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Volume 2 Numbers 1 & 2 2008
CONTENTS AND ABSTRACTS
Number 1
Naser Alemzadeh Ansari, Mozhgan Zangeneh (Iran) Effects of Cultivar, Harvesting Date and Chemical Treatments on the Quality and Soluble Carbohydrate Contents in Rose (Rosa hybrida) (pp 1-4)
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ABSTRACT
Original Research Paper: Cut rose flower quality decreases after 3-4 days from harvest. To reduce postharvest losses, this experiment was conducted on two rose cultivars (‘Ilona’ and ‘Noblesse’), which grow under subtropical climatic conditions in Khuzestan province of Iran. Each rose cultivar was harvested on three dates two years apart. Chemical treatments included benzyladenine (BA) (10, 20 and 30 mg l-1) and silver thiosulfate solution (STS) (0.2, 0.4 and 0.6 mM) with a combination of 300 mg l-1 8-hydroxyquinoline citrate and 2% sucrose for 24 h. The effect of these treatments on vase life and flower quality of cut rose flowers was evaluated daily. The effects of chemical treatments were investigated by a pulsing method. Vase life, flower diameter, bud opening, concentration of leaf and petal soluble carbohydrate content of cut rose flowers treated with STS and BA increased, and bent neck decreased. Maximum and minimum vase life and quality were in the first and third harvesting date, respectively. Vase life and quality of cv. ‘Noblesse’ was better than ‘Ilona’.
Shigeru Satoh, Noboru Suetome, Sukeyasu Namura, Hideki Kuwabara (Japan) Prolonged Vase Life of Dianthus superbus by 2-Aminoisobutyric Acid and cis-Propenylboric Acid (pp 5-8)
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ABSTRACT
Original Research Paper: Dianthus superbus flower is ‘the Wild Flower of Kyoto Prefecture’, the most historical place in Japan. Although the use of this plant as a potted ornamental and cut flower is increasing, little information is available about the postharvest performance of the cut flower of this species. This study showed that treatment of cut D. superbus flowers with 2-aminoisobutyric acid, an inhibitor of ethylene biosynthesis, or cis-propenylboric acid, a possible inhibitor of ethylene action, delayed the onset of flower senescence (wilting of petals), resulting in the prolonged vase life of the flowers.
Malabika Roy Pathak, Riyad Yousif Hamzah (Kingdom of Bahrain) RAPD Analysis of Date Palm Cultivars of Bahrain (pp 9-11)
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Short Communication: The date palm (Phoenix dactylifera L.) is a monocotyledonous woody perennial plant that plays an important socio-economic role in Middle Eastern countries. The identification and evaluation of genetic variability between cultivars of date palm on the basis of morphological and biochemical markers are difficult, time-consuming and provide limited information. The aim of this study was to detect genetic variability in different cultivated date palm populations around the city of Manama in Bahrain. Random amplified polymorphic DNA (RAPD) was applied to study the genetic diversity in date palm plants. The leaves were colleted in the fruiting stage from ten different plants. Twenty different RAPD primers were used in the experiment and among them only three showed polymorphism and reproducible results. The plants were distinguished by their unique banding patterns produced by the three primers. Analysis of molecular variance (AMOVA) by a similarity matrix showed 52% average genetic similarity among the tested plants. Cluster analysis by the unweighted paired group method of arithmetic mean (UPGMA) detected two clusters and the phylogenetic relationships between the plants were demonstrated by a dendrogram. Our results suggest the presence of a moderate level of genetic variation within the cultivated plants of Bahrain in Manama.
Omid Karami, Parisa Ostad-Ahmadi (Iran) Morphology, Histology and Protein Patterns in Embryogenic and Non-Embryogenic Callus of Carnation (pp 12-13)
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Short Communication: Somatic embryogenesis is a very useful system for studying basic biochemical, physiological and morphological aspects of plants. During somatic embryogenesis induction in carnation (Dianthus caryopyllus L.) cv. ‘Nelson’ two types of callus, embryogenic and non-embryogenic, were observed. The goal of this work was to compare the most relevant characteristics between these two callus types for a better understanding of the mechanism of somatic embryogenesis in carnation. Morphological and histological characteristics of both callus types were different. Morphohistological observations indicated a correlation between the morphological features of clusters and their embryogenic competence. On the other hand, protein patterns observed by SDS-PAGE showed differences that can explain that disparity. We propose that differential protein patterns can modulate the embryogenic capacity of carnation cells and that the number of proteins turned off in somatic cells to allows for the change from a somatic to an embryogenic state.
