RELATIONSHIP OF TAXA IN THE GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. III. M. ASCHERSONIANA × M. LACINIATA

1968 ◽  
Vol 10 (4) ◽  
pp. 777-781 ◽  
Author(s):  
K. Lesins ◽  
A. Erac
Keyword(s):  
Pollen Viability ◽  
Segregation Ratio ◽  
Length Ratio ◽  
Petiole Length ◽  
Relationship Of

The following evidence from hybridization studies indicated that M. aschersoniana Urb. and M. laciniata (L.) Mill. should be considered varieties, namely, (1) a simple (3:1) segregation ratio for laciniate vs. entire leaf, the latter being inherited as a recessive; (2) a 15:1 segregation ratio for peduncle/petiole length ratio, the short peduncle being inherited as a recessive; (3) pollen viability as high as that of the parental stocks; (4) unimpaired survival of F2 plants. In crosses between two different M. laciniata accessions the pod shape segregated in a 3:1 ratio, the conical pod shape being inherited as a recessive.

scholarly journals Phenotypic Correlations among Pollen Quality and Morphological Traits of Saintpaulia

2015 ◽  
Vol 7 (2) ◽  
pp. 198-202
Author(s):  
Erzsebet BUTA ◽  
Maria CANTOR ◽  
Rodica POP ◽  
Denisa HORȚ ◽  
Radu E. SESTRAS
Keyword(s):  
Morphological Traits ◽  
Significant Positive Correlation ◽  
Pollen Viability ◽  
Petiole Length ◽  
Growth Indices ◽  
Park Avenue ◽  
Number Of Leaves ◽  
Positive Correlations ◽  
Solid Nutrient Medium ◽  
High Length

In order to estimate the correlation between pollen viability, germination and the morphological traits, 15 Saintpaulia genotypes were analysed. Pollen viability was obtained by staining with potassium iodide (25%) and germination was estimated using solid nutrient medium (15% sucrose, 85% humidity, 22 °C temperature). Several morphological traits such as number of flowers, diameter of leaves rosette, number of leaves, length and width of leaves and petiole length were evaluated to determine growth indices. The results obtained indicated that ‘Hot Pink Bell’ genotype achieved the highest number of flowers and the largest diameter of leaves rosette. Genotypes ‘Tomahawks’ and S. grotei recorded the highest number of leaves. Higher width of leaves values was obtained in ‘Aloha Orchid’, while genotype ‘Park Avenue Blue’ was noted for a high length of leaves. Positive correlations were recorded among viability and germination in S. jonantha, S. rupicola and S. grotei. Significant positive correlation was registered between pollen viability and the number of flowers, but also between germination and the number of flowers per plant. The results indicated a possible correlation between viability, germination capacity and the morphological traits in most genotypes studied.

Underdeveloped embryos in dwarf seeds and implications for assignment to dormancy class

2005 ◽  
Vol 15 (4) ◽  
pp. 357-360 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Seed Dormancy ◽  
Evolutionary Relationship ◽  
The Other ◽  
Length Ratio ◽  
Morphophysiological Dormancy ◽  
Physiological Dormancy ◽  
Radicle Emergence ◽  
Relationship Of ◽  
Embryo Length ◽  
Morphological Dormancy

Studies were conducted to determine if small embryos (i.e. low embryo length:seed length ratio) in mature dwarf seeds (0.2–2 mm) are underdeveloped. In this case, they would grow (inside the seed) prior to germination, and seeds would have morphological or morphophysiological dormancy. Prior to radicle emergence, embryo length in seeds of Drosera anglica (Droseraceae), Campanula americana, Lobelia appendiculata, L. spicata (Campanulaceae) and Sabatia angularis (Gentianaceae) increased 0, 103, 182, 83 and 57%, respectively. Since embryo growth did not occur in seeds of D. anglica prior to germination, embryos, although small, are fully developed; seeds have only physiological dormancy. The underdeveloped embryo in seeds of C. americana has little or no physiological dormancy; thus, seeds have morphological dormancy. On the other hand, underdeveloped embryos in seeds of L. appendiculata, L. spicata and S. angularis are physiologically dormant, and seeds have morphophysiological dormancy. Therefore, since small embryos in dwarf seeds may or may not be underdeveloped, assignment of seeds to a dormancy class requires that studies be done to determine if embryos grow inside the seed before germination can occur. Such information is important in understanding the evolutionary relationship of the different kinds of seed dormancy.

