Regeneration and Characterization of Prairie Gentian (Eustoma grandiflorum) Plants Transformed by Agrobacterium rhizogenes.

In November 2012, plants of Russell prairie gentian (Eustoma grandiflorum, Lisianthus russellianus) were collected from a commercial greenhouse in Atibaia, SP, Brazil, displaying necrotic spots on leaves and necrosis on stems, followed by generalized systemic necrosis. Disease symptom incidence was estimated at 10%. Preliminary electron microscopy observations of negatively stained leaf extracts prepared from those lesions revealed the presence of a large number of spherical tospovirus-like, approximately 100 nm in diameter. Samples of infected leaves were ground in 0.01 M phosphate buffer containing 0.5% sodium sulphide and mechanically inoculated in six plants of each species of Nicotiana glutinosa, N. tabacum cv. White Burley, N. megalosiphon, N. debneyii, Datura stramonium, Chenopodium amaranticolor, C. quinoa, and E. grandiflorum. All inoculated plants displayed local lesions 4 to 5 days after inoculation, while N. debneyii and D. stramonium showed systemic symptoms, typical of Tospovirus infection. In addition, E. grandiflorum reproduced the original symptoms. Total RNA was extracted from infected E. grandiflorum and D. stramonium, and reverse transcription (RT)-PCR was performed using universal primers BR60 and BR65 (2) targeting conserved regions of the nucleocapsid gene (N). The amplification products of approximately 450 bp were purified, cloned, and sequenced. The unknown virus was identified as Chrysanthemum stem necrosis virus (CSNV-Lis) based on host range and nucleotide sequence (Genbank Accession No. KC894721) and showed 99% identity with a CSNV chrysanthemum isolate from Japan (AB600872). Maximum likelihood phylogenetic analysis using nine homologous CSNV sequences available in GenBank classified CSNV-Lis into a monophyletic group formed by chrysanthemum isolates from Japan and China while a Japanese lisianthus isolate was separately clustered. CSNV is a member of the genus Tospovirus (Bunyaviridae) and was first reported on chrysanthemum in Brazil (1) and later in the Netherlands, Slovenia, United Kingdom, and Japan (3). Despite scattered recent reports of CSNV, the simultaneous production of chrysanthemum and lisianthus crops along the year by Brazilian farmers has contributed to the virus maintenance in the field. The high identity between Brazilian and Japanese isolates of CSNV suggest a possible reintroduction of the virus through exchange of vegetative propagating material. References: (1) L. M. L. Duarte et al. J. Phytopathol. 143:569, 1995. (2) M. Eiras et al. Fitopatol. Bras. 26:170, 2001. (3) K. Momonoi et al. J. Gen. Plant Pathol. 77:142, 2011.

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Evaluation of Bedding Plant Varieties for Resistance to Phytophthora

Journal of Environmental Horticulture ◽

10.24266/0738-2898-18.1.40 ◽

2000 ◽

Vol 18 (1) ◽

pp. 40-44 ◽

Cited By ~ 1

Author(s):

Thomas J. Banko ◽

Marcia A. Stefani

Keyword(s):

Plant Species ◽

Growing Season ◽

Phytophthora Nicotianae ◽

Eustoma Grandiflorum ◽

Bedding Plant ◽

Zinnia Angustifolia ◽

Prairie Gentian ◽

New Look

Abstract Seedlings of several annual and perennial bedding plant species were inoculated with an isolate of Phytophthora nicotianae (synonym = P. parasitica) and planted into field beds in a simulated landscape situation. Throughout the growing season, growth measurements and disease ratings of the inoculated plants were compared with those of non-inoculated control plants of the same species in identical beds. Phytophthora-inoculated plants that continued to thrive through most of the growing season included Ageratum houstonianum, Celosia ‘Apricot Brandy’, and ‘New Look’; Dahlia ‘Harlequin’; Eustoma grandiflorum (prairie gentian); Lobularia ‘Carpet of Snow’; Nicotiana ‘Alta Dwarf White’, ‘Domino Salmon’, and ‘Nicki Red’; Pelargonium (geranium) ‘Multibloom Scarlet Eye’; Petunia ‘Polo Salmon’, and ‘Sugar Daddy’; Portulaca ‘Sundial Peppermint’; Rudbeckia ‘Rustic Dwarf’; Salvia ‘Lady in Red’, and ‘Victoria Blue’; Tagetes (marigold) ‘Disco Mix’, ‘Inca Orange’, ‘Inca Yellow’, ‘Janie Harmony Improved’, and ‘Gold Fireworks’; and Zinnia angustifolia. Plants that performed poorly following inoculation with Phytophthora include Antirrhinum (snapdragon) ‘Liberty White’, and ‘Liberty Mix’; Catharanthus (vinca) ‘Little Bright Eye’, and ‘Tropicana Rose’; Hibiscus ‘Disco Belle Mix’; Impatiens ‘Accent Bright Eye’; Leucanthemum x ‘Alaska’; Melampodium ‘Medallion’; Salvia ‘Turkestanica’; Torenia ‘Clown Mix’; Verbena ‘Imagination’; and Viola (pansy) ‘Fama See Me’. This study identifies bedding plant taxa which will provide an acceptable display in landscape beds infested with Phytopthora nicotianae (synonym = P. parasitica).

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Genetic Transformation of Plumbago zeylanica with Agrobacterium rhizogenes Strain LBA 9402 and Characterization of Transformed Root Lines

Plant Tissue Culture and Biotechnology ◽

10.3329/ptcb.v25i1.24123 ◽

2015 ◽

Vol 25 (1) ◽

pp. 21-35 ◽

Cited By ~ 9

Author(s):

Amrita Basu ◽

Raj Kumar Joshi ◽

Sumita Jha

Keyword(s):

Agrobacterium Rhizogenes ◽

High Frequency ◽

Scale Up ◽

Rol Genes ◽

Plumbago Zeylanica ◽

Frequency Transformation ◽

Whole Plants ◽

High Frequency Transformation

High frequency transformation (73.80 ± 2.24%) has been obtained in Plumbago zeylanica using nodes and internodes of axenic whole plants infected with Agrobacterium rhizogenes strain LBA 9402. The root lines could be distinguished morphologically into two types : Root lines of morphotypes I and II. While morphotype I showed profuse branching with short (< 1 cm), highly dense hairy laterals, the roots of morphotype II roots were characterized also by profuse branching with long hairy laterals (> 3 ? 4 cm). Only four of the ten root lines showed integration of four rol genes (rolA, rolB, rolC and rolD) of TL?DNA. None of the root lines showed presence of any of the five genes of TR?DNA. It is noteworthy that the root morphotypes (I and II) showed a clear distinction in the nature of integration and expression of rol genes. The transformed root lines varied significantly (p ? 0.05) with respect to DW (GI DW basis, 2.19 ± 0.24 ? 5.31 ± 0.6) after 4 weeks of culture on solid modified MS; and plumbagin contents in root lines (4.81 ± 0.16 ? 6.69 ± 0.34 mg/g DW) were higher than that reported earlier. Transformed root lines of P. zeylanica maintained in vitro on phytohormone devoid medium for over 2 years can be used for scale up studies for the production of plumbagin in bioreactors.Plant Tissue Cult. & Biotech. 25(1): 21-35, 2015 (June)

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