Number 2
Focus on turfgrasses
Mitsuro Hyakumachi, Toshihiro Hayakawa (Japan) New Isolates of Rhizoctonia Diseases of Turfgrasses (pp 14-24)
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Invited Review: Among the major pathogens of a broad range of turfgrass species, Rhizoctonia spp. are known as causal agents of important turf diseases. Recently, several new Rhizoctonia diseases of turfgrasses have been found. These have included “brown ring patch” on cool-season turfgrasses, “Waitea reddish-brown patch” on cool-season turfgrasses and “spring rot” on warm-season turfgrasses. Causal pathogens of these diseases were identified and that W. circinata var. circinata, Rhizoctonia sp. closely related to W. circinata and the binucleate Rhizoctonia AG-D subgroup III are the casual agents, respectively. Furthermore, causal pathogens of the already known Rhizoctonia diseases such as “large patch” and “Rhizoctonia patch (elephant foot print)” on warm season turfgrasses have been reconsidered and now identified as R. solani AG 2-2 LP and binucleate Rhizoctonia AG-D, subgroup II, respectively. Identification of new groups of Rhizoctonia as pathogens is mainly possible due to the introduction of the molecular techniques for grouping of this genus. In this paper, these recently found Rhizoctonia diseases of turfgrasses are introduced and taxonomical aspects of Rhizoctonia spp. are discussed.
Hassan Salehi, Mohammadreza Salehi (Iran), Mariam B. Sticklen (USA) Tissue Culture and Genetic Transformation of Some Turfgrass Genera (pp 25-31)
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Invited Mini-Review: Tissue culture and genetic transformation of some turfgrass genera are reviewed. Our recent reports are also included in detail. Four turfgrass genera were used, namely common bermudagrass, Cynodon dactylon (L.) Pers. (California origin); strong creeping red fescue, Festuca rubra L. var. rubra ‘Shadow’; perennial ryegrass, Lolium perenne L. ‘Barbal’; and Kentucky bluegrass, Poa pratensis L. ‘Merion’. After acid treatment and surface sterilization, seeds were cultured on Murashige and Skoog (MS) basal medium supplemented with 40 µM dichlorophenoxyacetic acid (2,4-D) for Cynodon and Poa, 150 µM 2,4-D for Lolium and 200 µM 2,4-D for Festuca. Acid treatments improved both callus production percentage and rate, compared to control. Cynodon had the highest callus production rate and thereafter were Lolium, Poa, and Festuca. Cynodon had the best callus production in light and the other genera in dark conditions. In the second experiment, callus induction and plant regeneration were studied in turfgrass genera used. Mature seeds were surface-sterilized and cultured on MS medium supplemented with 30 to 250 µM 2,4-D for callus induction. Regeneration medium consisted of MS supplemented with 5 to 10 µM 6-benzyladenine (BA). Among the genera, Poa had the highest callus induction percentage regardless of 2,4-D concentration, followed by Cynodon, Lolium and Festuca. Cynodon and Lolium had the highest callus regeneration percentage and overall regeneration rate. Reported transformation studies on the genera used are discussed in the text.