RELATIONSHIP OF TAXA IN GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. IV. M. HYBRIDA × M. SUFFRUTICOSA

1969 ◽  
Vol 11 (2) ◽  
pp. 340-345 ◽  
Author(s):  
K. Lesins
Keyword(s):  
Pollen Viability ◽  
Cumulative Effect ◽  
Glandular Hairs ◽  
Good Pollen ◽  
Affinity Groups ◽  
Relationship Of

Medicago hybrida Trautv. and M. suffruticosa Ram. are closely related, as indicated by their ease of hybridization, by the vigor and fertility of the F1, and by good pollen viability (94–98%) in the F1. In the F2, glandular hairs on pods vs. no-hairs segregated in a normal, 1:3 ratio; hairiness of M. suffruticosa was recessive to no-hair condition of M. hybrida. Coiling of pods was determined by six dominant, non-linked factors, A1–A6, with cumulative effect. M. suffruticosa possessed the dominant alleles. Neither M. hybrida nor M. suffruticosa could be hybridized with the M. sativa-falcata group, indicating their membership in different affinity groups. M. leiocarpa Benth. could be crossed with M. hybrida as well as with M. suffruticosa. Further study is needed to determine whether the M. hybrida-suffruticosa group belongs to the genus Medicago or Trigonella.

Early detection of dwarf off-types from micropropagated Cavendish bananas

1993 ◽  
Vol 33 (5) ◽  
pp. 639 ◽  
Author(s):  
MK Smith ◽  
SD Hamill
Keyword(s):  
Early Detection ◽  
Plant Height ◽  
Selection Criteria ◽  
New Guinea ◽  
Length Ratio ◽  
Petiole Length ◽  
Musa Sp ◽  
Subgroup Selection ◽  
Selection Of

A method was developed for early detection of dwarf off-types from micropropagated bananas (Musa sp., AAA Group, Cavendish subgroup). Selection of dwarfs was from glasshouse-grown plants, and although differences between dwarf and normal plants could be detected as early as 3 weeks from deflasking, discrimination was most effective at week 7, when the normal plants had reached a height of 18-20 cm. In order to develop selection criteria, known dwarf off-types and normal plants were micropropagated and established in a glasshouse. Measurements included plant height, petiole - - length, lamina length and width, and distance between leaves. Petiole length, lamina length, and the petiole to lamina length ratio provided the most promising selection criteria, with the dwarfs having significantly (P<0.01) smaller petioles and leaves than the normal plants. Selection was most effective when the plants were growing vigorously and uniformly. When growth became limiting, selection was more difficult. This was particularly apparent in plants that required repotting into larger containers and in micropropagated bananas grown in nurseries under suboptimal conditions. Plants were grown in the field and observed at bunch emergence, to verify trueness to type and to eliminate the possibility that off-types may have arisen in the normal and dwarf populations. A survey of these selection criteria with other Cavendish cultivars of various statures was also completed and the results suggest that dwarf and extra-dwarf off-types could be readily separated from the taller Cavendish cultivars Williams, New Guinea Cavendish, and Grande Naine.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

Organization of transcription and pre-mRNA splicing within the mammalian cell nucleus

1995 ◽  
Vol 53 ◽  
pp. 768-769
Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin
Keyword(s):  
Rna Polymerase Ii ◽  
Cell Nucleus ◽  
Functional Organization ◽  
Mrna Splicing ◽  
Splicing Factors ◽  
Interchromatin Granule Clusters ◽  
Interchromatin Granule ◽  
Nuclear Regions ◽  
Relationship Of ◽  
Perichromatin Fibrils

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.

Locating Al in the DABCO catalyst before and after Al extraction

1990 ◽  
Vol 48 (4) ◽  
pp. 265-267
Author(s):  
Kathleen B. Reuter
Keyword(s):  
Active Site ◽  
Inverse Relationship ◽  
Transverse Direction ◽  
Reaction Rate ◽  
Acid Phosphate ◽  
Fracture Surfaces ◽  
Al Content ◽  
Before And After ◽  
Relationship Of

The reaction rate and efficiency of piperazine to 1,4-diazabicyclo-octane (DABCO) depends on the Si/Al ratio of the MFI topology catalysts. The Al was shown to be the active site, however, in the Si/Al range of 30-200 the reaction rate increases as the Si/Al ratio increases. The objective of this work was to determine the location and concentration of Al to explain this inverse relationship of Al content with reaction rate.Two silicalite catalysts in the form of 1/16 inch SiO2/Al2O3 bonded extrudates were examined: catalyst A with a Si/Al of 83; and catalyst B, the acid/phosphate Al extracted form of catalyst A, with a Si/Al of 175. Five extrudates from each catalyst were fractured in the transverse direction and particles were obtained from the fracture surfaces near the center of the extrudate diameter. Particles were also obtained from the outside surfaces of five extrudates.

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