An S-RNase promoter from Nicotiana alata functions in transgenic N. alata plants but not Nicotiana tabacum

Nicotiana tabacum and Nicotiana alata plants were transformed with genomic clones of two S-RNase alleles from N. alata. Neither the S ₂ clone, with 1.6 kb of 5 sequence, nor the S ₆ clone, with 2.8 kb of 5 sequence, were expressed at detectable levels in transgenic N. tabacum plants. In N. alata, expression of the S ₂ clone was not detected, however the S ₆ clone was expressed (at low levels) in three out of four transgenic plants. An S ₆-promoter-GUS fusion gene was also expressed in transgenic N. alata but not N. tabacum. Although endogenous S-RNase genes are expressed exclusively in floral pistils, the GUS fusion was expressed in both styles and leaves.     

Studies on the leaf anatomy of Euphorbia III. The node

Anatomical studies of representatives of 11 groups of species of the genus Euphorbia , erected on the basis of leaf venation patterns, reveal the occurrence of 3 main types of nodal organization, viz. unilacunar 1-trace, bilacunar 2-trace and trilacunar 3-trace (in the majority of the species). In some instances, a deceptive multi-stranded condition is visualized if cleared leaves alone are studied. Euphorbia polygonifolia and E. peplis leaves have a variable vascular supply in the same plant, consisting of 2 or 3 strands in the former and 2 or 4 strands in the latter. No correlation was found between the type of node and either the habit and habitat of the plant or the leaf shape and size.     

蕺菜属不同居群间比较解剖学研究

对采自四川、重庆、江苏等地蕺菜属的 2 5个不同居群间进行了较为全面的比较解剖学研究。结果表明 :蕺菜属不同居群间的根、地上茎、地下茎、叶等器官在解剖结构上存在较大差异。但峨眉蕺菜与蕺菜解剖结构的种间差异不明显。文中还对蕺菜属不同居群间解剖结构差异与质量间关系进行了探讨。     

Typification and redelimitation of Nepenthes alata with notes on the N. alata group,and N. negros sp. nov. from the Philippines

In the course of studies to typify what has been regarded as the most widespread and common of the endemic Philippines species of Nepenthes, N. alata Blanco, we were able to review the morphological variation in what we previously regarded as a polymorphic species. This led us to redelimit that species in a narrower sense, to resurrect N. graciliflora Elmer, and to recognise N. negros sp. nov., here assessed as ‘Critically Endangered’ (CR) using the IUCN standard. The Nepenthes alata group is characterised and a key to its species is provided.     

Leaf anatomy and chloroplast ultrastructure of Mn-deficient orange plants

Leaf samples of Mn-deficient and Mn-sufficient (control) ‘Navelate’ orange plants grown in a greenhouse were taken to investigate the effects of Mn deficiency in leaf structure and chloroplast ultrastructure. Total leaf chlorophyll concentration was significantly lower in Mn-deficient plants than in control ones. Entire lamina thickness was not altered due to Mn deficiency. However, Mn deficiency resulted in disorganization of mesophyll cells, mainly of palisade parenchyma cells. The number of mesophyll chloroplasts per cellular area and their length were both affected negatively. The membranous system of chloroplasts was also disorganized. The percentages of starch grains and plastoglobuli per chloroplast of Mn-deficient leaves were significantly greater than those of control leaves.     

水生维管植物研究:II、水生维管植物对干涸的适应

根据实地考察和文献分析 ,研究了水生维管植物对干涸的不同的适应对策 ,归纳为 3类 :(1 )直接适应型 (或称生理适应型 ) ;(2 )间接适应型 ;(3 )休眠适应型。这有助于认识水生植物的适应特征 ,揭示干涸对部分水生植被演替的作用。     

三种葱属植物花形态及花药解剖结构观察

蒙古韭(Allium mongolicum Regel)、细叶韭(Allium tenuissimum L.)、野韭(Allium ramosumL.)作为野生蔬菜近年来受到人们的青睐,一些学者对这三种葱属植物进行了初步研究,但对其解剖结构的研究未见报道.通过田间观察和石蜡切片法,对这三种葱属植物花的形态及花药解剖结构进行了观察,结果表明:三种葱属植物花的形态结构差异明显,花粉粒的形状及大小也有明显的差别:野韭花粉粒为长卵形,细叶韭为卵圆形,蒙古韭为近半圆形;从花粉粒大小来看,野韭最大,蒙古韭次之,细叶韭最小.通过以上研究揭示了三种葱属植物花药解剖学特征,从而为葱属植物分类标准、亲缘关系鉴定、生殖发育等方面的进一步研究提供理论依据.