الفهرس 
Biological functions of plant hemoglobinsOnly 14 pages are availabe for public view
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Abstract
Plant morphogenesis is a biological process by which plant organs such as shoot and root systems or whole plant body can be elaborated. It is considered as the fundamental aspect of plant biology. The elaboration of plant body or organ through morphogenesis is mainly induced by hormones and some environmental factors. This process could be achieved either in vivo or in vitro. In vitro morphogenesis system, which is called plant regeneration, not only could be used for clonal propagation, germplasm culture and plant modification and improvement, but also as a system to study plant development (Hicks, 1994). There are two distinct pathways for in vitro morphogenesis either somatic embryogenesis or organogenesis Somatic embryogenesis means the formation of asexual embryos from somatic cells. In vivo, the developmental sequence of the shape of the embryo body is globular, heart, and torpedo. This sequence of the developmental stages is also observed during in vitro embryogenesis, thereby revealing the existence of common regulatory pathways that guide cell patterning and tissue differentiation in vivo and in vitro. This observation is very important because it allows the use of culture embryos to investigate physiological and molecular events occurring in seed embryos which are are in fact embedded in the maternal tissue and very difficult to dissect.