Porphyra is a kind of marine red algae. The thallus is composed of a layer of cells embedded in a thin layer of colloid, which is dark brown, red or purple. The sexual reproductive structure is at the edge of the thallus. It is distributed in the northern and southern hemispheres, grows at the high tide line of intertidal zone, and grows best in nitrogen-rich waters (such as near the outlet of sewage pipes). After harvesting and drying, it can be used as food, and its consumption exceeds that of other seaweeds. Artificial farming is an important food in eastern countries. It can be used as the main ingredient of soup and the seasoning of other foods and meat. In the British Isles, laver is baked on bread and tastes like oysters.
As early as 1400 years ago, Yao Min's Book of the Northern Wei and Qi Dynasties in China mentioned that "all of them are in the seaside mountains of Wudu, and they know how to eat laver". According to Meng E's Herbal Medicine for Dietotherapy in the Tang Dynasty, laver was "born in the South China Sea, blue in color, with stones attached and dried purple". During the Northern Song Dynasty, laver has become a precious tribute. In the book Compendium of Materia Medica in Ming Dynasty, Li Shizhen not only described the morphology and collection method of laver, but also pointed out that laver was mainly used for "hot air disturbing the throat" and "scabies and lumps, so it is appropriate to eat laver often". It can be seen that laver has a long history in China. Japanese fishermen may have collected natural seedlings with bamboo branches and branches in the first half of the17th century, and then cultivated them with bamboo curtains and natural fiber cross-net curtains. For a long time, laver seedlings can only rely on natural growth, with limited sources and small-scale breeding activities. 1949, K.M. Drew of Britain discovered for the first time that the important fruiting spore growth period of laver was spent in shells, which opened the way for studying the source of natural seedlings. Then in 1953 and 1955, China Zeng Chengkui revealed the whole life history of laver, which laid a theoretical foundation for artificial breeding. Since then, laver culture has entered the period of full artificial production, and the output has been greatly improved.
Porphyra is simple in shape and consists of three parts: a disc-shaped fixer, a handle and a blade. Leaves are single or branched membranous bodies composed of 1 layer cells (a few species have 2 or 3 layers), and their length varies from several centimeters to several meters according to different species. Contains chlorophyll, carotene, lutein, phycoerythrin, phycocyanin and other pigments. Different kinds of laver show purple, blue-green, reddish brown, green brown and other colors because of their different content ratios, but most of them are purple, so they are named laver.
The life of laver includes two distinct stages: the larger thallus (gametophyte generation) and the smaller filamentous body (sporophyte generation). The thallus is sexually propagated, and the vegetative cells are transformed into female and male cells respectively. After fertilization, female cells divide many times to form fruit spores, which are released from algae in seawater when they mature, and attach to calcareous shells and other substrates with the flow of seawater, germinate and grow into filaments. When the filamentous body grows to a certain extent, it will produce cyst branches of the shell spores, and then divide to form the shell spores. After release, the shell spores attach to rocks or artificial stakes or net curtains and germinate directly into phyllodes. In addition, some kinds of bacteria can also reproduce asexually, from vegetative cells to monospores, and grow directly into bacteria after spreading and attaching. Monospore is also one of the important seed sources in aquaculture production.
Porphyra thallus mostly grows in intertidal zone, and likes the sea area with strong wind and waves, gentle tidal current and rich nutrition. Strong tolerance; The suitable light intensity is 5000 ~ 6000 lux, which has the characteristics of high light saturation point and low light compensation point and belongs to high-yield crops. The adaptability to low temperature varies with the water content of algae. When it is quickly dried to a water content of 20%, it can still recover its vitality at a low temperature of about -20℃ for several months to 1 year. It has a wide range of application to the specific gravity of seawater, but 1.020 ~ 1.025 is suitable. Filaments have poor dry resistance and low requirements for light, and are naturally distributed below the low tide line. Under the condition that the temperature begins to drop and the sea water flows, conchospores are often released in large quantities at 9 ~ 1 1 every morning, showing obvious diurnal periodicity.
