Screening of kenaf (Hibiscus cannabinus L.) genotypes for low temperature requirements during germination and evaluation of feasibility of seed production in Italy

1998 ◽  
Vol 59 (1) ◽  
pp. 73-79 ◽  
Author(s):  
L.G Angelini ◽  
M Macchia ◽  
L Ceccarini ◽  
E Bonari
Keyword(s):  
Low Temperature ◽  
Seed Production ◽  
Hibiscus Cannabinus ◽  
Temperature Requirements

scholarly journals Effects of season, altitude and daylength on floral initiation of two contrasting genotypes of Trifolium repens L.

1986 ◽  
Vol 106 (1) ◽  
pp. 149-154 ◽  
Author(s):  
F. Von Sury ◽  
J. Nösberger
Keyword(s):  
Low Temperature ◽  
Seed Production ◽  
Floral Initiation ◽  
Cool Season ◽  
Production Potential ◽  
Low Latitude ◽  
Specific Effects ◽  
Trifolium Repens L ◽  
Growth Chambers ◽  
Main Factors

SUMMARYThe effects of season and altitude on floral initiation of two Trifolium repena L. cultivars, Haifa and California Ladino, were tested in the area of Ayacucho, Peru (2730 m, 13° S), with regard to their seed production potential. Specific effects of daylength at a constant temperature (20 °C) were examined in growth chambers.In Ayacucho, the proportion of inflorescence-bearing nodes was found to be lowest between December and June (Haifa 10–20%, Ladino 0–10%) and highest in August (Haifa 30%) and September–October (Ladino 15%). Late in the cool season, floral initiation of Ladino, but not that of Haifa, increased strongly at a high altitude (3250 m). In growth chambers, Haifa initiated few inflorescences and Ladino none in a 10 h daylength. In 16 h, the floral initiation of Haifa was very limited but Ladino formed many inflorescences. Floral initiation of Haifa was most pronounced and lasted longest after a daylength shift from 10 to 13 h.It is concluded that seasonal and altitudinal variations in low temperature were the main factors influencing floral initiation in the region of Ayacucho. Haifa is considered to be an intermediate-day plant, suited for seed production in the region because of its marked and early flowering. Ladino was classified as a quantitative longday plant, unsuitable for seed production at this low latitude because of its retarded floral response to low temperature.

Flower initiation in pasture legumes. II. Geographical implications of cold temperature requirements of varieties of Trifolium subterraneum L.

1955 ◽  
Vol 6 (2) ◽  
pp. 245 ◽  
Author(s):  
Y Aitken
Keyword(s):  
Low Temperature ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Flower Initiation ◽  
Summer Drought ◽  
Productive Capacity ◽  
Northern Australia ◽  
Mild Winter ◽  
Temperature Requirement ◽  
Temperature Requirements

In Trifolium subterraneum L. (subterranean clover) the low temperature requirements of its range of varieties, together with the mild winter of southern Australia, result in a lengthened growing season compared with that usual in northern Europe, and hence in greater productivity. Over much of southern Australia, some degree of summer drought prevents the use or reduces the yield of perennial species and so the productive capacity of this particular clover has made it of major importance in pastures. The low temperature requirement, however, reduces the value of the species as a self-regenerating annual where temperatures of both summer and winter seasons are too high for flower initiation. This occurs with the later varieties when sown in northern Australia. Temperatures of the summer growing season in the tropics are likely to be too high even for the short low temperature requirement of the earliest flowering group, with its high critical upper margin of about 75°F mean weekly temperature. The dry winter months are cooler, and, if water supply is available, flower initiation is possible, though retarded with consequent leafiness of the plant. Hence in northern Australia, only varieties in the early flowering group may be of use in pastures, and then only in the cooler parts of the region.

scholarly journals Survival of Clinical and Poultry-Derived Isolates of Campylobacter jejuni at a Low Temperature (4°C)

2001 ◽  
Vol 67 (9) ◽  
pp. 4186-4191 ◽  
Author(s):  
Kam Fai Chan ◽  
Huyen Le Tran ◽  
R. Y. Kanenaka ◽  
S. Kathariou
Keyword(s):  
Low Temperature ◽  
Campylobacter Jejuni ◽  
Cold Exposure ◽  
Low Temperatures ◽  
Prolonged Exposure ◽  
Dependent Manner ◽  
Temperature Requirements ◽  
Bacterial Gastroenteritis ◽  
Different Strains ◽  
Strain Dependent

ABSTRACT Campylobacter jejuni is a leading cause of bacterial gastroenteritis in humans, and contamination of poultry has been implicated in illness. The bacteria are fastidious in terms of their temperature requirements, being unable to grow below ca. 31°C, but have been found to be physiologically active at lower temperatures and to tolerate exposure to low temperatures in a strain-dependent manner. In this study, 19 field isolates of C. jejuni (10 of clinical and 9 of poultry origin) were studied for their ability to tolerate prolonged exposure to low temperature (4°C). Although substantial variability was found among different strains, clinical isolates tended to be significantly more likely to remain viable following cold exposure than poultry-derived strains. In contrast, the relative degree of tolerance of the bacteria to freezing at −20°C and freeze-thawing was strain specific but independent of strain source (poultry versus clinical) and degree of cold (4°C) tolerance.

