Azolla Imbricata Research Articles

Development and survival of anopheline immatures (Diptera: Culicidae) in rice fields in northern Thailand.

Development and survival of immature anopheline mosquitoes were studied in 4 rice fields in northern Thailand. Adding food to rice-field water shortened the larval duration and increased pupal size of Anopheles peditaeniatus in predatorfree cages. The mean survival of natural populations of Anopheles (Anopheles) (mostly peditaeniatus and sinensis ) from larval hatch to adult emergence was estimated to be 2% (range 0–6%) using vertical age-grading methods. Mortality attributable to aquatic predators was variable among fields (19–54%) and was correlated positively with the abundance of aquatic predators (excluding Cyclopoida). Surface predators were a minor mortality factor (0–10%). Nonpredator-related mortality was greater than predator-related mortality in 2 of 4 rice fields. The floating plant Azolla imbricata increased mortality among An. peditaeniatus and An. sinensis larvae in the laboratory.

Electron Microscope Observations on the Leaf of Azolla imbricata Nakai

In the electron micrographs of the leaf in Azolla imbricata, the following could be observed.1. In the young cell wall, plasmodesmata are well observed.2. In the leaf cells, Golgi apparatus and endoplasmic reticulum not so many are observed as in cells of roots or root hairs.3. Immature plastids in the leaf cells show similar structures to those observed in root cells or the root hair ones, while mature plastids show well differentiated grana-lamellae similar to the plastid common in higher plants.4. It is concluded that the plastids found in Azolla roots or root hairs have an ability to change to chloroplasts.

Electron Microscope Observations on the Root Hair Cell of <i>Azolla imbricata</i> Nakai

1. In the electron micrographs of root hair cells of Azolla imbricata, the following intracellular organellae were observed.2. In the vacuoles, a number of heavily electron-dense bodies are seen. They appear to be aggregates of particles of ca. 30mμ in diameter and probably of lipid nature.3. The mitochondria show features of the typical structure of those described in plant cells.4. The plastids in cells treated with osmium fixatives appear to be composed of lamellae and grana-like structures. The plastids in cells fixed with permanganate show the piles of several short lamellar structures, i.e., grana-like structures, but show no so-called lamellar structures.5. The endoplasmic reticulum is seen irregularly winding in a shape of discrete layers or in stacks of lamellar layers. Palade granule-like bodies are seen in osmium-fixed cells, but not demonstrated in permanganate-fixed cells.6. The Golgi-like structures are composed of cisternae, and small discrete vesicles are often found at the edges of the cisternae, which appear more clearly in permanganate-fixed cells than in osmium-fixed ones.