抽象的

Effect of Light Irradiance on Regulation of Leaf Senescence

Mohy Eldeen Nour Eldaime Elgimabi

Gymnosperms are the plants of the remarkable evolutionary history; they have the great empire in the Mesozoic era, however at the beginning of the cenozoic, one can see the degradation in the vegetation (decline of the gymnosperm). In recent era the gymnosperms are presented by the cycadales (only 11 genera very endemic distribution) coniferales, Gnetales, they have the great assemblages (combination of the primitive as well as the advanced features or attributes) of the characters, in this review articles we are going to present one of the coniferales entitled as Larix. These plants have the long distribution in the European alps mountains forests), large belt of the lorchs forms the magnificent flora of the alps mountains (great physiognomy and the dominance are the peculiar features). However, in this era, in India (Himalayas belt) and the other part of the world these primitive reservoirs of the plants are going to be rapid degradation, so these plant lines needs conservation and propagation, so that the unique line of assemblage of primitive evolutionary characters (near to extinct) can be preserved. This review article represents some of the aspects of the Larix conifer and there threats and conservation.