scholarly journals Obtaining hybrids of cultivars and wild subspecies of cassava

2018 ◽  
Vol 53 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Dreid de Cerqueira Silveira da Silva ◽  
Márcio Lacerda Lopes Martins ◽  
Ariana Silva Santos ◽  
Vanderlei da Silva Santos ◽  
Alfredo Augusto Cunha Alves ◽  
...  
Keyword(s):  
Manihot Esculenta ◽  
Room Temperature ◽  
Male Parent ◽  
Controlled Crosses ◽  
Viable Seeds ◽  
The Moment

Abstract: The objective of this work was to evaluate the crossability between cassava (Manihot esculenta subsp. esculenta) cultivars and the subspecies M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana. Plants from the BRS Jari, BRS Formosa, BRS Verdinha, and BGM 2050 (Equador 72) cultivars were crossed with the two subspecies. During flowering, at pre-anthesis, pistillate flowers were covered with a nylon bag and staminate flowers on the same inflorescence were emasculated. The staminate flowers were collected and placed in flasks previously labeled and sterilized with alcohol; some fresh flowers were stored at room temperature due to asynchronous flowering. The crosses were made between 10 a.m. and 2 p.m. After pollination, the flowers were covered again. Evaluations were made from the moment of pollination to the dehiscence of the fruit. Of the total flowers pollinated, 38% were fertilized, and 504 developed fruits and 816 produced seeds were observed. As a male parent, M. esculenta subsp. flabellifolia is more efficient in crosses with M. esculenta subsp. esculenta and may be recommend for controlled crosses. The crosses between the cassava cultivars and M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana produce viable seeds.

Male germ line polysomy in the grasshopper Chorthippus binotatus: extra chromosomes are not transmitted

Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 384-388 ◽  
Author(s):  
M. Talavera ◽  
M. D. López-Leon ◽  
J. Cabrero ◽  
J. P. M. Camacho
Keyword(s):  
Natural Population ◽  
Sierra Nevada ◽  
Germ Line ◽  
Male Parent ◽  
Male Germ Line ◽  
Controlled Crosses

Some males of the grasshopper Chorthippus binotatus from a natural population in Sierra Nevada (Granada, Spain) were found to be polysomic mosaics for the presence of extra chromosomes (E) in a high proportion of testicular follicles. Transmission analysis of these chromosomes was performed in 21 controlled crosses, 2 of which involved a polysomic parent. While most spermatozoa produced by polysomic males carried E chromosomes, these chromosomes were not transmitted to the progeny, since all 22 embryos descended from a polysomic male parent lacked them.Key words: transmission, polysomy, grasshopper, Chorthippus binotatus.

scholarly journals The Imaginal Ecdysis of Blowflies. Detection of the Blood-Borne Darkening Factor and Determination of Some of Its properties

1962 ◽  
Vol 39 (3) ◽  
pp. 413-430
Author(s):  
C. B. COTTRELL
Keyword(s):  
Phenolic Compounds ◽  
Organic Solvents ◽  
Ethyl Alcohol ◽  
Room Temperature ◽  
Calliphora Erythrocephala ◽  
Bacterial Protease ◽  
Similar Factor ◽  
The Moment ◽  
Species Specific

1. At the imaginal ecdysis of Calliphora erythrocephala (Meigen) the initiation of normal hardening and darkening is brought about by the release into the blood of an active factor (Cottrell, 1962b). 2. The darkening factor can be detected in fly blood by injecting it into flies decapitated at the moment of emergence. Blood taken from flies at the moment of emergence or 24 hr. after expansion produces little or no reaction, although blood taken between 3 min. and 10 hr. after emergence shows darkening activity. However, extracts of other tissues and many chemicals will also induce darkening though probably unspecifically through damage effects. The assay can therefore be used certainly only for detecting activity in fly blood. 3. The blood-borne darkening factor of blowflies will withstand boiling for 10 min. or drying at 120° C. for 20 min., but it does not retain its activity when kept in solution at room temperature for more than 24 hr. It is non-dialysable, relatively insoluble in organic solvents and is inactivated by ethyl alcohol and the bacterial protease subtilisin. It is probably proteinaceous and is certainly not tyrosine or any of the phenolic compounds at present thought to act as the precursors of the tanning agent. 4. The blood-borne factor of different blowflies (Calliphora, Sarcophaga and Lucilia) is not species-specific and there is some inconclusive evidence that a similar factor is present at the ecdysis of Schistocerca.

