十七种一变种美登木叶片解剖与分类的关系

我们从国内外收集美登木属17种1变种,从叶片外部形状及内部结构进行比较,,发现在美登木属17种1变种美登木叶片组织中存在两种晶体(簇晶和方晶),可把美登木属分成三大类,一类具簇晶,二类具方晶,三类具簇晶和方晶。然后根据晶体的大小及其在组织中的分布部位,又将本属中的种分开。另外我们从美登木叶片解剖发现,成熟叶主脉横切面维管束的形状常是固定的,它不受外界环境的影响,也不受地理位置的影响,如滇南美登木分别采自云南省景洪和耿马不同地区不同生境,成熟叶横切面上维管束形状是相同的。成熟叶横切面上维管束的形状较稳定。所以用细胞内的晶体类型和维管束的形状把美登术属不同种进行分类是有意义的。     

THE EFFECT OF STRYCHNINE AND LIGHT ON PIGMENTATION IN BLEPHARISMA UNDULANS STEIN

The effect of strychnine sulfate and light on pigmentation in the ciliate protozoan Blepharisma undulans has been determined. Upon exposure of cells to strychnine, the pigment granules become loosened from their surrounding membranes. Eventually these membranes break and the granules are simultaneously released from the cell. At the cell surface, a fusion occurs between adjacent membraneless granules with the incorporation of membrane fragments. This fusion of granules and membrane fragments results in the formation of a pigmented "capsule" around the organism. After elimination of the pigment, the granule membranes remaining in the cytoplasm fuse to form apparently empty vesicles. Other cell organelles are generally undisturbed. A similar situation occurs upon exposure of cells to artificial light for 12 to 18 hr, however, the slow elimination of granules from the cells under these conditions does not result in the formation of a pigmented "capsule." The possible mechanisms of these reactions are discussed.     

辽宁省番茄花叶病主要病毒和株系的研究

从辽宁南部及沈阳地区采集番茄花叶病样本111个(1985-1987),经鉴定得知主要毒原为番茄的烟草花叶病毒(TMV)占总调查的59.46％。黄爪花叶病毒(CMV)亦有发生仅占总调查的9.00％。还有一些系混合侵染(TMV和CMV)占21.62％。尚未认清毒原种的约占2.70％,接种无症的占7.20％。通过试验认为我省番茄上主要毒原为烟草花叶病毒,并进行了常规鉴定、提纯、电镜观察、光谱测定和血清测定等。对番茄上烟草花叶病毒16个分离物做了株系分化研究,按照Pelbam(1970,1972)〔14、15、16、17〕的抗性分类法应用番茄GCR一套品种接种观察,得知辽南及沈阳地区分布很广的番茄TMV分离物,均属TMV-O株系。故在番茄抗TMV育种中尚应考虑到抗1及2株系的能力。     

采后荔枝果实中氧化和过氧化作用的变化

采后的荔枝（Litchi chinensts)果实的果皮和果汁中的抗坏血酸及果汁的谷胱甘肽含量逐渐下降,果皮的谷胱甘肽甘肽含量先增多（采后3天）接着减少,超氧化物歧化酶活性随采后时间加长而降低,膜脂过氧化产物丙二醛及过氧化物酶活性显著增高,采收7天后果皮中丙二醛含量增加2倍,过氧化物酶活性增高6－7倍,超氧物歧化酶活性只为原来的44％,内源清除活性氧能力的减弱与膜脂过氧化产物的积累表明,荔枝果实的衰老与活性氧的伤害有关,过氧化物酶活性增高可作为果实衰老的一个指标。