大豆籽粒蓝脐性状及其分离规律

控制大豆白花亲本籽粒脐色的基因有带Ｒ与ｒ之分,带Ｒ基因的白花产本与紫花亲本杂交,Ｆ１代籽料出现蓝脐性状,其基因型为Ｉ－Ｒ－Ｗ１－ｔｔ。当控制脐色的基因有两对相差时（Ｒ、ｒ;Ｗ１、ｗ１）Ｆ２代籽粒脐色分离蓝脐与无色脐之比为９∶７。     

Identification and characterization of ten new water gaps in seeds and fruits with physical dormancy and classification of water-gap complexes

Background and Aims

Physical dormancy (PY) occurs in seeds or fruits of 18 angiosperm families and is caused by a water-impermeable palisade cell layer(s) in seed or fruit coats. Prior to germination, the seed or fruit coat of species with PY must become permeable in order to imbibe water. Breaking of PY involves formation of a small opening(s) (water gap) in a morpho-anatomically specialized area in seeds or fruits known as the water-gap complex. Twelve different water-gap regions in seven families have previously been characterized. However, the water-gap regions had not been characterized in Cucurbitaceae; clade Cladrastis of Fabaceae; subfamilies Bombacoideae, Brownlowioideae and Bythnerioideae of Malvaceae; Nelumbonaceae; subfamily Sapindoideae of Sapindaceae; Rhamnaceae; or Surianaceae. The primary aims of this study were to identify and describe the water gaps of these taxa and to classify all the known water-gap regions based on their morpho-anatomical features.

Methods

Physical dormancy in 15 species was broken by exposing seeds or fruits to wet or dry heat under laboratory conditions. Water-gap regions of fruits and seeds were identified and characterized by use of microtome sectioning, light microscopy, scanning electron microscopy, dye tracking and blocking experiments.

Key Results

Ten new water-gap regions were identified in seven different families, and two previously hypothesized regions were confirmed. Water-gap complexes consist of (1) an opening that forms after PY is broken; (2) a specialized structure that occludes the gap; and (3) associated specialized tissues. In some species, more than one opening is involved in the initial imbibition of water.

Conclusions

Based on morpho-anatomical features, three basic water-gap complexes (Types-I, -II and -III) were identified in species with PY in 16 families. Depending on the number of openings involved in initial imbibition, the water-gap complexes were sub-divided into simple and compound. The proposed classification system enables understanding of the relationships between the water-gap complexes of taxonomically unrelated species with PY.     

Seed-coat structure and anatomy of some Nigerian pulses

Here we report the seed morphology and anatomy of some Nigerian pulses, an investigation that revealed a wide diversity of characteristics in a small collection of seeds. Although these genera share common features, their anatomical differences make it possible to generate a key for identification and classification. Sizes ranged from 5 to 7 x 5 x 3 mm forCajanus cajan up to 25 to 30 x 18 x 19 mm forCanavalia ensiformis. Seed colors were monochromatic black/brown to dichromatic eye/mottled (streaked), and surfaces were either smooth-glossy or puckered. Forms varied from ellipsoid or oblong-ellipsoid to spheroid or reniform, and halos (hilar rims) were either complete or incomplete. Lens shapes were spot, linear, broadly linear, or deltoid. The hila were elliptic to linear (or in-between), with sizes ranging from 0.5 to 1.0 mm (Mucuna pruriens) up to 1.5 to 3.0 mm (Phaseolus vulgaris). Their positions could be completely covered, as inP. vulgaris, partially covered and raised above the seed surface (Vigna subterranea), or naked (without any funicular residue) arid level with the surface, as in Gensiformis (Tce1 ). The aril caps were collar-like inLablab purpureus or cushion-like, as inM. pruriens. Palisade cell sizes ranged from 80.7pm inGlycine max to 1733 μm inC. ensiformis (Tce1), and their shapes varied from a uniformly wall-thickened type (T₁), to a bulbous-end type (T₂), to one with a corrugated structure on the inner wall (T₃). Although these anatomical variations exist, they may not warrant demarcation into sub-familiar or generic classifications. However, we do propose that specific and sub-specific alterations are necessary.     