Ideal diamagnetic response at room temperature by graphene-n-heptane-permalloy system

2020 ◽  
Vol 34 (36) ◽  
pp. 2050415
Author(s):  
Yasushi Kawashima ◽  
Rajendra Dulal ◽  
Serafim Teknowijoyo ◽  
Sara Chahid ◽  
Armen Gulian
Keyword(s):  
Magnetic Fields ◽  
Graphene Layer ◽  
Room Temperature ◽  
Condensed Matter ◽  
Condensed Matter Physics ◽  
Diamagnetic Response ◽  
Quantum Phenomenon ◽  
The Moment ◽  
Three Components

Perfect screening of sub-milligauss magnetic fields (ideal diamagnetism) by a system comprised of a graphene and thin permalloy foil parallel to the graphene layer immersed in [Formula: see text]-heptane is observed at room temperature. The presence of all three components is necessary for the effect to occur. Ideal diamagnetic response appears at the moment of [Formula: see text]-heptane injection and disappears when the liquid evaporates. Until then, no change of diamagnetic moment occurs at further variation of the field. The observed ideal diamagnetic feature is either a footprint of a novel type of superconductivity at room temperature or a yet unknown quantum phenomenon in condensed matter physics.

Research in the Plastics Division of Imperial Chemical Industries Limited

1956 ◽  
Vol 238 (1212) ◽  
Keyword(s):  
Chemical Industry ◽  
Room Temperature ◽  
Organic Chemical ◽  
Industrialized Countries ◽  
Technical Requirements ◽  
History Of ◽  
The Moment ◽  
Organic Chemical Industry ◽  
Future Growth ◽  
High Polymers

The Plastics Division of Imperial Chemical Industries Limited was formed in 1936 at a time when plastics, as then understood, were still a marginal activity of the organic chemical industry. The purpose of the Division was then, as it is to-day, to exploit commercially the chemical findings of the rest of the Company and those of the Division itself in the field of synthetic high polymers. In the Cantor Lectures in 1951 I outlined the history of the plastics industry (Swallow 1951); it is sufficient here to say that the technical requirements of the last war led to an enormous increase in the volume of the industry, so that to-day it is a major part of the chemical industry in all industrialized countries. For example, in the U. S. A., the growth is at the moment at the rate of 12½% per annum, which is greater than in any other section of industry in that country. Even so, official figures do not tell the story of the continuous diversification and improvement which have been among the main causes of this expansion, nor of the introduction of the new polymers which will provide the basis for future growth. Furthermore, the distinction between plastics and synthetic rubbers is now very difficult to make since both are high polymers, and whether a high polymer is a ‘plastic’ or a ‘rubber’ is determined largely by the fact that room temperature is around 300° K.

scholarly journals BROADENING THE GENETIC BASE OF CASSAVA, Manihot esculenta Crantz, BY INTERSPECIFIC HYBRIDIZATION

1989 ◽  
Vol 69 (3) ◽  
pp. 1071-1073 ◽  
Author(s):  
NAGIB M. A. NASSAR
Keyword(s):  
Interspecific Hybridization ◽  
Manihot Esculenta ◽  
Interspecific Hybrids ◽  
Marker Genes ◽  
Manihot Esculenta Crantz ◽  
Genetic Base ◽  
Controlled Crosses

Controlled crosses by vector insects resulted in the production of interspecific hybrids of cassava (Manihot esculenta Crantz) and Manihot species, while manual crosses failed. Marker genes for hairy stem, red disk, unribbed fruit, and foliaceous brackteoles proved efficient in recognizing interspecific hybridization between Manihot species and cassava.Key words: Wild cassava, Manihot neusana, Manihot anomala, interspecific hybridization, marker genes

scholarly journals Methodology of the tetrazolium test for identifying viable seeds of orchids of the genus Cattleya native to the Brazilian Cerrado

2021 ◽  
Vol 42 (3) ◽  
pp. 1351-1360
Author(s):  
Luan Marlon Ribeiro ◽  
◽  
José Carlos Sorgato ◽  
Jackeline Schultz Soares ◽  
Jéssica Celeste Mônico Ramos ◽  
...  
Keyword(s):  
Room Temperature ◽  
Germination Percentage ◽  
Seed Banks ◽  
Brazilian Cerrado ◽  
Randomized Design ◽  
Conditioning Temperature ◽  
Completely Randomized Design ◽  
Viable Seeds ◽  
Tetrazolium Test

