Variation in the loss of seed dormancy during after-ripening of wild and cultivated rice species

BACKGROUND AND AIMS: The aim of this paper was to verify the variation in the loss of seed dormancy during after-ripening and the interspecific and interpopulation variability in the degree of dormancy of seven wild and two cultivated rice species comprising 21 populations and two cultivars. METHODS: Four wild rice species from South America, Oryza glumaepatula, O. latifolia, O. grandiglumis and O. alta, and two O. sativa cultivars were tested in one experiment. In a second experiment, five wild species, O. punctata, O. eichingeri, O.rufipogon, O. latifolia and O. glumaepatula, and one cultivated species (O. glaberrima) were evaluated. Initial germination tests were performed soon after the seeds were harvested and subsequently at 2-month intervals, for a total of six storage periods in the first experiment and three in the second. All tests were conducted in the dark at a temperature of 27 degrees C. KEY RESULTS: Different patterns of after-ripening among populations within and between species were observed. CONCLUSIONS: The cultivated species (O. sativa and O. glaberrima) and, amongst the wild species, the tetraploids O. latifolia, O. grandiglumis and the diploids O. eichingeri and O. punctata, had weak dormancy, losing it completely 2 months after harvest, while O. rufipogon and O. glumaepatula exhibited pronounced dormancy. The latter showed different patterns of after-ripening between populations indigenous to the Amazon region and those originating in the Paraguay River system. Seeds of Solimoes (Amazon) and Japura origin showed weak dormancy whereas those of Paraguay origin showed deep dormancy. Ecological differences among natural habitats may be involved in such differentiation.     

棘豆属分类学新资料

作者同意赵一之先生关于海拉尔棘豆Ｏ。ｈａｉｌａｒｅｎｓｉｓ Ｋｉｔａｇ。这是尖叶棘豆Ｏ。ｏｘｐｈｙｌｌａ ＤＣ的观点,但提出其变种光果尖叶棘豆的变种名应是Ｏ。ｏｘｙｐｈｙｌｌａ ＤＣ。ｖａｒ。ｐｓｉｌｏｃａｒｐａ Ｇ．Ｚ．Ｑｉａｎ。     

五种线虫生殖锥的形态研究

在光镜和扫描电镜玻地似血矛线虫,捻转血予线虫,辐射食道口线虫,粗纹食道口线虫,哥伦比亚食道一虫的生殖进行观察比较。结果表明：似血矛线虫的生殖锥的生殖附器只有一对乳突,而捻转血矛线虫的生殖附器有２对乳突。     

华南紫萁和粗齿紫萁的配子体发育研究

以腐叶土为基质 ,对华南紫萁和粗齿紫萁进行了孢子繁殖 ;利用Olympus显微镜观察和记录了它们的孢子萌发和配子体发育过程。结果表明 ,两者的孢子及配子体性状极为相似 :孢子同型 ,三裂缝 ,壁厚 ,含叶绿体 ,萌发快 ;在常温下 ,孢子的存活期短 ;孢子萌发需要光 ,萌发类型为紫萁型 ;丝状体阶段不发达 ,仅 2～ 3个细胞 ;原叶体无毛状体 ,中脉厚 ,精子器和颈卵器较大 ;由原叶体发育成幼孢子体所需时间极长。不同之处 :粗齿紫萁的孢子和精子器大些、颈卵器成对着生、成熟配子体多数为雌雄异株、受精率极低。华南紫萁和粗齿紫萁的孢子及配子体发育特点与紫萁、分株紫萁、绒紫萁、桂皮紫萁的极为相似 ,它们既具有大量的原始性状 ,也具有少数进化性状 ,支持把紫萁科列入原始薄囊蕨纲的观点。此外 ,也从孢子和配子体性状方面说明了紫萁属是一个自然的分类群     

关于窄膜棘豆(Oxytropis moellendorffii Bunge)(豆科)的分类学研究

作者对窄膜棘豆(Oxytropis moellendorffii Bunge)的分类学处理提出了新的观点:通过对原产地标本、资料的研究,认为五台山棘豆(O. wutaiensis Tatewakiet Hurusawa)实际上是窄膜棘豆(O. moellendorffii Bunge),对其变种(O. wutaiensis Tatew akiet Hurusaw a var. glabrata Tatewaki et Hurusawa)也进行了归并;另外本文中发表一个新等级--西灵山棘豆(O. moellendorffii Bunge var. sylinchanensis(Franch.)G.Z.Qian)。     

棘豆属植物Oxytropis pseudoglandulosa化学成分研究

从棘豆属植物O.pseudoglandulosa的地上部分中分离得到2个芳香性酰胺类化合物和3个黄酮类化合物,经波谱学方法鉴定为N-苯乙基苯甲酰胺(N-phenylethyl-Benzamide,1),N-(2-羟基,2-苯乙基)肉桂酰胺(N-(2-hydroxy-2-phenylethyl)cinnamamide,2),5-羟基,7-甲氧基二氢黄酮(5-hydroxy-7-methoxyflavanone,3),5-羟基,7-甲氧基黄酮(5-hydroxy-7-methoxyttavone,4),7-羟基二氢黄酮(7-hydroxyflavanone,5).其中3个黄酮类化合物均为首次从该植物中分得.     