Polysiphonophora is the most common algae in seawater, belonging to ceramium order of Euphyridia. Plants are filaments with rows of branched cells. There are 1 row cells in the center of filament, which is called axial tube, and there are marginal cells produced by axial tube around it, which is called periaxial tube. Some kinds of filaments are divided into upright filaments and creeping filaments, and the base is fixed on the seaside rock with a single cell rhizome, which is about 3 ~ 20 cm high. Polysaccharide plants have haploid female and male gametophytes, diploid fruit sporophytes and tetrasporophytes. The gametophyte and tetraspore have the same shape, which is a typical isomorphic generation alternation. Sperm cysts are born on the reproductive branches above the male gametophyte and fruit cysts are born on the reproductive hairs above the female gametophyte. When fruiting bodies are produced, there are 1 special pericytes (also called supporting cells) beside the axial cells of hair, thus producing 4-cell fruiting bodies. The top cell of the fruiting body is a fruit cell with fertilized filaments, and the fruit nucleus divides into 2, the lower nucleus is the fruit nucleus, and the upper nucleus is the fertilized filament nucleus. Later, this nucleus degenerated. Sperm enters the fruit cell from the fertilized egg silk and combines with the egg. At the same time, supporting cells produce several cells, which are called helper cells. Fruit cells are connected with supporting cells through auxiliary cells below them. The zygote nucleus divides into two, enters the supporting cell, and continues to divide in this cell, and the rest nuclei degenerate. At this time, many sporogenous filaments appear in the supporting cells, and the nuclei in the supporting cells move towards the sporogenous filaments. Fruit sporangium is formed at the end of sporogenous filament, and there are two nuclei in each sporangium. At the same time, supporting cells fuse with surrounding cells to form sporangium, which is called ascospores (fruit sporophytes). Fruit spores germinate to form diploid tetrasporophytes. Four sporophytes are formed on the four sporophytes, and after meiosis, four haploid spores are formed, which germinate to form male and female gametophytes.
Carrageenan is an important economic seaweed in China, belonging to Rhodophyta, Taxodiaceae and Carrageenan. Carrageenan is not only an important protoalgae for producing carrageenan, but also more and more used in the medical field in recent years, which has attracted widespread attention.
From ~ 65438 to 0992, through the investigation and study of Liaodong Peninsula, it was determined that only one carrageenan was widely distributed. The morphology and size of this algae vary greatly and can be divided into four different forms. Among them, the original form of carrageenan was first discovered in China.
Carrageenan is reddish purple, cartilaginous and tough. It is tufted, 5 ~ 12 cm high, cylindrical at the base, gradually flattened upward into a wedge shape, and the upper branches bifurcate for 2 ~ 7 times, and the leaf axils are wide, round, fan-shaped, flat, tongue-shaped or slightly concave at the top, blunt, slightly thick at the edge, or with single bifurcation, wedge-shaped, tongue-shaped, short or long branches. The pith consists of many long algae filaments arranged vertically parallel to the epidermis. Tetrasporangium scattered on both sides of the upper part of the branch, showing irregular spots. The mature capsule is oval and protrudes from one side of the algae body; The other side is concave. Fixator shell-shaped.
Gelidium, also known as frozen vegetables, red silk and phoenix tail, is a kind of red algae. It is transparent, like jelly, crisp and tender, and can be mixed with cold dishes to make jelly. Gelidium is also the main raw material for extracting agar. Agar, also known as watercress, starch and gelatin, is an important plant gum, which belongs to fiber food and can be dissolved in hot water. Agar can be used to make cold food, jelly or microbial culture medium.
There are two main ways to reproduce cauliflower: sexual reproduction and asexual reproduction. Sexual reproduction is carried out through male and female gametes. Asexual reproduction is carried out by four spores produced by four spores. These two forms of reproduction are ultimately carried out by spores, so they are called spore reproduction. In addition, cauliflower also has special vegetative reproduction ability, which can be divided into three forms: creeping reproduction, rhizome reproduction and algae regeneration.
In the life history of cauliflower, there are sporophyte generation, gametophyte generation and fruit sporophyte generation. However, fruit sporophyte can not exist alone, but can only form and grow on female sporophyte. In the non-breeding season, the four sporophytes of male and female gametophytes are difficult to distinguish. We usually see these three kinds of algae, only in the breeding season. After the reproductive organs are produced on algae, they can be distinguished.
Chondrophyta grows on rocks near the low tide line. Produced in Cape, Holy Mountain, Putuo Mountain, Zhongjie Mountain, Yushan Mountain, Dongtou and Nanji. It is distributed along the coast of China.
Dark green to reddish brown with fleshy cartilage, 8 ~ 15cm high and 2 ~ 4mm wide. The main branches are oblate cylindrical, irregularly branched in all directions, with contracted bases and bulbous buds at the top. After shedding, it can develop into a new individual and the capsule is born on the branch.
