scholarly journals Development, Detection, and Elimination of Verticillium dahliae in Mint Shoot Cultures

HortScience ◽  
2003 ◽  
Vol 38 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Nan Wang ◽  
Barbara M. Reed
Keyword(s):  
Verticillium Dahliae ◽  
Shoot Tips ◽  
Potato Dextrose Agar ◽  
Shoot Length ◽  
Symptom Expression ◽  
Shoot Cultures ◽  
Symptom Development ◽  
Symptom Ratings ◽  
Wilt Symptom

Roots of greenhouse-grown mint plants and in-vitro-grown shoot cultures were inoculated with Verticillium dahliae Kleb. conidial suspensions to study wilt symptom development and detection and elimination of the fungus. There were significant differences in the symptom expression between control and infected shoot cultures at all conidia concentrations for the four mints tested. Disease-symptom ratings were proportional to the V. dahliae inoculum density. Infected shoot cultures were stunted when inoculated with ≥ 103 conidia/mL. Verticillium dahliae was re-isolated from infected shoot cultures at all levels of inoculum, but not from any control cultures. Verticillium infections were easily detected by plating mint stems on potato dextrose agar. Shoot tips (0.5 to 15 mm) from infected in-vitro- and greenhouse-grown plants were isolated and screened for fungus. The most effective shoot length for fungus elimination was 3-5 mm. Shoot tips isolated from in vitro spearmint cultivars infected at 102 and 103 conidia/mL were 100% Verticillium free, but only 42% of `Black Mitcham' and 54% of `Todd's Mitcham' peppermints were free of the disease. Shoot tips from infected greenhouse plants produced Verticillium-free cultures from 79% of `Black Mitcham' and 90% of `Todd's Mitcham' plants. These results indicate the utility of testing for Verticillium and the safety of micropropagated mint shoots for certified planting stock programs.

scholarly journals In vitro Conservation and Cryopreservation of Nandina domestica, an Outdoor Ornamental Shrub

2013 ◽  
Vol 41 (2) ◽  
pp. 638 ◽  
Author(s):  
Aylin OZUDOGRU ◽  
Diogo Pedrosa Corrêa Da SILVA ◽  
Ergun KAYA ◽  
Giuliano DRADI ◽  
Renato PAIVA ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Storage Temperature ◽  
Sucrose Concentration ◽  
Aluminum Foil ◽  
Shoot Tips ◽  
In Vitro Conservation ◽  
Shoot Cultures ◽  
Storage Medium ◽  
Droplet Vitrification

The study focused on an economically-important ornamental outdoor shrub, Nandina domestica, with the aims to (i) optimize an effective in vitro conservation method, and (ii) develop a cryopreservation protocol for shoot tips by the PVS2 vitrification and droplet-vitrification techniques. For in vitro conservation of shoot cultures, the tested parameters were sucrose content in the storage medium (30, 45, 60 g/L) and storage temperature (4 °C or 8 °C). Cryopreservation was performed by applying the PVS2 vitrification solution, in 2-ml cryovials or in drops over aluminum foil strips, for 15, 30, 60 or 90 min at 0 °C, followed by the direct immersion in liquid nitrogen of shoot tips. Results show that N. domestica shoots can be conserved successfully for 6 months at both the temperatures tested, especially when 60 g/L sucrose is used in the storage medium. However, conservation at 4 °C showed to be more appropriate, as hyperhydricity was observed in post-conservation of shoots coming from storage at 8 °C. As for cryopreservation, a daily gradual increase of sucrose concentration (from 0.25 to 1.0 M) produced better protection to the samples that were stored in liquid nitrogen. Indeed, with this sucrose treatment method, a 30-min PVS2 incubation time was enough to produce, 60 days after thawing, the best recovery (47% and 50%) of shoot tips, cryopreserved with PVS2 vitrification and droplet-vitrification, respectively.

scholarly journals In vitro Propagation of Thuja occidentalis Through Apical Shoot Culture

1970 ◽  
Vol 16 (1) ◽  
pp. 5-9
Author(s):  
MH Kabir ◽  
PK Roy ◽  
Golam Ahmed
Keyword(s):  
In Vitro Propagation ◽  
Shoot Culture ◽  
Shoot Length ◽  
Shoot Cultures ◽  
In Vitro Plant Regeneration ◽  
Thuja Occidentalis ◽  
Apical Shoot ◽  
Half Strength ◽  
Morphological Variants

