Mandela, the former president of the Republic of South Africa and Nobel Peace laureate, spent more than 40 yearsâ27 of them in prisonâas a central figure in the struggle against South Africaâs brutal and restrictive racial regime called apartheid.
meristem culture. (shoot-tip culture) The culture of excised meristems on suitable nutrient media under aseptic conditions. The stem apex is usually used though axillary meristems may also be taken.Often gibberellic acid must be added to the medium to promote normal growth into a plantlet.shoot-tip culture) The culture of excised meristems on suitable nutrient media under aseptic conditions. The stem apex is usually used though axillary meristems may also be taken. Often gibberellic acid must be added to the medium to promote normal growth into a plantlet.
On the basis of origin and development of initiating cells, meristems can be divided into three types: (i) Promeristem or priordial meristem: A group of young meristematic cells of a growing organ. It is the early embryonic meristem from which other advanced meristems are derived. In a plant, it occupies a small area at the tip of stem and root. It further divides to form primary meristem. (ii) Primary meristem: These are derived from promeristem. They are present below the promeristem at shoot and root apices. These cells divide and form permanent tissues. (iii) Secondary meristem: