玉米改良中修改S1轮回选择法

轮回选择是玉米育种程序中的组成部分,而且在其它作物中也日趋重要。Sprague等(1977)、Gardner(1978)、Hallauer等(1978)、Hallauer(1984)对不同的轮回选择方法及应用已有过讨论。用于群体内改良的轮回选择法包括混合选择、S_1、S_5、全同胞群体(FS)、修改FS(MFS)、     

经济价值高、美化环境佳的果树--人心果

人心果 ,属热带常绿乔木。其果实品质优良 ,经济价值高 ,而且常绿 ,周年挂果 ,是商品性栽培的良好果树 ,也是环境的美化果树。1　生物学特性　　叶片浓绿 ,有光泽 ,单叶复生 ,长椭圆形 ,长9 5～ 11 5cm ,宽 2 9～ 3 2cm ,叶柄细长 ,约 2 8～3 1cm ,叶脉呈放射状平行脉 ,叶缘向叶面微卷 ,全缘。花腋生 ,每年 2月开始开花 ,5月果实成熟开始采收。由于人心果周年开花 ,故果实陆续成熟 ,周年都有果实采收 ,而以 6— 8月为最多。果实为浆果 ,略粗糙 ,呈卵形或球形 ,横径 4 5～ 5 5cm ,平均单果重 12 0～ 15 0g ,果实皮黄褐色或淡红褐色 ,果肉…     

Selected pathological, immunohistochemical and ultrastructural changes associated with an infection by Diphyllobothrium dendriticum (Nitzsch, 1824) (Cestoda) plerocercoids in Coregonus lavaretus (L.) (Coregonidae)

The pathological changes induced by an infection of Diphyllobothrium dendriticum (Nitzsch, 1824) plerocercoids in powan, Coregonus lavaretus (L.), from Loch Lomond, Scotland, were assessed using immunohistochemical and ultrastructural techniques. In a sample of 26 powan, the occurrence of encysted plerocercoids of D. dendriticum on the outer surface of the stomach was 38.5% (n = 10) with the number of cysts ranging from 4 to 15 and measuring 4.2 +/- 1.0 mm x 3.4 +/- 0.9 mm (mean +/- SD). Histological examination of intestinal samples also revealed plerocercoids (2-21) encapsulated within a proliferation of mesenteric fibrous tissues of the gastric wall and, occasionally, by the gut lamina propria-submucosa and lamina muscularis. In section, cysts were tri-layered and were formed from a series of concentric whorls of fibroblast and collagen fibre-based connective elements. The extent of necrosis within each muscle layer and the serosa of the stomach differed, notably within the latter that was marked by a chronic inflammatory reaction and fibrosis. Within the cyst and around it, a large number of degranulating mast cell/eosinophilic granule cells were seen, in addition to melano-macrophage centres. Immunohistochemical staining of sections of infected stomach revealed a high density of elements, in close proximity to plerocercoids, staining positive for serotonin, bombesin, substance P and galanin. Uninfected material did not present the same levels of activity. Sections through both infected and uninfected tissue were also tested for elements containing vasoactive intestinal peptide, met-enkephalin, calcitonin gene-related peptide, neuropeptide Y and nitric oxide synthase, but these were absent.     

五指山地区水和沉积物中HCHs、DDTs和PCBs分布特征及生态风险

使用GC/ECD分别对海南五指山地区11个采样点水中和表层沉积物中的六六六(HCHs)、滴滴涕(DDTs)和多氯联苯(PCBs)进行了分析测定,获得了3种持久性有机氯污染物其在该地区的含量与分布特征。有机氯农药组分分布特征研究表明,五指山地区水环境中HCHs和DDTs主要来自于早期残留和历史积累,尽管个别采样点DDTs仍有新的污染源输入,而该地区水环境中的PCBs可能是由大气长距离输送而来的。与世界其他地区相比较,五指山地区水体中的持久性有机氯污染物的含量还处于一个较低的水平,生态风险不大。     

长白山浅山区1985、1986年椴树泌蜜产量的气候分析

椴树是我国主要蜜源之一,大面积分布在东北,泌蜜量丰富蜜质好,然而年产量极不稳定,给蜂农放蜂造成难以计划的困难。为了逐步攻克这一难题,我们对吉林省敦化地区椴树开花泌蜜与气候条件之关系进行了观测试验,计算分析,得出该地区1985、1986年椴蜜低产歉收主要因不同类型的气候异常所致。这一工作为椴树泌蜜产量的预报研究     

孚优选蕉柑砧木比较研究

用归湖酸桔、红柠檬、福桔、化桔、江西红桔和枳等6个砧木品种嫁接孚优选蕉柑,对不同砧穗组合孚优选蕉柑的亲和力、树体生长特性、早结丰产性、产量和果实品质等进行比较分析.试验结果表明,枳不宜作孚优选蕉柑砧木,红柠檬效果不好,归湖酸桔、福桔、化桔、江西红桔适宜作孚优选蕉柑砧木,特别是江西红桔砧综合性状最好,适宜在丘陵山地密植,值得推广应用.     

Anti-stress effects of Glycine tomentella Hayata in tilapia: inhibiting COX-2 expression and enhancing EPA synthesis in erythrocyte membrane and fish growth

The objective of this study was to elucidate the in vivo effects of the ethanol extract of wooly Glycine tomentella Hayata (GTE) root on tilapia to elucidate whether GTE has antistress activity. Tilapia as an animal model were fed with or without GTE, then injected with lipopolysaccharide (LPS) or ammonium chloride (NH(4)Cl). The tilapia were exposed to 100 mg/L of aqueous NH(4)Cl, and/or acute cold stress. Growth parameters of the tilapia were measured during the feeding trials. Tilapia injected with GTE (20 μg/g of fish), NH(4)Cl (100 μg/g of fish) and/or LPS (1 μg/g of fish) were then sampled 2 h poststimulation. GTE significantly inhibited cyclooxygenase-2 expression and hemoglobin (Hb) dimer formation (36 kDa). GTE also improved growth and blood viscosity and upregulated eicosapentaenoic acid content of erythrocytes. The in vivo results indicated that GTE (20 μg/g of fish) can be applied as a stress-tolerance enhancing agent for the aquaculture industry.     

Chemical composition of caneberry (Rubus spp.) seeds and oils and their antioxidant potential

Caneberries (Rubus spp. L.) are grown primarily throughout the Pacific Northwestern United States and Canada. Processing of caneberry fruit typically removes the seed, and the development of a value-added use of seeds could expand the market for caneberries and the profit margins for growers. An initial step toward the use of the seeds is a characterization of seed and oil. Our investigation has described compositional characteristics for seeds of five commonly grown caneberry species: red raspberry, black raspberry, boysenberry, Marion blackberry, and evergreen blackberry. Seeds from all five species had 6-7% protein and 11-18% oil. The oils contained 53-63% linoleic acid, 15-31% linolenic acid, and 3-8% saturated fatty acids. The two smaller seeded raspberry species had higher percentages of oil, the lowest amounts of saturated fatty acid, and the highest amounts of linolenic acid. Antioxidant capacities were detected both for whole seeds and for cold-pressed oils but did not correlate to total phenolics or tocopherols. Ellagitannins and free ellagic acid were the main phenolics detected in all five caneberry species and were approximately 3-fold more abundant in the blackberries and the boysenberry than in the raspberries.