In vitro plant regeneration of Thuja occidentalis was obtained in apical shoot cultures from field grown plants. Hormone free MS medium 100% explants produced shoots. The average number of shoots per explant was 6.57 ± 0.45 and the average shoot length of 4.5 ± 0.27 cm were recorded in this medium. Shoots rooted well when they were transferred into half strength MS with 1.0 mg/l IBA. The average number of root per shoot was 3.92 ± 0.28 and the average root length of 3.64 ± 0.38 cm were observed in this medium. No morphological variants were observed during the passage of in vitro culture.Key words: In vitro, Propagation, Thuja occidentalis, Apical shootDOI = 10.3329/ptcb.v16i1.1099Plant Tissue Cult. & Biotech. 16(1): 5-9, 2006 (June)

scholarly journals In Vitro Responses of Tissues from Rhododendron Plants With and Without Tissue Proliferation

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873D-873
Author(s):  
Yiqin Ruan ◽  
Mark H. Brand
Keyword(s):  
Growth Rates ◽  
Woody Plant ◽  
Shoot Tips ◽  
Shoot Cultures ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Tissue Proliferation ◽  
Long Shoots ◽  
Short Shoots

Rhododendron `Montego' shoot cultures initiated from plants with and without tissue proliferation (TP and NTP) served as explant sources for all studies (Note: in vitro TP shoot cultures produce primarily dwarf shoots, some long shoots, and stem tumors). Calli induced from TP leaves and tumors and NTP leaves were cultured on woody plant (WP) medium containing NAA and 2-iP. During the first 4 weeks of culture, calli from NTP leaves had higher relative growth rates than calli from TP leaves or tumors. However, calli from TP leaves and tumors grew faster than calli from NTP leaves for all subculture periods that followed. Shoot tips (5 mm) were excised from TP dwarf shoots, TP long shoots, and NTP shoots and were cultured on WP medium with or without 15 μM 2-iP. Shoot tips from TP dwarf and long shoots multiplied on medium without 2-iP, averaging 18.4 and 1.7 shoots per shoot tip in 12 weeks, respectively. Shoot tips from NTP shoots only multiplied when maintained on 2-iP-containing medium. When placed on 2-iP-containing medium, both types of TP shoot tips produced clusters of callus-like nodules that gave rise to highly tumorized, short shoots or leafy meristems.

scholarly journals Long-term in Vitro Regeneration of Hamelia patens

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873G-874
Author(s):  
D. Sankhla ◽  
T.D. Davis ◽  
N. Sankhla ◽  
A. Upadhyaya
Keyword(s):  
Culture Medium ◽  
In Vitro Regeneration ◽  
Shoot Formation ◽  
Shoot Tips ◽  
Shoot Cultures ◽  
Ms Medium ◽  
Prolific Shoot ◽  
Ornamental Shrub

This report describes an efficient in vitro regeneration protocol for H. patens (firebush), a heat-tolerant ornamental shrub native to tropical and subtropical America. Shoot cultures were initially established using shoot tips placed on MS-revised medium containing 2.3 μM 2,4-D, 2.3 μM kinetin, and 0.25% polyvinylpyrrolidone. Other types of explants (nodal and internodal segments, leaf pieces, floral buds) did not regenerate shoots when placed on this medium. Two-month-old plantlets derived from the shoot tips were subcultured on MS medium supplemented with 0.5 μM thidiazuron (TDZ), and within 3 to 4 weeks, some callus was produced at the root–shoot junction. When this callus, with a small portion of the root and shoots, was placed on MS medium with 0.05 μM TDZ and 0.01 μM ABA, prolific shoot formation occurred within 3 to 4 weeks followed by root formation. By regular subculturing every 5 to 6 weeks, hundreds of plantlets have been obtained over the past 3 years with no apparent decline in regeneration potential. Addition of activated charcoal (0.5%) to the culture medium has greatly improved growth of the plantlets.

