Leaves originate from the shoot apical meristem, a small mound of undifferentiated tissue at the tip of the stem. Leaf formation begins with the selection of a group of founder cells in the so-called peripheral zone at the flank of the meristem, followed by the initiation of local growth and finally morphogenesis of the resulting bulge into a differentiated leaf. Whereas the mechanisms controll...

In order to select the best tomato cultivar for Agrobacterium mediated gene transformation studies, In vitro regeneration frequency of hypocotyls, leaf disc and shoot tip of five tomato cultivars (Lycopersicon esculentum) was investigated on a regeneration medium supplemented with 1 mg/l zeatin and 0.1 mg/l indole-3-acetic acid. Significant differences in regeneration capacity between genotypes...

Two new species of Fergusobia are described. Both were collected from flat leaf galls from South Australia, one on Eucalyptus microcarpa and the other on E. porosa. Fergusobia microcarpae n. sp. Davies is characterised by the combination of a C-shaped parthenogenetic female with a short, broadly rounded conoid tail, an arcuate to open C-shaped infective female with an hemispherical tail tip, an...

Expression of the tobacco mosaic virus 30-kD movement protein (TMV MP) gene in tobacco plants increases the plasmodesmatal size exclusion limit (SEL) 10-fold between mesophyll cells in mature leaves. In the present study, we examined the structure of plasmodesmata as a function of leaf development. In young leaves of 30-kD TMV MP transgenic (line 274) and vector control (line 306) plants, almos...

Fergusobia tumifaciens (Currie 1937) Wachek 1955, the type species for the genus Fergusobia, is re-described from specimens collected from 'leafy' leaf bud galls on Eucalyptus bridgesiana near Albury in New South Wales, Australia. It is morphologically characterized by the combination of an open C-shaped parthenogenetic female with a small broadly conoid tail, a C-shaped infective female with a...

Pistachio is one of the most important nuts and its mass production using tissue culture techniques is of great importance. Micro-propagation has many complications. Contamination is one of the critical limitations in the establishment stage. This study focused on different NaClO and HgCl2 concentrations and exposure times. Shoot tip necrosis (STN) is one of the most common problems during larg...

Introduction of and invasion by alien plant pathogens represents the main cause of emerging infectious diseases affecting domesticated and wild plant species worldwide. The trade in living plants is the most common pathway of introduction. Many of the alien tree pathogens recently introduced into Europe were not previously included on any quarantine lists. To help determine the potential risk o...