One of the factors that influence the success in the cultivation of seaweed are seedlings. Seeds for plants that function to reproduce or breed tanaman.umur thallus. Seed should be used in the form of cuttings, to be healthy, young and many branches. Seedlings obtained is the end of the crop (young) generally provide good growth and harvests containing carrageenan which is higher than the seedlings from the rest of the crop or old crop (Indriani and Sumiarsih, 1999).
Size of seaweed seedlings were planted very influential on the growth rate and seed thallus which is the end will give a growth rate higher than the seedlings thallus of the base. The very end of seaweed showed the greatest rate of photosynthesis compared to other parts of the increasing distance from the end (Glenn and Doty 1981). Atmadja research results and Sulistijo (1977) reported that seeds the tip of the seed that grows faster than any other part, younger seedlings appear to provide the best growth to be used as seed.
The end thallus also contains hormones that much more when compared to the base of the thallus. This hormone plays an important role in the growth of seaweed thallus. Hormones are compounds produced in the plant body, a hormone that most influence on the growth of seaweed, among others:
Auxin on seaweed has a role in regulating many physiological processes, such as growth, division and differentiation of cells and protein synthesis. Auxin is produced in meristimatik network active (ie buds, young leaves and fruit). Auxin activity encourages cell division by influencing the cell wall. Auxin also be away from the light (negative fototaksis). Auxin be produced more in the seaweed that is less exposed to sunlight, such as Figure 8 below. Synthetic auxin has been widely used is hydrasil.
Figure 8. The end thallus kelp, which contains auxin.
Giberalin naturally present in various plant tissues. In addition to engaging in stem growth, giberellin also a major fillip to the growth of roots, shoots, sprouts and flowers. Giving giberellin in low doses is known also able to stimulate plant growth stunted, in a sense overcome the innate nature of the decline (Kimball, 1990). Giberellin as plant hormones in plants affects the genetic nature (genetic dwarfism), flowering, irradiation, pathenocarpy, mobilization of carbohydrate and other physiological aspects.
Giberellin have a role in supporting the extension of the cells, the formation of the enzyme protease, thus freeing tryptophan as an early form of auxin, stimulates synthesis ribonukleas, increases the activity of the cambium and support the formation of new RNA and protein synthesis. Other mechanisms to explain that giberellin supports the formation of α-amylase enzyme thus increasing the sugar content by hydrolysis of starch / starch and automatically increases the osmotic pressure.
As a result, the cells have a tendency to grow. In addition, the resulting sugar can be translocated to the shoots / embryos as a source of energy in the early stages pertumbuhan.Peran giberalin in seaweed, among others, work synergistically with auxin, cytokinins and other substances (synergism), all plant organs containing GA, the richest in fruit and seeds. Giberalin also plays a role in cell division and supports the formation of RNA resulting in protein synthesis. Giberalin activity contained in the broad concentration range, non-toxic / harmful. GA commercial synthesis = GA3, GA7, and GA13
Cytokinins in seaweed play a role in stimulating cell division (cytokinesis) and stimulate mitosis in meristematic tissue, as well as play an important role in the translation process of protein synthesis. Commercial synthetic cytokinin that has been widely used, among others, BA, kinetin and PBA
Figure 9. The end thallus is used as seed seaweed
According Widyastuti and Tjokrokusumo (2004), now widely found synthetic compounds that have a physiological effect similar to a plant hormone. All synthetic plant hormones or synthetic compound that has a physiological and biochemical properties similar to a plant hormone called plant growth regulator (PGR).
Plant hormones and plant growth regulator generally encourage a growth and development. Differences between plant hormones and plant growth regulator compounds are as follows:
(A) Phythohormone or plant hormones are organic compounds not active nutrients in small amounts (<1 mM) were synthesized in certain parts, in general translocated to other parts of the plant where the compound produces a response in biochemical, physiological and morphological.
(B) the plant growth regulator is not the nutrients of organic compounds in low concentrations (<1 mM) promotes, inhibits or qualitatively alter plant growth and development.
(C) inhibitors are organic compounds that inhibit the growth in general and there is no lapse of concentration which may encourage growth.