Robert C. Michitsch, Calvin Chong, Bruce E. Holbein, R. Paul Voroney, Hua-Wu Liu (Canada) Fertigation of Cool Season Turfgrass Species with Anaerobic Digestate Wastewater (pp 32-38)
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Original Research Paper: Wastewater, derived from the anaerobic digestion of MSW and containing high contents of essential plant nutrients, was used as a primary N source for turfgrass cultivation. Creeping bentgrass (Agrostis palustris Huds.) and Kentucky bluegrass (Poa pratensis L.) were grown under controlled growth room conditions and fertilized with nutrient solution supplied from wastewater or from a commercial soluble turf fertilizer. Bentgrass supplied with wastewater-N grew similarly to those plants supplied with commercial-N in the second of three clipping harvests. In the third harvest, bentgrass supplied with wastewater-N slightly outperformed those fertilized with commercial-N. In the first harvest of bentgrass, as well as with all three harvests of bluegrass, clipping yields were comparable up to the recommended N application rate of 25 kg N·ha-1, while at higher rates, growth with commercial-N exceeded that with wastewater-N. Poor plant growth response at high rates of wastewater addition was related to high concentrations of soluble salts in the wastewater. Field trials were also conducted on three established turfgrass plots typical of PGA regulation turf. Green-area turf was treated with fertilizer solutions supplied at 25, 50, and 100 kg·ha-1 from each of commercial-N, wastewater-N, wastewater-N + calcium nitrate, or 50 kg·ha-1 of a granular control fertilizer. Landing- and rough-area turf received half of each of these rates of N. All turf areas receiving the recommended or lower rates of N performed as well with wastewater-N versus commercial-N. Response of shoot chlorophyll content followed a similar trend as clipping yields, while soil moisture and shoot color were not significant for any treatment on any area.
Agata Jędrzejuk, Aleksandra Łukaszewska (Poland) Winter Forcing Affects Anther Development in Common Lilac (Syringa vulgaris L.) (pp 39-43)
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Original Research Paper: Forcing is a method used by growers to induce plant flowering independently of their natural blooming time. In common lilac (Syringa vulgaris), depending on the depth of dormancy, temperatures required for forcing at the beginning of the forcing cycle are 37°C in November, 31°C in December, and 25°C in January. Such high temperatures, close to the heat shock threshold, may affect pollen development and lead to its atrophy causing anther sterility. In this article we present observations on anther development in flower buds collected from common lilac shrubs forced in autumn and winter. During early forcing, the development of flower buds was inhibited in certain parts of panicles. In florets from such inhibited panicle branches, anther necrosis was observed. It first appeared in the place where the anther parietal layers should be differentiated but eventually it covered the entire anther. In several anthers, microspore tetrads or young microspores with protoplast atrophy were present. In anthers collected from visually normal florets, empty microspores and precocious tapetum degradation were observed. Unlike pollen from unforced shrubs, pollen from forced shrubs did not germinate in vivo. We conclude that forcing conditions, especially temperature, affect anther development and lead to male sterility due to tapetum and microspore degradation. High temperatures delay the development of some flower buds located in the basal and middle part of the panicle thus disturbing proper branching and lower panicle quality.
Ravindra B. Malabadi (Canada/India), Jaime A. Teixeira da Silva (Japan), K. Nataraja, Gangadhar S. Mulgund (India) Shoot Tip Transverse Thin Cell Layers and 24-Epibrassinolide in the Micropropagation of Cymbidium bicolor Lindl. (pp 44-48)
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Original Research Paper: The rapid clonal propagation of Cymbidium bicolor was achieved by induction of protocorm-like-bodies (PLBs) using transverse thin cell layers of shoot tips when cultured on 24-epibrassinolide (24-epiBL)-supplemented Mitra et al. (1976) basal medium. The highest percentage of explants (86.0%) producing PLBs (65.0 ± 3.9) was recorded when 3.0 µM 24-epiBL was used. All the newly formed PLBs survived and after nearly 12 weeks, small bud-like structures formed healthy shoots. Shoots produced roots when cultured on the same basal medium supplemented with 2.0 µM triacontanol. The well-rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1) and 100% survival rate was achieved. This is only the second report of the use of 24-epiBL, a plant steroid lactone, in the micropropagation of orchids.
