ISOLATE TWO SPECIES OF COMPOSITAE FAMILY E.armatus BOISS&HAUSSKN AND E.cephalotes DC. BY MORPHOLOGICAL AND VEGETATIVE SHOOT APEX FOR THE FIRST TIME IN IRAQ

Present study delts with morphological and vegetative shoot apex characteristics of two species Echinops armatus and E.cephalotes (compositae) which collected during trips field to the northern areas of Iraq in the seasons of growth 2012-2014. As it presents the results and characters had been shown for the first time in Iraq. plant species are perennial herbs spinous with woody, strong and solid stems that covered with many types of indumentums like spines and hairs, the study included characters of stems, leaves, involucres bracts and inflorescences as well as characters of growing points of the two species, and by examining buds in inflorescences found that the flowers are hermaphrodite, not sterile which containing all the reproductive organs like stamens, pollen grains, pistils and ovaries, an early dehesence as mature anthers and bloom before the maturation of pistils and disperse their pollen.The study also discussed variations within the characters and it became clear that the characters of leaves, stems and involucres especially inner cycle, including the importance of taxonomic great isolate the two species. Ranged prepare involucres braces in the first species is (20-23) bracts while the number varied between (19-20) bracts in the other one. The study showed the importance of growing points in isolating the two species where characterized by two meristematic area in longitudinal embryos species. The first spices recognized by two rows of cells, while the other one marked three rows or layers of components of Tunica cells area, and ensures find accurate measurements of parts phenotypic as well as illustrations of morphological and anatomical parts studied.

Early increased expression of a cyclin-dependant protein kinase (LtCDKA1;1) during inflorescence initiation of the long day grass Lolium temulentum

Knowing where and when different genes express at the shoot apex during the transition to flowering will help in understanding this developmental switch. The CDKA family of serine/threonine kinase genes are appropriate candidates for such developmental switching as they are involved in the regulation of the G1/S and G2/M boundaries of the cell cycle (see review by Dudits et al. 2007) and so could regulate increases of cell division associated with flowering. Furthermore, in rice stems the gibberellin (GA) class of plant growth regulators rapidly upregulate CDKA expression and cell division. Thus, CDKA expression might be linked to the florigenic action of GA as a photoperiodically-generated, signal. For the grass Lolium temulentum L., we have isolated an LtCDKA1;1 gene, which is upregulated in shoot apices collected soon after the start of a single florally inductive long day (LD). In contrast to weak expression of LtCDKA1;1 in the vegetative shoot apex, in situ and PCR-based mRNA assays and immunological studies of its protein show very rapid increases in the apical dome at the time that florigenic signals arrive at the apex (<6 h after the end of the LD). By ~54 h LtCDKA1;1 mRNA is localised to the floral target cells, the spikelet primordia. Later both LtCDKA1;1 mRNA and protein are most evident in floret meristems. Only ~10% of cells within the apical dome are dividing at any time but the LD increase in LtCDKA1;1 may reflect an early transient increase in the mitotic index (Jacqmard et al. 1993) as well as a later increase when spikelet primordia form. Increased expression of an AP1-like gene (LtMADS2) follows that of LtCDKA1;1. Overall, LtCDKA1;1 is a useful marker of both early florigenic signalling and of later morphological/developmental aspects of the floral transition.

Floral morphogenesis and proliferation in Poa labillardieri (Poaceae)

Inflorescence and spikelet development in Poa labillardieri Steud. were investigated by scanning electron microscopy. Thirteen developmental stages were described in detail, starting with the vegetative shoot apex which was shown to be of the short type (stage zero), followed by a conversion from vegetative to floral meristem at Stage 1 and ending at Stage 12, with a mature panicle consisting of a variable number of florets at anthesis within each spikelet. The occurrence of short-type vegetative apices in this perennial grass adds further support to the view that there is no correlation between life span and the apex type. The branches of the P. labillardieri panicle are formed in acropetal succession; however, it is the upper branches that first bear rudiments of the spikelets, starting at the tip of the branches. In contrast differentiation of florets within each spikelet occurs in acropetal succession, so that the basal floret is farthest advanced and each successively upper floret less advanced. P. labillardieri occasionally produces inflorescences containing spikelets in which some or all of the florets are replaced by a plantlet that is structurally similar to a vegetative tiller. Proliferous development ranged from a situation where all florets were converted to vegetative propagules that can be detached and rooted readily in soil, to cases where proliferation extended only as far as an enlargement of the lemma, with either functional or non-functional sexual organs in its axil. Under greenhouse conditions, there was a shift from occasional cases of partially proliferating spikelets that occur in the wild to complete vigorous proliferation stimulated by unknown factor(s). Departure from the normal sexual pattern took place from early Stage 5 (initiation of spikelet primordial) to late Stage 6 (differentiation of florets).