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961.
从5000余只杂种兔中,按公母比例1∶8选择300余只体重大、产毛量高的个体进行横交固定,经过4个世代的选育,兔只(11月龄)平均体重达5386克,年产毛量1424克,粗毛率11.74%,结块率2.24%,胎产活仔7.26只,料毛比43∶1。种兔外貌特征一致,遗传性能稳定。现有核心群种兔1200只,繁殖群7200只,生产群2.5万余只,向省内外推广繁育28万只,各项生产指标均达到或超过预定标准及全国家兔育种委员会制定的“德系长毛兔种兔鉴定标准”和“粗毛型长毛兔的选育指标”。 相似文献
962.
海南木本饲用植物资源考察及营养价值评价 总被引:2,自引:0,他引:2
根据海南及部分周边岛屿的考察,报道了海南木本饲用植物的种质资源及其分布和营养价值。讨论了海南木本饲用植物的开发利用前景。 相似文献
963.
本文建立了检测鸡新城疫病毒的Dot-ELISA法。用该法检测自然发病鸡群的粪便样品和脾组织匀浆各82份,鸡新城疫病毒的检出率(51.2%,74.4%)高于血球凝集试验(36.6%,61.0%),且两种方法具有良好的平行关系。该法操作简单,结果明显,直观,适用于基层检测鸡新城疫病毒。 相似文献
964.
965.
C T Liu R D DeLauter M J Griffin R T Faulkner 《American journal of veterinary research》1978,39(2):279-286
Selected cardiovascular and renal functions were measured for 5 hours in conscious, chair-restrained, female rhesus macaques (Macaca mulatta) after IV (0.05 and 1.0 mg/kg) or oral (1.0 mg/kg) administration of staphylococcal enterotoxin B (SEB). Cardiovascular functions, renal hemodynamics, and renal metabolism were also studied between 6 and 11 hours after IV SEB inoculation. Oral SEB produced few changes in cardiorenal functions. In contrast, IV SEB produced hypotension, tachycardia, increased total peripheral and renal vascular resistance, and decreased cardiac and renal functions. The early significant (P less than 0.05) renal depression was not associated with hypotension (mean arterial blood pressure greater than 100 mm of Hg). However, all measured renal functions except extraction ratio of PAH were positively correlated with decreased blood pressure (r = 0.52 - 0.71) in the later phase of SEB toxemia. It is concluded that the kidney is one of the organs affected by IV SEB. Renal impairment may partially contribute to death during SEB enterotoxemia in macaques. 相似文献
966.
967.
Rentao Liu Halin Zhao Xueyong Zhao Xiaoan Zuo Sam Drake 《European Journal of Soil Biology》2009,45(5-6):417-422
The response of macrofauna to dune conversion from mobile dunes to fixed dunes was investigated in Horqin sandy land, northern China. Macrofaunal communities were compared in four major stages: mobile dunes (MD), semi-mobile dunes (SMD), semi-fixed dunes (SFD) and fixed dunes (FD). Macrofauna were collected by hand in the field and identified in the lab on the basis of features observed under a magnifying glass. They were then classified into morphotypes at the order and family level. Environmental parameters indicated a significant alteration of the soil environment in the conversion process. A clear increasing trend in abundance, richness, and diversity of the macrofaunal community could be established from mobile dunes to fixed dunes. Data for the different taxa suggested specific responses to dune conversion. Specific groups in the initial stage were predators (Labiduridae and Myrmeleontidae larvae, presumably feeding on Noctuidae and other small flying insects), which in the intermediate stages were replaced by saprophagous taxa (Diptera larvae, feeding on many decaying roots buried in semi-mobile and semi-fixed dunes), and burrowing Tenebrionidae (adults, then larvae) with herbivorous Hemiptera in later fixation stages with higher plant density and cover. Overall, the conversion process, particularly the fixed dunes, provided more suitable habitats with greater soil organic matter and plant cover supporting macrofaunal communities with higher diversity, which further enhanced the stabilization process, benefiting the restoration of soil and vegetation in this semiarid sandy area. 相似文献
968.
芥菜型油菜与甘蓝型油菜种间杂种二代分离观察 总被引:5,自引:1,他引:5
从芥菜型油菜×甘蓝型油菜种间杂种F1自由授粉获得的F2的叶型、现蕾期、始花期、雄蕊发育、花粉活性和种子育性的分离观察结果表明,芥甘杂种F2超亲分离,产生大量变异类型,可根据花粉可染率和角果长度对F2植株种子育性进行间接选择。 相似文献
969.
黄瓜对低温和弱光的耐受性是两个相对独立的性状,需要单独进行评价.设计了以叶面积增长量为主要性状指标的弱光(或弱光 偏低温)耐受性的评价指标体系和以冷害指数作为临界低温耐受性评价指标的快速筛选体系,两者可复合实施. 相似文献
970.
The influence of fruit load on the leaf characteristics and on the distribution of dry matter (DM) and nitrogen (N) in sweet pepper (Capsicum annuum L., cv. Cornado) plants was investigated under Mediterranean glasshouse conditions during a winter–spring production cycle (from December till June). DM weight of all organs (roots, stems + petioles, leaves and fruits) and N content were determined throughout the growing cycle over a 3-week interval. The results showed that the cyclic fruit load pattern (production flushes) was associated with strong variations of N-leaf content on an area basis and specific leaf weight, SLW. On a whole plant scale, the value of SLW dramatically decreased (≈30%) with increasing fruit load; the reverse held true as long as the fruit dry weight remained low (<30 g pl−1). The decline in SLW was coincident with a shift in distribution of DM and N in the plant, both preferentially diverted to the fruits. The time evolution of DM and N fractions in organs exhibited periodic fluctuations, with a duration close to the length of a fruit growth cycle (about 70 days, from anthesis to harvest). Linear relationships were found between the fraction of dry mass and N in fruits, and those of the other organs. The slope of these relationships was considered as an indicator of the response and sensitivity of the organ growth to an increase in fruit load. The root dry mass fraction was the most affected by increases in fruit load (slope of −0.75), while the N fraction in roots and in leaves was affected to a similar extent (slope of −0.50 and of −0.40, respectively). We conclude that, in the sweet pepper, the cyclic pattern of fruit load induces opposite cyclic patterns of dry matter and N content in the other aerial organs as well as in the roots, thereby reflecting close shoot–root coordination in the allocation of carbon and nitrogen resources among the organs. Finally, we discuss the possible implications that could derive from these findings for modelling dry matter partitioning in plants subjected to continuous fruit harvesting. 相似文献