Verticillium wilt of chrysanthemum: colonization of leaves in relation to symptom development

1971 ◽  
Vol 49 (2) ◽  
pp. 181-185 ◽  
Author(s):  
R. Hall ◽  
L. V. Busch
Keyword(s):  
Verticillium Wilt ◽  
Significant Contribution ◽  
Vascular System ◽  
Symptom Expression ◽  
Rapid Rise ◽  
Symptom Development ◽  
Flower Buds ◽  
Advanced Stages ◽  
Wilt Symptom ◽  
Leaf Exudate

The vascular system of leaves of chrysanthemum plants inoculated with Verticillium dahliae was invaded by mycelium before the appearance of visible wilt symptoms. After flower buds appeared a rapid rise in the number of propagules of fungus in the leaf was followed by a rise in severity of visible wilt symptom expression and conductivity of leaf exudate. Those portions of the leaf with the most advanced stages of wilt contained the greatest amounts of fungus. It is suggested that the mycelium within the leaf makes a significant contribution to the development of symptoms of wilt.

Ultrastructure of wilt syndrome caused by Verticillium dahliae. III. Chronological symptom development in sunflower leaves

1977 ◽  
Vol 55 (2) ◽  
pp. 139-152 ◽  
Author(s):  
Jane Robb ◽  
Lloyd Busch ◽  
Jean D. Brisson ◽  
B. C. Lu
Keyword(s):  
Phenolic Compounds ◽  
Verticillium Dahliae ◽  
Temporal Order ◽  
Band 3 ◽  
Xylem Vessel ◽  
Ultrastructural Changes ◽  
Symptom Expression ◽  
Symptom Development ◽  
Mesophyll Tissue ◽  
Foliar Symptom

When sunflowers are infected by the vascular pathogen Verticillium dahliae, the first visible foliar symptom is the appearance of tiny chlorotic flecks. An attempt was made to determine the temporal order in which early ultrastructural changes leading to symptom expression occur. The evidence indicates that ultrastructural changes occur in the following order: (1) degradation of xylem vessel walls, (2) initiation of the necrotic band, (3) degeneration of the mesophyll tissue remote from the vein, and (4) degeneration of the phloem. The possible importance of xylem vessel plugs and of phenolic compounds to the initiation of symptom development is also discussed.

scholarly journals In vitro propagation of pointed gourd (Trichosanthes dioica Roxb.) through encapsulated shoot tips

1970 ◽  
Vol 34 (4) ◽  
pp. 555-563 ◽  
Author(s):  
MA Malek
Keyword(s):  
Sodium Alginate ◽  
Basal Medium ◽  
Shoot Proliferation ◽  
Alginate Beads ◽  
Multiple Shoot ◽  
Shoot Tips ◽  
Shoot Cultures ◽  
Artificial Seed ◽  
Pointed Gourd

Plants were regenerated from encapsulated shoot tips of pointed gourd. Shoot tips isolated from multiple shoot cultures of AM-8 and AM-15 cultivars of pointed gourd were encapsulated in sodium alginate beads. For germination and shoot proliferation, encapsulated shoot tips (artificial seed) were cultured in MS basal medium containing different concentrations and combinations of BAP and NAA. Use of MS medium resulted in 90% conversion of encapsulated shoot tips into plantlets. The results exhibited that BAP and combinations of BAP and NAA play an important role in germination of artificial seed being encapsulated by sodium alginate beads. The plantlets were successfully established in earthen pot. Under the present study, limited experimental efforts have been made to establish the protocol for encapsulating the shoot tips for the production of artificial seed and their subsequent regeneration. It is the first report in Bangladesh in developing artificial seed production technique using vegetative tissue of pointed gourd. Key Words: In vitro propagation; pointed gourd; shoot tips. DOI: 10.3329/bjar.v34i4.5832Bangladesh J. Agril. Res. 34(4) : 555-563, December 2009

scholarly journals The Effect of Culture Physical Conditions and Explant Type and Source on the Growth and Multiplication of Ficus benjamina in Vitro

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873F-873
Author(s):  
N.S. Al-Khalifah ◽  
P.G. Alderson
Keyword(s):  
Light Intensity ◽  
Shoot Multiplication ◽  
Shoot Elongation ◽  
Shoot Length ◽  
Axillary Buds ◽  
Shoot Cultures ◽  
Variable Response ◽  
Ficus Benjamina ◽  
Chlorophyll Contents