Production and morphology of fruit and seeds in Genisteae (Fabaceae) of south-west Spain

The productivity and morphology of fruit and seeds were studied in 30 species (and subspecies) of the tribe Genisteae (Fabaceae) in south-west Spain. The morphological characters of greatest taxonomic value both for the segregation of the two subtribes (Genistinae and Lupininae) recognized in Genisteae and for the delimitation of the lower taxonomic levels (genus and species) are the size of the pod and characters of the pericarp, the colour and weight of the seeds, whether or not an ad exists, and the shape, size, and position of the hilum. In contrast, characters of little taxonomic interest are pod colour, shape and number of seeds, and characters of the lens. There were also found to be major relationships between fruit and seed, and between these and other floral (e.g. corolla size) or reproductive (e.g. polledovule [P/O] and seed/ovule [S/O] ratios) attributes. Thus in this tribe, pod size was positively correlated with corolla size, seed size, the number of viable seeddfruit, and the S/O and P/O ratios. Corolla size was positively correlated with the number of viable seeds/ fruit and with the seed weight. Similarly, the number of seeddfruit was positively correlated with the fruit's weight and with the number of ovules/ovary. Also, the weight of the seeds was positively correlated with the pollen/ovule ratio. There was also positive correlation between the S/O and P/O ratios.     

长豇豆种皮和种脐的发育

长豇豆的胚珠具内外两层珠被,内珠被在种子发育早期退化消失,种皮仅由外珠被发育而成。外珠被的外表皮细胞径向伸长,外壁和经向壁增厚,形成约占成熟种皮厚度一半的栅栏层;亚表皮细胞发育为骨状石细胞层。第三层细胞类似于亚表皮层但细胞壁增厚不明显,其内方的多层薄壁细胞形成海绵组织。种脐具两层栅栏细胞,外栅栏层及其以外部分由珠柄组织发育而成管胞群。本文还对脐缝和管胞群的作用以及豆科种子的吸水机制进行了讨论。     

Species separation in <Emphasis Type="Italic">Curvularia</Emphasis> “geniculata” group inferred from <Emphasis Type="Italic">Brn1</Emphasis> gene sequences

 Brn1, a reductase gene involved in the melanin biosynthetic pathway, was adopted for species delimitation among members in the “geniculata” group of Curvularia species and proved to be useful for this purpose. Phylogenetic trees of these fungal members were constructed from nucleotide sequences of this region. The so-called geniculata group of Curvularia was separated into several clusters. The conidial morphology of the members in each cluster is closely similar but clearly different among discrete clusters. The phylogenetic groups almost concurred with the morphological grouping. Thus, the synonymous treatment of Curvularia affinis, C. fallax, and C. senegalensis to C. geniculata in a previous study was supported. The isolates with warping hilum conidia were clearly different from C. geniculata and separated into two clusters. C. geniculata ATCC 6671 made an independent cluster situated near these clusters. The protuberant hilum species were located separately in the phylogenetic trees. For sound taxonomic treatment of these isolates, we should accumulate more information and retain our species determination for them. Received: September 26, 2002 / Accepted: March 12, 2003     

香烟烟雾水溶物诱发蚕豆根尖细胞微核的研究

本文研究了不同浓度的香烟烟雾水溶物对蚕豆根尖细胞微核的诱变作用,结果表明, 上述水溶物能够引起蚕豆根尖细胞微核率发生敏感性变化,提示蚕豆根尖细胞微核技术可作为一种香烟遗传毒理学检垛方法使用。此外,还对使用该方法的意义以及添加VE对香烟烟雾水溶物微核率的影响进行了讨论。     

Surface Ultrastructure of Seeds of Chinese Cuscuta

The surface ultrastructure of seeds of chinese Cuscuta was observed under SEM. The main results are as follows: the seed surface could be divided into three parts: hilum, hilum-rim and spermoderm. The hilum is collar-shaped or higher or lower than level of hilum-tim. Hilum-rim cells are mostly radiately arranged and less frequently in reticulate or other types of arrangement. The spermoderm shows at least three patterns of ornamentation, cerebelloid, striate or irregular, on which some tuberculate or small clumps of granules could be found sometimes According to the surface ultrastructure of the hilum, hilum-rim and spermoderm, the observed dodder seeds could be divided into three types. The surface characters of dodder seeds are also important both for diagnosis ofspecies and for quarantine of dodders.