赤松不定根和愈伤组织与松口蘑外生菌根菌的相互作用

本实验报道了以简单的离体培养方式来诱导赤松不定根和愈伤组织与松口蘑的菌根反应。不定根和愈伤组织均起源于无菌苗的下胚轴,接种2周后,菌丝体开始包围不定根。接种3周后,菌丝体出现在不定根皮层细胞间,哈蒂氏网型的形成也同时被确认。在愈伤组织培养物中,细胞间也能观察到菌丝体及拟-哈蒂氏网结构。这是第一个离体条件下成功地诱导赤松培养组织与松口蘑形成外生菌根的报道。     

云杉核型的研究兼论云杉属的进化地位

本文分析了我国特产树种云杉Picea asperata的核型,K(2n)=24=20m+4sm,属2A类型,染色体相对长度组成为2n=24=2L+12M_2+SM_1+2S。云杉属植物(22种、变种)的核型全由臂比小于2的中部和近中着丝粒染色体构成,是较为原始的核型。根据松科各属核型的比较,作者讨论了云杉属的亲缘关系和进化地位,并得到形态学、解剖学、孢粉学、植化学、生化学及古植物学等的支持。     

INTERACTION BETWEEN HELIANGINE AND PYRIMIDINES IN ADVENTITIOUS ROOT FORMATION OF PHASEOLUS CUTTINGS

1. Heliangine at 110^–4 M promoted the adventitious rootformation in hypocotyls of cuttings taken from light-grown (1,900lux) Phaseolus mungo seedlings. The promotion was almost completelyreversed by 310^–4 M uracil, uridine, cytidine, oroticacid or 610^–4 M carbamoyl DL-aspartic acid, and partlyby 310^–4 M thymine or thymidine. Neither 310^–4M cytosine, adenine, adenosine, guanine, guanosine nor a combinationof 310^–4 M carbamoyl phosphate and 310^–4 M L-asparticacid reduced the promotion by heliangine.
2. Uracil did not reducethe inhibiting effect of heliangine onthe indoleacetic acidinduced elongation of etiolated Avenacoleoptile sections.
3. Helianginein an aqueous uracil solution was recovered unchangedafter24-hr incubation at room temperature.
4. The root formation ofPhaseolus cuttings was promoted also by2-thiouracil and 5-fluorouracil.The effect was reversed byorotic acid or carbamoyl asparticacid, but not by carbamoylphosphate plus aspartic acid.
5. Ribonucleaseat 100 µg/ml increased the number of rootsprotruded fromhypocotyls of cuttings by about 260%.
6. A possible interpretationfor the promotion of root formationby heliangine is offered.

¹ Contribution No. 15 from the Botanical Gardens, Faculty ofScience, University of Tokyo, Tokyo, Japan. ² Dedicated to Prof. Dr. H. SODING in commemoration of the 70thbirthday.     

LIGHT AND ELECTRON MICROSCOPE STUDIES OF THE CELL WALL STRUCTURE OF THE ROOT HAIRS OF RAPHANUS SATIVUS

Dawes , Clinton J., and Edwin Bowler . (U. of California, Los Angeles.) Light and electron microscope studies of the cell wall structure of the root hairs of Raphanus sativus. Amer. Jour. Bot. 46(8): 561–565. Illus. 1959.—The structure and development of the cell wall of the root hair of Raphanus sativus were studied under the light and electron microscopes. The outer layer of the root hair consists of mucilage which covers the entire hair and forms a thick cap at the tip. Beneath the mucilage a thin cuticle covers the inner layers of the cell wall. These layers consist of cellulose microfibrils, varying in pattern, in a granular matrix, presumably pectic in nature. The microfibrils of the outer layer, apparently laid down at the tip, are reticulate in arrangement. In mature regions of the root hair, the wall is thickened by an inner layer of parallel and longitudinally orientated microfibrils. Pores in the cellulose wall are evident and increase in number and size near the base of the hair.     

HISTOLOGY AND INHERITANCE OF THE CLOSED FLOWER IN CARTHAMUS TINCTORIUS (COMPOSITAE)

Three different closed flower types were identified in safflower and were classified as arrowhead, bar, and cage. Histological observations revealed that the closed flower condition is caused by a differentiation of epidermal cells into papillae that become interdigited. The primary difference between the three types is the length of the fused edge along the petal lobe. The papillae are pointed and have thickened walls of cutin. Reduced seed set results from changes in the internal environment during microsporogenesis. The expression of each closed flower type is governed by a single gene; the arrowhead, bar, and cage types have, respectively, the genotypes arar, baba, and coca.     

雪松属的细胞分类学及历史植物地理学研究

雪松属含雪松,北非雪松、黎巴嫩雪松和短叶雪松等４种,它们间断分布于西北喜马拉雅、西北非及西亚。本文分析了雪松的核型,Ｋ（２ｎ）＝２４＝１８ｍ＋６ｓｍ,该结果与Ｈｉｚｕｍｅ（１９８８）的一致但不同于Ｍｅｈｒａ＆Ｋｈｏｓｈｏｏ（１９５６）的。作者比较了雪松属３个代表种的核型并提出了它们的进化趋势可能是雪松→北非雪松→黎巴嫩雪松。从松科各属核型的比较分析,作者认为将雪松属由落叶松亚科分出置于冷杉亚科是合乎需要的。根据细胞学、化石、地理分布、古地理和古气候等资料,本文还讨论了雪松属的起源、迁移和进化。     

表面活性剂与脂质体相互作用的~(31)P核磁共振研究

(31)~P—NMR实验表明,小的超声囊受表面活性剂Tween80或TritonX—100作用后磷脂头部基团的运动受到限制,可能与磷脂的磷酸根和水化的表面活性剂分子通过氢键的相互作用有关。多层脂质体加Triton X—100后显示各向同性运动,提示表面活性剂可诱发双层结构的改变。     

红皮云杉茎的解剖结构与插条不定根形成的研究

１９９２年７－８月定时固定红皮云杉插条基部材料于ＦＡＡ液中,石蜡制片法室内解剖研究不定根的发生。结果表明：红皮云杉插条诱发根原基的来源有两种途径。一种是愈伤组织生根型,在愈伤组织的再生形成层处,或茎的维管形成层诱发根原基;另一种是非愈伤组织生根型,在插条切口处的维管形成层、皮层或初生木质部与次生木质部间的薄壁组织较深的部位,直接产生纵向不定根原始体,有的在距离切口０．１－０．５ｃｍ以上茎的维管形成层,维管形成层与木射线的交界处及叶隙等薄壁组织产生径向不定根。不同个体间产生的不定根数量及发育的早晚差异较大。