Paradox (Juglans hindsii × J. regia), the dominant rootstock used in California, USA walnut production, has many desirable horticultural characteristics, but is highly susceptible to crown gall. Crown gall, caused by the bacterium Agrobacterium tumefaciens, is not consistently controlled with soil fumigation. This observation, in conjunction with observations of galls occurring in above ground ...

The present study investigated to evaluate the potential of liquid chitosan three concentrations (0.5, 1 and 2%) on Meloidogyne incognita (Kofoid White, 1919) Chitwood, 1949 in vitro tomato under controlled conditions ((24 ± °C, 60 5% humidity). In assay, effect suppressing hatching from eggs second juvenile larvae (J2) mortality was determined. reducing number gall egg mass roots J2 density so...

Clubroot disease causes gall formation on Brassica roots. A holistic approach was undertaken to understand the role of plant hormones in early clubroot symptom development in Arabidopsis. We used the CYCB1;1::GUS, DR5::GUS and ARR5::GUS constructs to assess clubroot initiation. We compared plant hormone concentration between control and infected plants, screened different hormone mutants for re...

Clubroot symptoms were frequently observed on roots of shepherd's-purse (Capsella bursa-pastoris) grown in a field in Nonsan, Chungnam province, Korea in March, 2009. Many resting spores were found in the cells of the root gall tissues collected from the field. The clubroot pathogen was identified as Plasmodiophora brassicae based on its morphological and pathological characteristics. This is t...

Advances made recently in the study of plant growth substances and their function in normal growth have raised the question of their possible role in atypical and pathological growth and specifically in the gall development induced by Phytomonas tumefaciens (Smith and Town.) Bergey et al. A suggestion of their presence was first given by the marked epinasty of leaf petioles in plants inoculated...

Pathogenesis of M. chitwoodi associated with potato (Solanum tuberosura cv. Russet Burbank) followed a pattern characteristic of root-knot nematodes. Giant ceils developed in the phloem tissues of roots, stolons, and tubers and appeared to arise by hypertrophy and karyokinesis rather than cellular fusion. Gall formation was a function of parasite density and developed by hypertrophy of cortical...

Root knot and cyst nematodes induce large multinucleated cells, designated giant cells and syncytia, respectively, in plant roots. We have used molecular markers to study cell cycle progression in these specialized feeding cells. In situ hybridization with two cyclin-dependent kinases and two cyclins showed that these genes were induced very early in galls and syncytia and that the feeding cell...

Isfahan Agriculture Research Center, I.R. Iran * Corresponding author’s e-mail: [email protected] Abstract The survey conducted to assess the incidence of root-knot disease on tomato in 8 localities in and around Aligarh (India) showed that the crops of tomato in all the 8 localities were infected with root-knot nematodes. Highest frequency (90%) was found in Idgah area, closely followe...