五味子不同外植体愈伤组织的诱导

以五味子的嫩茎段、叶片、叶柄、果柄为外植体,以MS附加相同激素配比的培养基为基质,进行了诱导北五味子愈伤组织的适宜外植体及培养条件的筛选。结果表明：北五味子嫩茎段在MS＋6-BA1．0mg／L＋NAA0．2mg／L＋2,4-D0．1mg／L＋IBA0．3mg／L诱导效果较好,在附加MS＋6-BA2．0mg／L＋ZT0．1mg／L的诱导芽效果较好。     

壳聚糖在茶树上的应用效应

采用叶面喷施的方法，对壳聚糖在茶树上的应用效应进行了研究。结果表明，壳聚糖能促进茶树芽叶萌发和生长，提高茶叶产量，增加茶叶中水浸出物和氨基酸含量，降低酚氨比。壳聚糖对茶叶中茶多酚含量有一定的影响，而对咖啡碱影响不大。本试验所设置浓度范围内，150mg／kg是叶面喷施壳聚糖较适宜的浓度。     

几个籼稻品种的成熟胚愈伤组织植株再生体系的建立

组织培养技术在作物改良上的成功应用需要合适的植株再生体系。本试验以7个籼稻成熟胚为材料，通过优化激素配比，建立适合于水稻遗传转化的高频植株再生体系。研究结果表明，NB 2mg／L2，4-D适合于供试品种的成熟胚愈伤组织的诱导，诱导率达90％以上；在分化培养基中添加3．0-3．5mg／L KT，0．5～1．0mg／L NAA和5．0mg／L ABA的激素配比，明恢81、N175、航1号的最高分化率分别达72．7％、80．0％和78．0％；移栽成活95％以上。     

玉米DNA的小量快速提取

以玉米的幼叶为实验材料,用小量快速法提取玉米总DNA.提取的DNA经0.8%琼脂糖凝胶电泳检测,结果发现DNA质量较好,所得的DNA可用于RAPD和DNA酶切等技术.此法具有提取速度快、DNA质量好和经济实用等优点,为玉米及其他植物DNA的提取提供了一个快速、简便的途径。     

甜菜重要农艺性状的数量性状基因座(QTL)研究进展

阐述了农作物数量性状基因座(QTL)在遗传育种中的地位和意义,介绍了作物QTL的基本原理和方法及在甜菜上的研究进展。     

花生种子发芽率快速测定法

用TTC氯化三苯四氮唑)染色法和红墨水染色法对35份花生品种进行种子生活力的测定,并与其发芽率比较,研究结果表明,TTC法和红墨水法测定的种子生活力和发芽率之间存在极显著的正相关关系。TTC染色法和红墨水法都可用于花生种子发芽率的快速测定,其中TTC染色法的测定结果可靠性高于红墨水染色法。     

湖北稻茬小麦主茎、分蘖1、分蘖2和分蘖3的成穗率、产量贡献率及主要农艺性状分析

合理的茎蘖组合是提升小麦绿色高效生产的重要因素。为了解湖北稻茬小麦主要茎蘖对产量及主要农艺性状的影响,以大穗型小麦品种川麦104和多穗型小麦品种扬麦15为材料,于2016-2018年在湖北十堰和武汉两地稻茬麦大田条件下,设置低(1.35×106~1.65×106株·hm^-2)、中(2.85×106~3.15×106株·hm^-2)、高(4.35×106~4.65×106株·hm^-2)三种种植密度,分析了主茎(S)、分蘖1(T1)、分蘖2(T2)和分蘖3(T3)(按出现先后顺序)的成穗率、产量贡献率及相关农艺性状的表现。结果表明:(1)湖北稻茬小麦成穗茎蘖农艺性状表现值偏低,除穗长和茎高受品种的影响最大外,其他被测性状受影响程度表现为蘖位>种植密度>品种;(2)在主茎均能成穗的情况下,分蘖成穗率随蘖位和种植密度的升高而降低,大穗型品种川麦104的降幅大于多穗型品种扬麦15;(3)主茎产量贡献率随种植密度的升高而升高(35.12%~54.50%),分蘖1产量贡献率稳定在23.25%~25.50%,分蘖2和分蘖3的产量贡献率随种植密度升高而降低,分别为14.59%~23.22%和5.42%~16.77%;(4)主茎的穗粒数(35.94~44.13粒)和穗粒重(1.44~1.93 g)显著高于其分蘖,茎高、茎蘖收获指数和穗茎节长只在川麦104中、高种植密度下的分蘖3与其他茎蘖差异显著;穗长、可孕小穗数和不孕小穗数有随蘖位和种植密度升高而变劣的趋势。聚类分析得出:湖北稻茬小麦绿色高效生产模式,以主茎成穗为主体,低种植密度下增加分蘖1和分蘖2,争取分蘖3成穗为辅;中种植密度下争取分蘖1+分蘖2成穗为辅;而高种植密度下争取分蘖1成穗为辅。     