Orchids need measures for conservation of their species, among them the creation of seed banks. This study analyzes suitable methodologies to identify the viability of Cattleya seeds through the tetrazolium test. Seeds of Cattleya nobilior Rchb. and Cattleya walkeriana Gardn. were submitted to three preconditioning: no soaking (control); sucrose (10%); or distilled water. After 24 hours, they were submitted to tetrazolium solution with three types of conditioning: oven (40 °C); water bath (40 °C); or room temperature. Subsequently, the percentage of viable seeds (VS) was calculated and in vitro sowing was carried out. Germination percentage (G) was determined after 45 days. A completely randomized design was used for each species studied, with treatments arranged in a 3x3 factorial scheme (three preconditioning and three conditioning), with eight replicates of one tube each. The experiment was performed in duplicate. The highest viability values found in the tetrazolium test were close to those of germination (C. nobilior: VS = 88% e G = 97%; C. walkeriana: VS = 88% e G = 95%) for Cattleya species native to the Cerrado. The conditioning at ambient temperature had a greater effect on seed visualization for both species studied, suggesting that the tetrazolium test should be performed at this conditioning temperature.

Room Temperature Formation of Ammonia by Oxidizing Hydrogenated Cerium Nanoparticles in the Air

2006 ◽  
Vol 6 (3) ◽  
pp. 813-817 ◽  
Author(s):  
Yaohua Zhang ◽  
Tong Liu ◽  
Zhong Wang ◽  
Yan Li ◽  
Xingguo Li
Keyword(s):  
Room Temperature ◽  
Hydrogen Plasma ◽  
Hydrogen Atoms ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Highly Active ◽  
The Moment ◽  
Favorable Conditions ◽  
Ammonia Formation ◽  
Chemical Force

Ammonia formation was observed when hydrogenated cerium nanoparticles prepared by hydrogen plasma-metal reaction (HPMR) were exposed to the air at room temperature. This novel phenomenon represents a successful example of room temperature cleavage of dinitrogen and may find application in low temperature synthesis of ammonia under thermodynamically favorable conditions. A possible mechanism is also proposed. We suggest that the oxidation of cerium hydride offers chemical force to drive the hydrogen atoms out of the lattice. The monoatomic H released to the surface is highly active and readily reacts with N2 to yield ammonia. Some surface processes, which we know little about at the moment, are likely to be involved so as to lower the energy barrier of nitrogen dissociation. Further investigation is required to elucidate the detailed mechanism.

scholarly journals Maturation of seeds of Poincianella pluviosa (Caesalpinoideae)

2015 ◽  
Vol 37 (2) ◽  
pp. 131-138 ◽  
Author(s):  
João Paulo Naldi Silva ◽  
Danilo da Cruz Centeno ◽  
Rita de Cássia Leone Figueiredo-Ribeiro ◽  
Claudio José Barbedo
Keyword(s):  
Room Temperature ◽  
Seed Viability ◽  
Dry Mass ◽  
Seed Vigor ◽  
Ex Situ ◽  
Environmental Constraints ◽  
Maturation Process ◽  
Short Lifespan ◽  
Wide Range ◽  
Viable Seeds

The persistence of viable seeds in the soil is an important way to assure plant propagation, especially for species which produce seeds with short lifespan. Poincianella pluviosa is a tree species which seeds have short to medium storability at room temperature. The comprehension of the maturation process is crucial to understand its strategy for propagation and it could provide tools to improve seed viability in ex situ conditions. Flowers were tagged in two consecutive cycles of maturation and pods were periodically harvested until dispersion. Seeds were classified based on their morpho-physiological features, capability to germinate and develop seedlings. The complete maturation process was attained 315-330 days after anthesis, a period longer than reported for seed viability at room temperature. The maximum dry mass and seed vigor were reached at the end of maturation, although elevated seedling production was obtained before physiological maturity. We suggest that the precocious ability to produce seedlings in a long maturation could be a strategy to overcome environmental constraints, as the species is distributed in a wide range of phytogeographic domains in Brazil.

scholarly journals Karakteristik produk dan efektivitas enkapsulasi bakteri pendegradasi asam sianida (HCN)

2018 ◽  
Vol 16 (2) ◽  
pp. 20
Author(s):  
A Mislah ◽  
S Suharti ◽  
I Wijayanti
Keyword(s):  
Manihot Esculenta ◽  
Room Temperature ◽  
Control Treatment ◽  
Rumen Bacteria ◽  
Product Characteristics ◽  
Bacterial Product ◽  
Cassava Leaves ◽  
Degrading Bacteria ◽  
Cyanide Degradation ◽  
Bitter Cassava

