THE EFFECT OF THE GAMMA-ISOMER OF BENZENE HEXACHLORIDE UPON THE MICROFLORA OF SUBMERGED RICE SOILS: I. EFFECT UPON ALGAE

1967 ◽  
Vol 13 (2) ◽  
pp. 173-180 ◽  
Author(s):  
K. Raghu ◽  
I. C. MacRae
Keyword(s):  
Green Algae ◽  
Detrimental Effect ◽  
Stem Borer ◽  
Rice Soils ◽  
Blue Green Algae ◽  
Rice Stem Borer ◽  
Submerged Soils ◽  
Algal Groups ◽  
Benzene Hexachloride ◽  
Qualitative Changes

The effect of additions of the gamma-isomer of benzene hexachloride (gamma-BHC) upon algal populations in two submerged tropical rice soils was studied. Additions of the insecticide to the floodwaters of the soils at 5, 6, and 50 kg/ha active compound resulted in a marked stimulation of growth of the indigenous algae. The stimulation was attributed to the elimination by the insecticide of small animals which feed on the algae. No detrimental effect upon total algal populations was found when gamma-BHC was applied at 50 kg/ha, which is 10 times the rate recommended to control the rice stem borer. Qualitative changes were detected in the incidence of major algal groups. Blue-green algae were more abundant in treated soils whereas the green algae and diatoms were more abundant in the untreated soils. Much larger amounts of algal tissue were produced in the floodwaters treated with gamma-BHC. The possible effects of increased algal development on the fertility of the soil and the persistence of gamma-BHC in submerged soils are discussed.

Nitrogen-fixing Blue-Green Algæ in Australian Rice Soils

Nature ◽  
1961 ◽  
Vol 192 (4801) ◽  
pp. 479-480 ◽  
Author(s):  
J. S. BUNT
Keyword(s):  
Green Algae ◽  
Nitrogen Fixing ◽  
Rice Soils ◽  
Blue Green Algae

Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

1967 ◽  
Vol 25 ◽  
pp. 74-75
Author(s):  
L. V. Leak
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Green Algae ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Photosynthetic Membranes ◽  
Blue Green Algae ◽  
Cell Biol ◽  
Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

Electron microscope study of the effects of radiation on insect fertility

1990 ◽  
Vol 48 (3) ◽  
pp. 72-73
Author(s):  
Judy Ju-Hu Chiang ◽  
Robert Kuo-Cheng Chen
Keyword(s):  
Electron Microscopy ◽  
Germ Cell ◽  
Germ Cells ◽  
Electron Microscope Study ◽  
Radiation Treatment ◽  
Light And Electron Microscopy ◽  
Stem Borer ◽  
Metabolic Energy ◽  
Rice Stem Borer ◽  
Effects Of Radiation

Germ cells from the rice stem borer Chilo suppresalis, were examined by light and electron microscopy. Damages to organelles within the germ cells were observed. The mitochondria, which provide the cell with metabolic energy, were seen to disintegrate within the germ cell. Lysosomes within the germ cell were also seen to disintegrate. The subsequent release of hydrolytic enzymesmay be responsible for the destruction of organelles within the germ cell. Insect spermatozoa were seen to lose the ability to move because of radiation treatment. Damage to the centrioles, one of which is in contact with the tail, may be involved in causing sperm immobility.

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