奥利亚罗非鱼（♀）、鳜（♂）及其子代间遗传关系的研究

罗非鱼生长快、味道好,是人们喜爱的鱼类,现已是世界性养殖鱼类,但它不能忍受低温,因此影响其养殖业的进一步发展。鳜则是名贵性鱼类,但其终生摄食活的鱼虾,这也限制了其养殖的发展。奥利亚罗非鱼(Oreochromisaurea)属鲈形目、鲡鱼科,鳜(Sinipercachuatsi)属鲈形目、脂科,它们间的杂交为科间杂交。鱼类科间杂交成功率很低,种间杂交有时可获得具有双亲性状的杂种鱼,有时也可发生雌核发育[1]。本研究中奥利亚罗非鱼雌鱼性染色体为ZW,其卵子如能在鳜精子刺激下行雌核发育,则可在短时间获得奥利亚罗非鱼纯系。在本文中,利用RAPD标记,对…     

Perkinsus sp. infestation in carpet-shell clams, Ruditapes decussatus (L), along the Portuguese coast. Results from a 2-year survey

This study characterises Perkinsus atlanticus disease prevalence and intensity within the economically important beds of the clam Ruditapes decussatus along the Iberian Atlantic coast. Samples were collected from five different sites along the Portuguese coast (Ria Formosa, Ria do Alvor, V.N. Milfontes, Aveiro, Lagoa de Obidos) and in Galicia (Ria de Arosa) between winter 2000/2001 and 2002/2003. The infection level was evaluated by the Ray Fluid Thioglycollate medium (RFTM) method using the body burden assay. In addition, the measure of the condition index (CI) (percentage between the edible part and the total weight of the clams) was conducted to investigate a possible correlation between this parameter and the intensity of the infection. However, no clear relationship between infection intensity and condition index (CI) could be determined although a significant decline in CI was found for heavily infected clams. Results of a 2-year survey demonstrate the presence of Perkinsus sp. in all sampling sites albeit with different intensities. Sites where human interference was minimal showed the lowest levels of infection. There were no significant differences in Perkinsus sp. infection intensity between samples collected in winter and summer, in contrast with several studies describing higher intensities at the end of the summer. Nevertheless, major differences were observed from year to year and site to site, indicating that factors other than those responsible for seasonal climatic variations might affect the prevalence and the intensity of Perkinsus sp. infection.     

Comparison of susceptibility of various fish species to experimental infection with channel catfish virus

Channel catfish virus (CCV) disease is an acute haemorrhagic disease in juvenile channel catfish ( Ictalurus punctatus ). To date channel catfish is the only species affected by natural outbreaks of the CCV but juvenile large mouth bass ( Micropterus salmoides ) and silurus ( Silurus meriaionalis ) have suffered high mortalities in recent years in China. Histopathological phenomenon of sick fish is similar to CCV disease, and the identified virus was CCV. In this report, the pathogenicity of infectious CCV was examined by infection trials on the first known host species, the channel catfish and other teleosts. Our results indicated that there were higher detection rates of CCV from large mouth bass and silurus fish. Channel catfish virus did not induce mortality in other cypriniformes, but histopathological studies revealed that carp might be infected by both bathing and intraperitoneal infection. No deaths, clinical or histopathological signs, were found in the six other species exposed by immersion or injection. Experimental infection studies confirm that CCV infect not only channel catfish but also other species (large mouth bass, silutus and carp). The outbreaks of CCV disease only occurred when the cultured temperature was above 25 °C.