scholarly journals Low-Temperature Requirements for Bitumen in Central East European Road Construction

2019 ◽  
Vol 14 (2) ◽  
pp. 249-270 ◽  
Author(s):  
Piotr Radziszewski ◽  
Michał Sarnowski ◽  
Jan Król ◽  
Piotr Pokorski ◽  
Piotr Jaskuła ◽  
...  
Keyword(s):  
Low Temperature ◽  
Eastern Europe ◽  
Low Temperatures ◽  
Central And Eastern Europe ◽  
Asphalt Pavements ◽  
Modified Bitumen ◽  
Performance Grade ◽  
Temperature Requirements ◽  
On The Road ◽  
Special Assessment

The paper presents the proposition of special assessment of low temperature requirements for bitumens in the region of Central and Eastern Europe where there is a moderate transitional area from sea to the continental type of climate. The results of the research program conducted on the road neat bitumens, Styrene-Butadiene-Styrene polymer and polymer-rubber modified bitumen, and multigrade bitumen types were presented and discussed. Based on the Superior Performing Asphalt Pavements Performance Grade procedure for low temperatures, climatic zones in Poland were developed and compared to analogous zones for other countries from the Central and Eastern Europe region as Estonia and Belarus. The results of functional Performance Grade tests and European standard test of bituminous binders were analysed. It was concluded that some of the bitumens were not meet the performance requirements in the range of low temperatures by Superior Performing Asphalt Pavements Superpave specification and the low-temperature properties of those bitumens should be improved.

Low Temperature Plasma Sintering of Silver Nanoparticles for Potential Flexible Electronics Applications

2012 ◽  
Vol 1529 ◽  
Author(s):  
Siyuan Ma ◽  
Vadim Bromberg ◽  
Frank D. Egitto ◽  
Timothy J. Singler
Keyword(s):  
Low Temperature ◽  
Flexible Electronics ◽  
Treatment Time ◽  
Functional Materials ◽  
Average Diameter ◽  
Plasma Parameters ◽  
Temperature Plasma ◽  
Polymer Substrates ◽  
Flexible Polymer ◽  
Temperature Requirements

ABSTRACTDeposition of solution-processed functional materials generally requires additional post-processing to optimize the functionality of the material. We study sintering of Ag nanoparticle (NP) (with average diameter 77nm) deposits for improved electrical conductivity, with emphasis on Argon plasma methods compatible with the low temperature requirements of regular low-cost flexible polymer substrates. The relationship between plasma parameters (such as power and treatment time) versus sintering results (sintered structure depth, film continuity and electrical sheet resistance) will be reported. According to our efforts so far, we have achieved the electrical resistivity of the sintered film at about 20 times greater than the value of bulk silver using a process compatible with the low temperature requirements of common flexible polymer substrates.

scholarly journals Characteristics of Fertility Transition Response to the Cumulative Effective Low Temperature in a Two-Line Male Sterile Rice Cultivar

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Linxuan Wu ◽  
Huazhen Rong ◽  
Chun Chen ◽  
Xin Lin ◽  
Jiafeng Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Seed Production ◽  
Pollen Fertility ◽  
Hybrid Rice ◽  
Fertility Transition ◽  
Day Length ◽  
Sensitive Period ◽  
Rice Seed ◽  
Night Temperature ◽  
Male Sterile

Abstract Background Photo-thermo-sensitive genic male sterile (PTGMS) rice (Oryza sativa L.) is usually considered two-line male sterile rice because of its dual-purpose in two-line hybrid rice system: under short days and low temperatures, it is fertile and used for self-propagation, but under long days and high temperatures, it is sterile and used for hybrid seed production. Therefore, photoperiod and temperature conditions are extremely important for the fertility transition of two-line male sterile rice. In recent years, there have been frequent occurrences of abnormally low-temperature (ALT) resulting in failure of two-line hybrid rice seed production. The daily average temperature (DAT) during ALT events is sometimes higher than the critical sterility-inducing temperature (CSIT) of two-line male sterile rice, of which the night temperature is lower than the CSIT. DAT has been traditionally used as the single indicator of pollen fertility transition, but it is unknown why the fertility of two-line male sterile rice in seed production restored fertility under ALT conditions. Results For Hang93S (H93S), a newly released PTGMS line, we hypothesized fertility transition is determined mainly by the cumulative effective low temperature (ELT) and only a certain duration of low temperature is required every day during the fertility-sensitive period. This study simulated ALTs where the DAT was higher than the CSIT while some segments of night temperature were lower than the CSIT. The results showed H93S exhibited a fertility transition to varying degrees. Moreover, fertility was restored under simulated ALT conditions and pollen fertility increased with increasing cumulative ELT, indicating that the fertility transition was affected primarily by the cumulative ELT. Results also indicated that pollen fertility increased as the number of treatment days increased. Conclusions The fertility transition is caused mainly by the cumulative ELT. In two-line male sterile rice breeding, the effects of day length, ALT at night, and continuous response days should be considered together. The present study provides new insight into fertility transition so breeders can more effectively utilize the two-line male sterile rice, H93S, in breeding programs.

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