Hedgerow plants are red, dark purple-green or dark brown-red, and their bones are soft or thick and juicy and easy to break. The height is 5 ~ 45 cm, some of which can reach 1 m, and the base is provided with a disc-shaped fixer. Erect and clustered, fleshy, cylindrical, with obvious trunk, 1 ~ 2 branches, alternate or unilateral, and pods protruding from the surface. Branches alternate, oblique or irregular, and plants are uniaxial. There is an apical cell at the top, which divides horizontally into secondary cells and then continues to divide into medullary cells and cortical cells.
Gracilaria likes to grow in the bay with fresh water inflow and fertile water quality, especially in the harbor with calm wind and waves, smooth water flow, flat terrain and clear water quality, which is distributed in Qingdao, China. The calm inner bay can be used to make food and glue.
Luo Hai Luo Hai is a genus of Rhodophyta. The plants are erect, the branches are irregularly forked, cylindrical or flat, and the internal tissues are loose or hollow; Tetrasporangium is scattered in the cortex and divided in a cross shape; The capsule is spherical or hemispherical, protruding from the body surface and densely distributed on algae. There are 7 species of this genus, all of which are marine products, distributed in temperate waters along the coast of the North Pacific Ocean or slightly extending in the north-south direction. Two domestic species: sea rose, purple, 4 ~ 10 cm high, up to 15 cm, born on rocks in high and middle intertidal zones and produced in coastal areas; The outer shape of antlers is similar to that of sea otters, but its branches are tapered, and the last branches are often antlers. It was born on rocks in the middle and low tide zone and found in the East China Sea of China and the mainland coast of Guangdong Province. Sea otters and sea otters contain a lot of gum, so they have strong drought resistance and are often clustered, which can be used as food and medicine. Bohai gum can also be used in printing and dyeing industry.
Eucheuma eucheuma or eucheuma eucheuma, commonly known as coral grass, seaweed and benthic algae red algae, is brightly colored, such as green, brown, beige, purple and red. There are more than 2,500 species of red algae, most of which are now called coral grass, such as carrageenan and eucheuma, which belong to the marine red algae. It is about 20 cm high and its shape is quite similar to that of coral, so most people call it by its shape. Carrageenan and Eucheuma are extremely rich in nutrition and have the effect of "cleaning first and then supplementing", so they are called "coral grass" together with Japanese thick shore grass. Japanese thick shore grass, also known as salt grass, sacred grass and blessed grass, has been regarded as the secret of longevity since ancient times. In the Zhou Dynasty, the Japanese presented salt grass as a precious tribute to Emperor China. Its shape is quite close to that of coral grass on the market today, but thick shore grass only grows in Kendo Lake, Saloma Lake and Oyster Island in Houan Bay, Hokkaido, Japan, and its output is extremely rare. It has long been listed as a valuable national resource by the Japanese government, and it is simply not available in the market. Now even the so-called "coral grass" sold in Japan's domestic market is imported from Japan, such as red algae carrageenan and eucheuma, which shows that red algae carrageenan and eucheuma are very valuable edible plants.
Compared with kelp, Undaria pinnatifida, laver and other marine plants, Eucheuma is mainly composed of polysaccharide, cellulose and minerals, but the content of protein and fat is very low. Judging from the protein and fat content, the nutritional value of Eucheuma is extremely low. But if we look at it from another angle, Eucheuma is a rare high-quality health food. Eucheuma is a kind of food with high dietary fiber, because it is rich in polysaccharide and fiber rope. Dietary fiber is an essential substance for human body, which has the functions of preventing and treating gastric ulcer, anticoagulation, reducing blood lipid and promoting collagen growth. And eating high dietary fiber food is easy to produce satiety, which has a certain effect on losing weight. At the same time, Eucheuma is also rich in minerals, especially calcium and zinc. Its calcium content is 5.5 times that of kelp, 3.7 times that of Undaria pinnatifida and 9.3 times that of laver. The zinc content is 3.5 times that of kelp, 6 times that of Undaria pinnatifida and 1.5 times that of laver. Calcium plays an important role in maintaining the normal physiological functions of human circulation, respiration, nerves, digestion, endocrine, bones, urine and immune system. Zinc is an important trace element necessary for human body. About 80 enzymes and 14 activators are related to zinc. Zinc deficiency can cause a series of metabolic disorders, abnormal physiological functions, growth and intellectual development disorders.