Ranjana Kapoor, Surinder Kumar, Jitender Kumar Kanwar (India) Bulblet Regeneration from Leaf and Internode Explants of Oriental Hybrid Lilies (pp 49-51)
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Short Communication: Bulblets were regenerated in two oriental lily hybrid cultivars ‘Siberia’ and ‘Marco Polo’ from leaf and internode explants cultured on Murashige and Skoog (MS) medium supplemented with a-naphthalene acetic acid (NAA) and 6-benzyladenine (BA) singly, or in combination. Bulblet regeneration and average fresh weight per bulblet was highest with 1 mg/l NAA and 0.5 mg/l BA in both cultivars, whereas the number of bulblets per explant was greater with 0.2 mg/l NAA and 0.5 mg/l BA. Bulblet regeneration, the number of bulblets per explant and fresh weight was greatest in leaf than internode explants. The bulblets attaining 14 to 16 cm in size flowered in the second year of growth period without any phenotypic variations.
Evgenij V. Mokshin, Alexander S. Lukatkin (Russia), Jaime A. Teixeira da Silva (Japan) Aseptic Culture and Simple, Clonal Micropropagation of Ficus elastica Roxb. (pp 52-54)
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Short Communication: In vitro propagation is an important means to multiply the ornamental plant, Ficus elastica Roxb. This method has certain features which resemble the methodology used for the establishment of F. elastica cultures in vitro. Our objectives were to: a) establish optimum sterilization procedure; b) optimize indole-3-acetic acid (IAA) and 6-benzylaminopurine (BAP) ratios; c) scale-up shoot culture to create a micropropagation system. Maximum number of shoots (24 shoots/explant) and maximum shoot length (1.4 cm) were achieved when explants (shoot tips) were cultured on Murashige and Skoog basal medium with 0.7% agar, the vitamins thiamin and pyridoxine (1 mg/l each), ascorbic acid (15 mg/l), 1.5 mg/l BAP and 1.5 mg/l IAA. This ideal medium was then applied to the micropropagation of F. elastica in which slightly higher values of shoot (24 shoots/explant and 1.5 cm in length) and root parameters were obtained.
Sunil Kumar Senapati, Anuradha Mahapatra, Gyana Ranjan Rout (India) In Vitro Mutation in Rosa hybrida cv. ‘Pusa Gaurav’ and Selection through RAPD and ISSR Markers (pp 55-59)
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ABSTRACT
Original Research Paper: Apical and axillary meristems of Rosa hybrida cv. ‘Pusa Gaurav’ were pretreated with various concentrations (0, 5.0, 10.0, 15.0, 20.0, 25.0, 30.0 µM) of oryzalin (C12H18N4O6) to induce variation in vitro. Depending on the concentration of oryzalin used, the mean survival rate of meristem culture decreased from 98.9% (5.0 µM, 0 h) to 9.85% (30 µM, 36 h), but the lethal dose (LD50) was 20 µM oryzalin pretreated for 24 h. Oryzalin-treated microshoots were used to multiply shoots. The maximum rate of shoot multiplication occurred on Murashige and Skoog (MS) medium supplemented with 2 mg/l BAP (6-benzylaminopurine), 0.25 mg/l IAA (indole-3-acetic acid), and 50 mg/l Ads (adenine sulfate) and 20 µM oryzalin. The elongated shoots were rooted in half-strength MS medium supplemented with 0.25 mg/l IBA (indole-3-butyric acid) and about 65% rooted plants survived in the greenhouse. Molecular [Randomly amplified polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR)] analyses were used to determine the genetic variability of the meristems of oryzalin-treated plants. Six out of 20 RAPD primers and five out of 12 ISSR primers revealed polymorphisms (30.5 and 61.8%, respectively) among the in vitro plants indicating the efficiency of oryzalin to induce in vitro variability in hybrid rose and to detect variation through molecular markers. A comparative morphological analysis between the control and the mutant was done, which showed minor variations in some morphological characters (plant height, number of branches, foliage size, thorn density, flower diameter, flower depth, number of petals. Our findings will provide fundamental insight into an improved rose breeding program.