Shoot cultures of Ficus benjamina cv. Cleo showed a variable response to light intensity in the range of 8 to 50 μmol–m–2–s–1. The highest leaf area occurred at 15 μmol–m–2–s–1 and shoot length and chlorophyll contents increased with the decrease of light intensity. Incubating explants for 8 weeks at 25 and 35C showed that shoot length increased at 35C; however, shoot multiplication, leaf number, root number, and callus weight were higher at 25C. Shoot-tip explants were superior to axillary buds when cultured or subcultured for shoot elongation, whereas axillary buds were better for shoot multiplication. Shoot tips with two or three small leaves appeared to be the best explants for fast growth and healthy cultures of F. benjamina.

Verticillium wilt of chrysanthemum: suppression of fungal colonization of leaves and prevention of wilt symptom development by foliar applications of benomyl

1971 ◽  
Vol 49 (11) ◽  
pp. 1987-1991 ◽  
Author(s):  
Lloyd V. Busch ◽  
Robert Hall
Keyword(s):  
Verticillium Wilt ◽  
Fungal Growth ◽  
Tween 20 ◽  
Fungal Colonization ◽  
Systemic Fungicide ◽  
Symptom Expression ◽  
Symptom Development ◽  
Fungal Activity ◽  
Single Leaf ◽  
Wilt Symptom

This report describes the use of a systemic fungicide in a study of the relation between fungal colonization of a plant and symptom expression. The systemic fungicide benomyl (methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate) was used to selectively suppress development of Verticillium dahliae in leaves of chrysanthemum plants infected via the roots.Benomyl sprayed or painted onto foliage at weekly intervals as a 20 mg/liter solution in 0.25% aqueous Tween 20 restricted development of V. dahliae in leaves and prevented wilt symptom development. Numbers of propagules of V. dahliae recovered from stems of symptomless benomyl-treated plants were similar to those recovered from stems of untreated inoculated plants expressing wilt symptoms. Material toxic to Verticillium was detected in leaves but not in stems of plants receiving foliar paint applications of benomyl. Benomyl applied repeatedly to a single leaf on an inoculated plant suppressed fungal growth and symptom development in that leaf while untreated leaves wilted and became necrotic in the usual way. The observations support the hypothesis that symptom expression in leaves of chrysanthemum plants infected with Verticillium is largely due to fungal activity within infected leaves rather than fungal activity in the roots or stem.

scholarly journals Apple Micrografting Protocol to Establish Transgenic Clones on Field Ready Rootstock

2003 ◽  
Vol 13 (4) ◽  
pp. 641-646 ◽  
Author(s):  
W. David Lane ◽  
Basdeo Bhagwat ◽  
Susan Wahlgren ◽  
John D. Armstrong
Keyword(s):  
Side Branch ◽  
Shoot Tips ◽  
Shoot Cultures ◽  
Back Side ◽  
Wedge Shape ◽  
Nursery Trees ◽  
In Vitro Shoot Cultures ◽  
Screen House

A protocol for micrografting shoot tips harvested from in vitro shoot cultures directly to transplanted rootstock plants in the greenhouse was developed. Shoot tips of the apple (Malus domestica) cultivars Golden Delicious, Granny Smith and Fuji clone, Nagafu12, were harvested, stored in a water bath then prepared for grafting by cutting the stem immediately below the tip into a wedge shape leaving the tip approximately 3 mm (0.12 inch) long. The rootstock cultivar, Malling 9 (M.9) (M. domestica), was prepared by cutting into a young fast growing side branch to expose the cambium, creating a pocket into which the shoot tip was inserted. The cut section of the tip was oriented so as to contact the exposed rootstock cambium and was held in place by wrapping with a strip of pliable plastic film. Two weeks later the wrapping was loosened and the grafted branch cut back. Side branches of the rootstock were not removed until later in order to support rootstock growth. The scion shoots developed into nursery whips suitable for transplanting to a screen house or field after 2 months. The protocol proved to be a simple efficient way to rapidly grow nursery trees from tissue culture clones developed in genetic modification experiments and was used to propagate several hundred plants. Grafting success was often 100% but was reduced if quality of shoot tips was poor due to injury indicated by brown tip color. The protocol eliminates the steps of rooting, acclimatizing and growing shoots into plants to serve as a scion wood source.

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