Ecophysiological studies on Spirulina platensis Effect of temperature, light intensity and nitrate concentration on growth and ultrastructure

1980 ◽  
Vol 46 (2) ◽  
pp. 113-127 ◽  
Author(s):  
C. van Eykelenburg
Keyword(s):  
Light Intensity ◽  
Spirulina Platensis ◽  
Nitrate Concentration ◽  
Effect Of Temperature

Seed germination ecology of Sumatran fleabane (Conyza sumatrensis) in relations to various environmental parameters

Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Gulshan Mahajan ◽  
Asheneel Prasad ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Seed Germination ◽  
Light Intensity ◽  
Chloride Concentration ◽  
Soil Surface ◽  
Control Treatment ◽  
Effect Of Temperature ◽  
Burial Depth ◽  
Germination Ecology ◽  
Wide Range ◽  
Dark Conditions

Abstract Sumatran fleabane [Conyza sumatrensis (Retz.) Walker] is an emerging weed in the Australian cropping region. Populations resistant to glyphosate have evolved in Australia, creating the demand for information regarding the seed germination ecology of glyphosate-resistant (R) and glyphosate susceptible (S) populations of C. sumatrensis. A study was conducted to examine the effect of temperature, light intensity, salt stress, osmotic stress, and burial depth on the germination and emergence of two populations (R and S) of C. sumatrensis. Both populations were able to germinate over a wide range of alternating day/night temperatures (15/5 to 35/25 C). In light/dark conditions, the R population had higher germination than the S population at 20/10 and 35/25 C. In the dark, the R population had higher germination than the S population at 25/15 C. In the dark, germination was inhibited at 30/20 C and above. Averaged over populations, seed germination of C. sumatrensis was reduced by 97% at zero light intensity (completely dark conditions) compared with full light intensity. Seed germination of C. sumatrensis reduced by 17 and 85% at an osmotic potential of −0.4, and −0.8 MPa, respectively, compared with the control treatment. The R population had lower germination (57%) than the S population (72%) at a sodium chloride concentration of 80 mM. Seed germination was highest on the soil surface and emergence was reduced by 87 and 90% at burial depths of 0.5 and 1.0 cm, respectively. Knowledge gained from this study suggests that a shallow-tillage operation to bury weed seeds in conventional tillage systems, and retention of high residue cover in a zero-till system on the soil surface may inhibit the germination of C. sumatrensis. This study also warrants that the R population may have a greater risk of invasion over a greater part of a year due to germination over a broader temperature range.

The tillering pattern in barley varieties: II. The effect of temperature, light intensity and daylength on the frequency of occurrence of the coleoptile node and second tillers in barley

1969 ◽  
Vol 72 (3) ◽  
pp. 423-435 ◽  
Author(s):  
R. Q. Cannell
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Light Intensity ◽  
Field Experiments ◽  
Tiller Number ◽  
Effect Of Temperature ◽  
Controlled Environment ◽  
Frequency Of Occurrence ◽  
Low Light ◽  
Late Sowing

SUMMARYControlled-environment experiments showed that development of the coleoptile node tiller (T1) was suppressed much more than that of the tiller appearing in the axil of the first true leaf (T2) by high temperature (24/15 °C; 19/10 °C; 10/6 °C), by reduced photoperiod (16 h; 12·5 h) or by low light intensity (1100 ft-c; 1000 ft-c), but minimally in the newest variety, Deba Abed. Unlike previous field experiments, the T1 tiller appeared on more Spratt Archer than Maris Badger plants. Maris Badger plants produced more T1 tillers in a high-low temperature regime (19/10 °C; 10/6 °C) than in continuous low temperature (10/6 °C). In a field experiment T1 tiller number (and yield), but not the number of other major shoots, were severely reduced by late sowing of Spratt Archer, progressively reduced in Maris Badger, but minimally in Deba Abed. This seemed to be associated with higher temperatures at later sowings.

Effects of biomass weight and light intensity on the performance of photosynthetic microbial fuel cells with Spirulina platensis

2009 ◽  
Vol 100 (18) ◽  
pp. 4183-4186 ◽  
Author(s):  
Chun-Chong Fu ◽  
Chia-Hung Su ◽  
Tien-Chieh Hung ◽  
Chih-Hung Hsieh ◽  
Devi Suryani ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Light Intensity ◽  
Microbial Fuel Cells ◽  
Spirulina Platensis

scholarly journals Pengaruh Suhu Terhadap Siklus Hidup Lalat Buah (Drosophila melanogaster)

2019 ◽  
Vol 5 (2) ◽  
pp. 114-120
Author(s):  
Suharsono Suharsono ◽  
Egi Nuryadin
Keyword(s):  
Drosophila Melanogaster ◽  
Life Cycle ◽  
Quantitative Analysis ◽  
Light Intensity ◽  
Block Design ◽  
Fruit Flies ◽  
Effect Of Temperature ◽  
Fast Time ◽  
Randomized Block Design ◽  
Time Required

Fruit flies (Drosophila melanogaster) generally have four phases in their life cycle, namely eggs, larvae, pupae and imago. In general, Drosophila melanogaster experiences a life cycle of 8-11 days at optimal temperatures. At lower temperatures the time required to complete its life cycle is relatively longer and slower which is around 18-20 days. Whereas at higher temperatures adult flies that grow will be sterile. The development period of Drosophila melanogaster in its life cycle is influenced by several factors, namely ambient temperature, food availability, level of maintenance density and light intensity. This study aims to determine the effect of temperature on the life cycle of fruit flies (Drosophila melanogaster). The study will be analyzed using quantitative analysis using randomized block design (RBD) with six temperature difference treatments for each treatment and repeated 4 times so that there are 24 experiments. The results showed the development in the Drosophila melanogaster cycle starting from Egg - Larva (Instar I) - Larva (Instar II) - Larva (Instar III) - Pre Pupa - Pupa - Imago. The life cycle of Drosophila melanogaster has an average of 42.08 hours or 1.75 days up to 79.96 hours or 3.33 days in each treatment. And obtained a fast time during the life cycle of Drosophila melanogaster at a temperature of 30°C is 10.47 days and the longest at a temperature of 18°C is 18.35 days.

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