Mukundan Sampath, Sathyanarayana Bangalore Narayanappa, Suresh Narayanrao Sondur (India), Luke Simon (UK/India) Analysis of Genetic Diversity among Jasminum sambac (Linn.) Ait. and J. grandiflorum Linn. Varieties using Morphological and Molecular Markers (pp 60-64)
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Original Research Paper: In the present study, genetic relationships among eight varieties of Jasminum sambac (Linn.) Ait. and two varieties of J. grandiflorum Linn., collected from Southern India were compared by their morphological characters and RAPD (Randomly Amplified Polymorphic DNA) profiles. The morphological data was obtained for their vegetative and reproductive characters. PCR-amplifiable DNA was isolated using the CTAB method and 120 amplified fragments were obtained using 8 random primers. The genetic dissimilarity matrix was calculated based on Squared Euclidian Distances, which revealed a maximum genetic distance of 83% between vars. ‘Co-2 Pitchi’ and ‘Single Mohra’, which belong to different species and the minimum genetic distance (21%) was between vars. ‘Khoya’ and ‘Khoya Large’ belonging to same species (J. sambac). The Ward’s method of cluster analysis grouped all the individuals on the dendrogram into two major clusters ‘A’ and ‘B’ at 58 linkage distances with varieties of J. sambac and J. grandiflorum, respectively. Cluster ‘A’ consisted of two varieties (‘Co-1 Pitchi’ and ‘Co-2 Pitchi’) clustered at 33 linkage distances with character differing in corolla tube length and shape, size and number of petal lobes. Cluster ‘B’ was segregated into two sub-clusters ‘B1’ and ‘B2’ at 45 linkage distance. Sub-cluster ‘B1’ was further divided into two minor clusters at 39 linkage distance with one and six varieties respectively. Sub-cluster ‘B2’ with one var. ‘Ramanathapuram Mallige’ was characterised by short plants. The present study showed moderate to high genetic diversity among the both Jasminum spp. RAPD markers combined with morphological analysis proved to be a quick, simple and significant testing method to assess genetic diversity among Jasminum spp.
Agnieszka Marasek-Ciolakowska, Malgorzata Podwyszynska (Poland) Somaclonal Variation in Long-term Micropropagated Tulips (Tulipa gesneriana L.) Determined by FISH Analysis (pp 65-72)
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Original Research Paper: A new protocol for tulip micropropagation by cyclic multiplication of adventitious shoots, in the presence of thidiazuron, was developed. True-to-type plants and somaclonal variants selected from Tulipa gesneriana cv. ‘Prominence’ plants derived from long-term in vitro cultures were analysed for karyotype rearrangements and stability of ribosomal DNA (rDNA) using fluorescence in situ hybridization (FISH). The study focused on the polymorphism of number, appearance and chromosomal localization of rDNA sites. The chromosome number in the plants of the original cultivar propagated conventionally (standard) and the somaclones equalled 2n = 2x = 24 chromosomes. The karyotypes of the standard and the micropropagated plants consisted of median, submedian and subterminal chromosomes. The difference in number of each type of chromosomes was observed in somaclones but not in the standard. In all analysed plants FISH with 5S and 45S rDNA probes identified many rDNA sites on each chromosome which provided markers for individual chromosome identification. Loci of 45S rDNA were located at telomeric positions on the long arm of the chromosomes. 5S rDNA sites were predominately located in intercalative positions on the long arms in close proximity to the centromere and in the telomeric position on the short arms. In addition, 5S rDNA loci were located intercalary on the short arm on the first pair of median chromosomes. Karyotype comparison exhibited variation in the number of 5S and 45S rDNA loci and in the size of hybridization signals both between standard ‘Prominence’ and somaclones as well as among somaclones. In conclusion, we demonstrated the usefulness of FISH karyotyping with cloned 5S and 45S rDNAs in analysis of genome re-structuring in long-term micropropagated tulips.