ABSTRAK<br /><br />Daun singkong pahit (Manihot esculenta)memiliki kandungan antinutrisi berupa asam sianida (HCN) yang tinggi, namun HCN dapat di degradasi dengan bakteri rumen. Penelitian ini bertujuan untuk mengamati karakteristik produk dan efektivitas enkapsulasi bakteri pendegradasi sianida dengan masa simpan (0, 1, 2, 3, 4, 5, 6, 7, 14, 21, 28 hari) pada suhu ruang. Peubah yang diamati adalah karakteristik produk dan viabilitas bakteri pendegradasi sianida terenkapsulasi. Data yang diperoleh dianalisa dengan sidik ragam (ANOVA) menggunakan program SPSS 16.0. Hasil penelitian menunjukkan bahwa lama penyimpanan berpengaruh terhadap perubahan warna dan bentuk dari produk hasil enkapsulasi. Penyimpanan produk enkapsulasi bakteri pendegradasi sianida selama 3 hari tidak mempengaruhiviabilitas bakteri dibandingkan kontrol. Namun demikian semakin lama penyimpanan produk enkapsulasi bakteri sampai hari ke 28 nyata menurunkan (P&lt;0.05) viabilitas bakteri.Hasil penelitian dapat disimpulkan bahwa dengan teknik enkapsulasi dapat mempertahankan viabilitas bakteri pendegradasi sianida.<br /><br />Kata kunci: bakteri pendegradasi sianida, karakteristik produk, penyimpanan,viabilitas<br /><br />ABSTRACT<br /><br />Bitter cassava leaves have high antinutrients in the form of cyanide acid (HCN), but HCN can be degraded with rumen bacteria. This research aimed to observe the product characteristics and the effectivity of cyanide degradation bacteria capsulation with different length of storages (0, 1, 2, 3, 4, 5, 6, 7, 14, 21, 28 days)in the room temperature. The observed variables were product characteristics and viability of cyanide degrading bacteriacapsulation. The data obtained were analyzed by Analysis of variance (ANOVA) using SPSS 16.0 program. The results showed that storages duration affected the color and shape of cyanide degradation bacteria capsulation products. The storage of capsulated HCN degrading bacteria up to 3 days did not affect the viability of bacteria compared to the control treatment. However, the longer storage of capsulated bacteria up to 28 days, significant decreased (P&lt;0.05) the viability of the bacteria. It is concluded that capsulation of cyanide degrading bacteria could maintain the viability of bacteria.<br /><br />Keywords: cyanide degradation bacterial, product characteristics, storage, viability

scholarly journals Assessment of the effect of long-term seed storage on the viability of Matricaria chamomilla seeds after cryopreservation

2021 ◽  
Vol 103 (3) ◽  
pp. 95-101
Author(s):  
Alibek Ramasanov ◽  
◽  
Larissa Babeshina ◽  
Keyword(s):  
Seed Germination ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Germination Rate ◽  
Seed Storage ◽  
Water Bath ◽  
Moscow Region ◽  
Matricaria Chamomilla ◽  
Test Species ◽  
Viable Seeds

The article presents the study of influences of cryopreservation on seed germination of Matricaria chamomilla. Four varieties «Moscow Region», «Karagandinskaya», «Aibolit» and «Old Lekar» are used in the work. The seeds of the test species are cryopreserved in liquid nitrogen, followed by defrosting at room temperature and rapid defrosting in a water bath at temperature +40 Ԩ. After cryopreservation the seeds are planted in Petri dishes and placed in a climate chamber for determination laboratory germination. It is noted that the best results are obtained in the defrosting variant at the room temperature. So the maximum germination rate for variety «Karagandinskaya» was 84.0 %, energy of germination — 83.0 %; for «Aibolit» variety was 82.0 % and 81.0 %, respectively; «Moscow Region» variety had a minimum germination rate — 13.0 % and energy of germination 10.0 %. While for the «Old Lekar» variety, the optimal thawing mode was rapid thawing in a water bath at the temperature +40Ԩ; seed germination was 63.0 %, energy of germination — 62.0 %. Thus, it is necessary for receiving more viable seeds of varieties of Matricaria chamomilla after freezing in liquid nitrogen to apply the slow mode of thawing at the room temperature +24 Ԩ.

Sign in / Sign up

Export Citation Format

Share Document