tamilies by one way analysis of variance and multiple regression analysis. Based on these two analyses the fragments P4, P8, E2 and E5 in Pinkerton × Ettinger progeny were found to be associated with harvest duration, skin color, skin thickness and skin surface, respectively. The fragments P1, P8, B1 and B4 in the Pinkerton × Bacon progeny (half sibs of the original population) were found to be associated with fruit weight, skin color, seed size and peeling, respectively. Based on the original Pinkerton progeny as well as on the half sibs progeny, the fragment P8 was found to be associated with black-purple fruit skin color.The fragment pattern intensity of DNA pools of progeny having either green or black-purple fruit skin color —supported these data. These results are interpreted as genetic-linkage between the DNA fingerprint fragment P8 and locas (1) regulating fruit skin color in avocado. 相似文献
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This research is aimed at quantitative genetic analysis of several avocado traits and cultivars. The experimental material consists of our avocado breeding project in which data were collected from several crosses as well as selfings of cultivars. Parenthood was determined by isozymes and the seedling progenies were assessed for eight traits. A biometrical genetic approach for analysis of this breeding project is presented. Genetic profiles of the traits and cultivars were detailed by several characteristics: level of heterozygosity and dominance deviation, dominance of alleles, dominance direction, general evaluation of additive and non-additive genetic variance, maternal inheritance, and allelic differences among the various cultivars in major genes controlling the same quantitative trait. Five avocado cultivars: ‘Fuerte’, ‘Hass’, ‘Ettinger’, ‘Tova’, and ‘Rosh-Hanikra’, were characterized separately for each trait. Practical conclusions for the breeder regarding economically important quantitative traits are discussed. 相似文献