SOME EFFECTS OF GAMMA IRRADIATION ON SEEDS AND RHIZOMES OF MUSA

The tolerance of Musa balbisiana Colla seeds to gamma irradiation was found to be considerably greater than that of rhizomes of the parthenocarpic variety ‘Gros Michel': e.g., 11.8 krad reduced the germination of rhizomes 92% and of seeds approximately 15%. Intact seeds exposed to doses higher than 48 krad did not germinate in non-sterile soil, but, when scarified and cultured axenically after irradiation, seeds which received doses as high as 70 krad germinated. Embryos excised from seeds exposed to doses as high as 285 krad formed callus, indicating that not all metabolic processes were inhibited by these extremely high doses. There was considerable variation in radiation tolerance between seed lots which was not related to their age, moisture content, or pre-exposure viability. Germination of intact seeds appeared to be stimulated by doses of 3 or 9 krad. No lasting differences attributable to the level of irradiation were apparent in the development of seedlings derived from either intact or scarified seeds nor of plantlets derived from excised embryos. Conversely, there was a significant reduction, proportional to irradiation dose, in the growth of plants developing from rhizomes, emphasizing the greater radiation sensitivity of the vegetative propagule. The radiation tolerance of seed-borne microorganisms was considerably higher than that of the plant materials, indicating that gamma irradiation is not effective as a means of obtaining pathogen-free rhizomes or surface-sterilizing seeds of M. balbisiana.     

我国睡莲科花粉形态的研究

本文对我国睡莲科5属11种2变种的花粉形态进行了系统的研究。每种花粉都通过光学显微镜和扫描电镜进行观察和照相。同时对莲和白睡莲二种花粉作了超薄切片,对它们的外型结构进行了透射电镜的观察和照相。并结合有关分类学和孢粉学资料,讨论了本科的原始性、异质性及演化上的问题。     

SOME ABNORMAL FLOWERS OF ARGEMONE MEXICANA AND THEIR BEARING ON THE MORPHOLOGY OF THE GYNOECIUM OF PAPAVERACEAE

Abnormal flowers of Argemone mexicana are described in whichthe gynoecium has been transformed into a cup with lobed marginor into free leafy carpels. The number of lobes or leafy carpelsin such gynoecia is found to vary from three to five. This agreeswith the general view of systematists regarding the number ofcarpels composing the gynoecium in this species, and is againstthe views of Saunders and Dickson who postulate twice as manycarpels.     

我国某些蔷薇属花卉的核型研究

本文报道了我国产的5种和14个品种的蔷薇属花卉的染色体数目和核型,结果如下:小花型为二倍体,2n=2x=14,少数为混倍体;中花型为三倍体,2n=3x=21;大花型为四倍体,2n=4x=28。大部分种的核型均由其中部和近中部着丝点染色体组成,少数种具近端着丝点染色体。它们可以区分为3种核型类型,即1A、2A和1B。     

睡莲科的属间关系研究

本文用谱系分支法分析睡莲科的属间关系,３５个衍征中,分析了３１个特征的进化趋势,根据分析将睡莲科提升为睡莲目,分为３个科,莲科、水盾草科、睡莲科。     

被子植物的花化石研究

五十多年前胡骕在研究山东临朐县山旺组的植物化石中,发现有花的化石,仅保存了5个花瓣或仅5个萼片,均难给予确切的分类位置;六十年代我们两次去山旺野外工作,发现为数较多,同样仅保存花瓣或萼片的化石。本文研究的是80年代发现并保存较为完好的花化石。新近李凤麟详细论述了各门类化石,均认为山旺组的地质时代属中中新世。近十余年来,国际上被子植物的花化石的研究进展较快。每次花化石的发现,对研究被子植物种系发生、系统位置及在地史中的演化及演变速率等均是极重要     

睡莲科的核型分析及其分类学位置的探讨

本文对睡莲科6属6种代表植物的核型进行了研究,并探讨了它的分类学位置。结果如下：莲2n＝16=9sm+4m+3st;王莲2n＝24=8sm+8m+8T,蓝睡莲2n＝28,可配成14对,染色体小,第l号染色体上有2条随体;萍蓬草2n＝34＝18m+16sm;芡实2n=58,可配成29对,染色体小,第l号染色体有2条随体,莼菜2n＝72,可配成36对,染色体按大小可分成大,中、小三个类别。除莲外,其它5种植物的核型为首次报道。莼菜的体细胞染色体数目2n＝72和国外报道的2n＝80不相一致。莲的染色体以及形态学特征和其它睡莲科分类群显著不同,可将其从睡莲科中独立出来,并成立莲科和莲目。原归属于睡莲科的分类群仍组成睡莲目,并分别置于莼菜科和睡莲科。     

