Meristem Culture

DISCUSSION

The first process to do is meristem culture. Cultivation of axillary or apical shoot meristems, particularly of shoot apical meristem, is known as meristem culture. Meristem culture involves the development of an already existing shoot meristem and subsequently, the regeneration of adventitious roots from the developed shoots. It usually does not involve the regeneration of a new shoot meristem.

The expunge meristem can be cultured aseptically on agar solidified simple nutrient medium or on paper bridges dipping into liquid medium and under certain conditions will develop out directly into a small leafy shoot or multiple shoots. Alternatively, the meristem may form a small callus at its cut base on which a large number of shoot

Over time, progenitor cells move out of the tissue onto the surface of the dish. These primary cells can then be further spread and shift into fresh dishes through micropropagation.

Explant culture can also refer to the culturing of the tissue pieces themselves, where cells are left in their enclosing extracellular matrix to more precisely mimic the in vivo environment e.g. cartilage explant culture, or blastocyst implant culture.

The scientist who have struggle to recover pathogen-free plants through tissue culture techniques have instinctively pattern the explants required to take up cultures as ‘shoot-tip', ‘tip-meristem' and ‘meristem-tip'. The apical meristem of a shoot is the portion lying distal to the youngest leaf primordium, it measures up to about 100µm in diameter and 250µm in length. The apical meristem together with one to three young leaf primordia, measuring 100-500µm, constitutes the shoot-apex (Figure 7.2A and B). Although the chances of abolish viruses is higher through ‘meristem' culture, in most successful reports virus-free plants have been got by culturing 100-1000µm long explants which could be according to the above definition is referred as ‘shoot-tip'. To differentiate it from the in vivo technique of propagation through shoot-tip cuttings, the term ‘meristem-tip' culture has been favored for in vitro culture of small

However, secreted, soluble signal molecules play a vital role. It has most been recognised that conditioned medium from embryogenic cultures can enveloped embryogenesis. Active components in the conditioned medium include endochitinases, arabinogalactan proteins and lipochitooligosaccharides.

The possible function and importance of in vitro somatic embryogenesis and organo-genesis are more or less related. The mass creation of adventitious embryos in cell culture is still noticed by many as the optimal propagation system. The adventitious embryo is a bipolar structure that refined directly into a complete plantlet and there is no use for a divided root¬ing phase as with shoot culture.

Somatic em¬bryo has no food reserves, but good nutrients could be wrapped by coating or encapsulation to form some kind of artificial seeds. Such ar¬tificial seeds produce the plantlets directly into the field. Unlike organogenesis, somatic embryos may amerge from single cells and so it is of personal significance in mutagenic studies.

Plants derived from asexual embryos may in some cases be free of virus and other pathogens. For an example, Citrus plant proliferation from embryogenic callus of nuclear origin is free of virus. So it is another way for the production of disease-free