棘豆属（豆科）一新组

记载了棘豆属一新组。目前该组包括二个种,它们是：黄穗棘豆和绿黄棘豆。过去,国内的学都将黄毛棘豆与黄穗棘豆等同。而文中作者认为黄毛棘豆是黄穗棘豆的一个变种。另外异色黄毛棘豆被作为变种处理。绿黄棘豆是一个中国新分布种。     

The influence of within-stream disturbance on dissolved nutrient levels during spates

In rivers, variations in concentrations of many dissolved nutrients occur during spates. Increases are usually attributed to concentrated point or non-point inputs, and decreases to dilution associated with rainfall. Increased discharge disturbs sediments and benthic communities, but the effects of such disturbance on nutrient levels are difficult to isolate. Measurements of nutrient levels over three artificial spates revealed that substantial variations in dissolved organic carbon, dissolved phosphate, silicate, nitrate, and potassium levels could result from increased discharge in the absence of allochthonous inputs. Variations were closely related to peaks in suspended solids concentration or water height. Increases in biochemical oxygen demand and suspended bacteria also occurred. Variations in phosphate and silicate could be accounted for by a balance between release of ‘sediment interstitial water’ and exchange processes involving suspended and freshly exposed sediment. An increase in nitrate, during one spate, was probably due to a reduction in the effect of benthic denitrification. Small peaks in dissolved organic matter concentration were detected over each spate. We propose that within-stream disturbance is a factor which may contribute to variations in dissolved nutrient concentration during the rising hydrograph in natural spates.     

棘豆属一新种

多年生草本, 近无茎, 全株被黄色长柔毛。托叶短, 与叶柄相贴, 卵状三角形, 合生。叶长4~6cm, 被黄色长柔毛。小叶对生4~6 对, 草质, 长2.5~3.5cm, 线形, 上面无毛, 下面具贴伏柔毛, 顶端急尖, 边缘反卷。总状花序近伞形, 具2~6 花, 花序柄与叶近等长。苞片卵形, 长2~3mm, 被白色柔毛。     

山稻蝗不同地域种群染色体C带核型研究

对我国分布的山稻蝗OxyaagavisaTsai不同种群进行了染色体C带核型研究 ,并对山稻蝗武夷山种群染色体C带核型进行了深入探讨 ,分析了其带型特殊性及该种群与其它山稻蝗种群染色体C带核型的区别与联系。同时通过对山稻蝗与中华稻蝗Oxyachinensis (Thunberg)、日本稻蝗Oxyajaponica (Thunberg)的形态、分布及染色体C带核型等方面的比较 ,探讨了该 3个种之间的进化关系 ,认为作为稻蝗属中的大型种类 ,上述 3个种之间有着较近的亲缘关系。染色体带型的实验结果表明 ,中华稻蝗为较原始的种类 ,而日本稻蝗和山稻蝗则可能是由原始中华稻蝗进化而来 ,其中日本稻蝗L2染色体的形成是由于原始中华稻蝗该染色体常染色质部分异染色质化的结果 ,山稻蝗L2染色体则可能是由于原始中华稻蝗该染色体近端部的臂间倒位所致。通过对武夷山山稻蝗的研究 ,对日本稻蝗和山稻蝗之间的近缘关系进行了分析和讨论。     

中国兰科耳唇兰属补志

在《中国植物志》第18卷中记载了四种国产耳唇兰属Otochilua植物。其中的白花耳唇兰O.albus系根据某些植物学家的引证,而不是作者自己检视的标本。在第一作者近来的一次赴欧访问中,仔细检视了保存在那里的耳唇兰属标本,特别是Smith与Seidenfaden所引证的标本：Forrest 9493(E)、16168(K,E)、27753(K,P,E)与F．E．Younghusband s．n．(K)。其中只有F．E. Younghusband s．n．是真正的白花耳唇兰,其余的应是宽叶耳唇兰O．lancilabius和耳唇兰O．porrectus。作为对《中国植物志》第18卷的补充,本文对白花耳唇兰作了订正,并根据西藏标本进行了描述。     

亚洲玉米螟与欧洲玉米螟混生区的研究

生殖隔离试验、形态鉴定、网室内性信息素活性反应和食性试验的结果表明 :张家口苍耳中的玉米螟与新疆伊宁的欧洲玉米螟同种 ,而为害玉米的优势种与广东阳山的亚洲玉米螟同种。张家口为害玉米的种群中 ,有部分雄蛾对欧洲玉米螟性信息素及苍耳中的雌处女蛾具有反应。苍耳和玉米中的种群在玉米、谷子、高梁、苍耳、草和大马蓼等 6种寄主上均可产卵和取食为害 ,并能正常完成生活史。研究结果证实张家口为亚洲玉米螟和欧洲玉米螟混生区 ,而且在玉米中很可能有少量欧洲玉米螟与亚洲玉米螟混生。     

青海固沙草属的两个新纪录种

首次报道了青海固沙草属2 新记录种--固沙草和鸡爪草, 并对两种植物地理分布上过去的不完善认识进行了分析, 编制了区分该属4 种植物的分类检索表, 同时引证了存于中国科学院西北高原生物研究所两记录种的全部考证标本。     

Microsatellite marker based genetic linkage maps of Oreochromis aureus and O. niloticus (Cichlidae): extensive linkage group segment homologies revealed

Partial genetic linkage maps, based on microsatellite markers, were constructed for two tilapia species, Oreochromis aureus and Oreochromis niloticus using an interspecific backcross population. The linkage map for O. aureus comprised 28 markers on 10 linkage groups and covered 212.8 CM. Nine markers were mapped to four linkage groups on an O. niloticus female linkage map covering 40.6 CM. Results revealed a high degree of conservation of synteny between the linkage groups defined in O. aureus and the previously published genetic linkage map of O. niloticus.     

腹部手术及丽珠肠乐对肠道双歧杆菌的影响

腹部手术及丽珠肠乐对肠道双歧杆菌的影响华西医科大学外科教研室成都６１００４１王学,吴言涛,严律南华西医科大学传染病教研室范昕建,朱淑媛,俞汝佳华西医科大学附一院门诊部胡泽芬宿主患病可减少肠道双歧杆菌的数量［１］。外科手术也可改变体内的生态环境,可能使...