中国产瓦韦属植物叶柄与根状茎的比较解剖研究

详细观察了已发表的60种瓦韦属植物叶柄和根状茎的横切面。瓦韦属植物叶柄维管束条数最多7条,最少2条,其中2个较粗,其余较细,排成一字型、三角型、四角型、半轮型等。根状茎上的维管束条数最少5条,最多16条,属于网状中柱,维管束不规则环形排列,夏绿种类厚壁组织较少或没有,常绿种类厚壁组织较多。叶柄与根状茎的研究对瓦韦属组的划分和种的确立有重要的参考价值。参考这些特征,瓦韦属相应地划分成六个组,即:大叶瓦韦组、扭瓦韦组、瓦韦组、革质叶瓦韦组、纸质叶瓦韦组、网眼瓦韦组。一些种类相应地进行了合并。     

ENVIRONMENTAL EFFECTS ON THE DIFFERENTIATION OF ABNORMAL COTTON FLOWERS

Previous studies have shown that both genes and cytoplasm have important effects on the number of anthers and external ovules borne by the staminal columns of flowers on plants with the EO gene. Under Mississippi Delta conditions a single plant may produce flowers daily for three months or more. The basic premise for the study reported here was that each of these 100-200 flowers of a single plant exposed a constant gene-cytoplasm combination to an extremely variable environment. Highly significant correlations with environment were found as follows: Number of anthers with relative humidity 22 days before anthesis, number of external ovules with minimum temperature 19 days before anthesis, and percentage of sterile anthers with maximum temperature 15-16 days before anthesis. The external ovule property thus permits study of flower differentiation by manipulating three different variables: (1) cytoplasm, (2) gene dosage, and (3) environment.     

THE NATURE OF THE DIRECTIVE INFLUENCE OF GRAVITY ON THE ARRANGEMENT OF ORGANS IN REGENERATION

1. When leaves of Bryophyllum calycinum are suspended in moist air in a vertical plane and sidewise, roots and shoots are formed exclusively or predominate in the notches on the lower side of the leaves. When pieces of stems of the same plant are suspended horizontally in moist air, roots develop on the lower side of the stem, with the exception of the extreme basal end where they may develop on both sides. 2. The writer has suggested in a preceding paper that this directive influence of gravity on the arrangement of the regenerating organs may be due to the combination of two factors. The first factor is gravity, which causes a slightly greater collection of sap on the lower side of these organs, and as a consequence roots develop a little more quickly on the lower than on the upper side. The second factor is of an inhibitory character inasmuch as quite generally organs which grow out first, or which grow quickly, have a tendency to retard or inhibit the growth of similar organs in other places. 3. The writer was able to prove the action of this inhibitory factor by cutting off the lower edges of leaves suspended sidewise in a vertical plane or the lower halves of stems suspended in a horizontal plane (in moist air). In this case roots developed as abundantly on the upper side of these organs as they otherwise would have developed on the lower side. 4. It was, however, still necessary to prove the idea that gravity causes sap to collect in larger quantity in the lower parts of organs. This gap is filled by the present paper in which it is shown, first, that in the leaves suspended in moist air a red pigment is formed which has a tendency to collect gradually in the lowest parts of the leaf when the latter is suspended in a vertical plane. This red pigment serves as an indicator for the distribution of sap in the leaf and thus shows directly the tendency of the sap to collect in greater abundance on the lower edge of a leaf suspended in a vertical plane. Second, it is shown that when leaves or stems of Bryophyllum are suspended, in the way described, under water instead of in moist air, roots develop on the upper side as well as on the lower side. The directive effect of gravity upon the arrangement of organs disappears in this case since the abundance of the outside water makes the effect of a slight difference in the distribution of sap between the upper and lower side a negligible factor. Third, it is shown that the dry weight of the lower half of leaves suspended sidewise for several weeks in moist air in a vertical plane is greater than that of the upper half when roots and shoots are formed on the lower side only. This indicates that material from the upper half flows into the growing organs of the lower half. No such difference between upper and lower half of leaf is found when the leaves are suspended in the same way in water and roots and shoots are formed on both sides of the leaf. 5. It is shown that when a leaf connected with a piece of stem is suspended in moist air the red pigment goes into the stem instead of collecting in the lower part of the leaf, thus supporting the view expressed in a preceding paper that the inhibitory action of the stem on the root and shoot formation in a leaf of Bryophyllum is due to the fact that the material available in the leaf for organ formation is naturally sent into the stem.     