Mohamed Rady, Shawky Bekheet (Egypt) Effect of Temperature, Sugar and Vessel Closure on in Vitro Growth of Gypsophila paniculata (pp 73-76)
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Original Research Paper: Shoot cultures of Gypsophila paniculata L. ‘Bristol fairy’ were established on MS medium supplemented with 2.69 µM α-naphthaleneacetic acid (NAA) and 2.22 µM 6N-benzyl amino purine (BAP). After three subcultures, shoots were grown in media with different concentrations of mannitol and incubated at 25 or 5°C for 6 months. To evaluate the role of type of enclosures for culture tubes and sucrose level in the culture medium on preservation of shoot cultures of gypsophila, four different enclosures namely, polypropylene caps, cotton, one and two layers of aluminum foil were used. Shoot cultures were incubated at 25°C for 6 months. The presence of mannitol in the culture retarded growth and proliferation with highest survival rates at 4% mannitol. Relatively slower growth was observed at 5°C than at 25°C. Mannitol (4%) and incubation at 5°C can be used successfully to preserve gypsophila shoot cultures for up to 6 months or more. Moreover, the absence of sucrose in the media during preservation retarded the growth of gypsophila shoot culture in all treatments with all caps used. In contrast, the addition of high levels of sucrose (2 or 3%) improved the growth (number of proliferated shoots and shoot length) of shoot cultures and was considered the best condition for in vitro preservation. Also, polypropylene caps and two layers of foil were the best covers for the proliferation of shoot cultures. Although this study does not seek to find the appropriate conditions to preserve gypsophila plantlets, the results indicate that physical and chemical treatments affect survival percentage and growth characters. In this study, gypsophila plantlets were resistant to low temperature and water deficit conditions but sensitive to the type of closure system and carbon source.
Ravindra B. Malabadi (Canada/India), Jaime A. Teixeira da Silva (Japan), Gangadhar S. Mulgund (India) Micropropagation of Eria dalzelli (Dalz.) Lindl. through TCL in Vitro Culture (pp 77-80)
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Original Research Paper: Efficient shoot regeneration of Eria dalzelli (Dalz.) Lindl. was achieved for the first time using shoot tip transverse thin cell layers (tTCLs) and thidiazuron (TDZ). Protocorm-like bodies (PLBs) or proliferating shoot buds was observed when tTCLs of shoot tip sections were cultured on Mitra et al. (1976) basal medium supplemented with 9.08 µM TDZ. The highest percentage of PLB survival was 96%, producing healthy shoots with 2-3 leaves. Shoots rooted when cultured on the same basal medium supplemented with 11.42 µM IAA. Regenerated plantlets grew normally with a 90% survival rate. This simple protocol will be useful for large-scale propagation of E. dalzelli.
Shipla Sharma, Surinder Kumar, Jitender K. Kanwar (India) In Vitro Selection and Regeneration of Asiatic Hybrid Lily Resistant to Culture Filtrate of Phytophthora cactorum (pp 81-83)
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Original Research Paper: Callus cultures derived from bulbscale segments of asiatic lily ‘Alaska’ susceptible to Phytophthora cactorum were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing calli on growth medium containing various concentrations of culture filtrate of P. cactorum. Resistant calli obtained after two cycles (30 days/cycle) of selection were used for plant regeneration. No variation was observed in the morphological characters in the selected regenerates. 40% of the plants raised from one year-old bulbs had acquired resistance against the pathogen.
Raymond A. Cloyd (USA) Management of Fungus Gnats (Bradysia spp.) in Greenhouses and Nurseries (pp 84-89)
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Mini-Review: Fungus gnats, Bradysia spp., were not considered economic insect pests until recently when it was realized they are actually major insect pests of greenhouses and nurseries. The primary species encountered are Bradysia coprophila and B. impatiens, although other species may be found in greenhouses and nurseries. Both adults and larvae may directly and indirectly disseminate or transmit a wide-range of plant-pathogens including Botrytis cinerea, Thielaviopsis basicola, Verticillium albo-atrum, and Fusarium avenaceum. The larvae causes direct damage when feeding on plant roots or tunneling into plant crowns. The presence of high larval populations can result in significant crop losses. Certain growing media influence fungus gnat development and reproduction, and fungus gnat adults are attracted to and tend to lay eggs in growing media that are moist and microbially active. Scouting for fungus gnats is critical in order to detect populations before they reach damaging levels. This involves the use of yellow sticky cards for the adults, and potato disks for the larvae, which are laid on the surface of the growing medium. Currently, there are no thresholds to determine when to implement management strategies against fungus gnats. Fungus gnat management involves a holistic approach requiring implementation of cultural (sanitation and water management), chemical (microbial insecticides and insect growth regulators), and biological control (predatory mites, predatory beetles, and entomopathogenic nematodes) strategies. |