结香化学成分的研究

从结香(Edgeworthia chrysantha)的花蕾中分离得出3个香豆索,2个黄酮。用波谱等方法确定其结构为伞形花内酯(umbelliferone,1),6-甲氧基-7-羟基双香豆素-3,7’-醚(daphnoretin,2),7,7’-二羟基双香豆素-8,8’-醚-7-α-L-鼠李糖甙(edgeworoside c,5),4’,5,7-三羟基黄酮醇-3-O-β-D-(6′′-对羟基桂皮酰基)-葡萄糖甙(tiliroside,3),山萘酚-3-O-β-D-葡萄糖甙(kaempferol-3-O-β-D-glucoside,4),以上化合物均为首次从结香花蕾中得到。     

5种甘草根和根状茎的解剖学研究

５种甘草根和根状茎的比较解剖学研究表明,成长根都由周皮和维管组织构成,种间差异主要表现在木栓层和细胞层、韧皮纤维束和排列和轮数、导管分布频率、射线形成以及初生木质部在根中央的星散分布状况等方面;成长根状茎都由周皮、维管组织和髓构成,与根相比较根状茎具厚的木栓层、长而粗的导管分子稿的导管分布频率,不同种根状茎之间韧皮射线的形态和裂隙的有无以及髓、韧皮部含单宁细胞的数量、导管内含物等方面也存在一定差异     

高良姜中的抗氧化有效成分

从高良姜(Alpinia officinarum Hance)中分离了7个化合物,其中4个二苯基庚烷类化合物:1,7-diphenylhept-4-en-3-one(Ⅰ),7-(4”-hydroxy-3”-methoxyphenyl)-1-phenyl-hept-4-en-3-one(Ⅱ),5-hydroxy-7-(4”-hydroxy-3”-methoxyphenyl)-1-pheny-3-heptanone(Ⅲ),5-methoxy-7-(4”-hydroxy-3”-methoxyphenyl)-1-phenyl-3-heptanone(Ⅳ);3个黄酮醇类化合物;鼠李柠檬素(rhamnocitrin)(Ⅴ),山奈素-4’-甲醚(kaempferol-4’-methylether)(Ⅵ)及高良姜素(galangin)(Ⅶ)。用维生素C诱发肝微粒体脂质过氧化方法测定了以上化合物的抗脂质过氧化活性。黄酮醇类化合物具有较强的抗氧化活性,二苯基庚烷类化合物除化合物Ⅰ外都显示了中等强度的抗氧化活性。     

MORPHOLOGICAL STUDIES OF THE NYMPHAEACEAE. XI. THE FLORAL BIOLOGY OF NELUMBO PENTAPETALA

The floral biology of Nelumbo pentapetala (Walter) Fernald, the American lotus, native to Texas, was investigated. Anthesis occurs over three consecutive days with flowers opening each morning and closing around noon. First-day flowers are protogynous with the perianth parts partially expanded so that pollen-covered insects which are attracted by floral color and the intense “fruity” odor (diffused with the aid of increased floral temperature) are directed on to the flattened receptacle (= carpellary receptacle) from which the receptive stigmas protrude, thus accomplishing pollination. During the second morning anther dehiscence begins and insects which visit and forage within the flower become covered with pollen and typically crawl over the still receptive stigmas achieving “facilitated” self-pollination (indirect autogamy). By mid-morning of the second day the stigmas dry and become non-receptive to pollen. During the third day of anthesis perianth and staminal parts quickly abscise and over the period of a few weeks the receptacle and enclosed fruits mature. In most populations studied, Hymenoptera (e.g., Lusioglossum spp., and Apis mellifera) were the most abundant and effective pollinators. In some populations, however, Coleoptera (e.g., Chauliognathus) were also numerous and effective pollinators. It is suggested that the overall floral structure (e.g., large numbers of stamens, masses of pollen, staminal appendages) are adaptations which facilitate the pollination of Nelumbo by beetles.