جستجوی مقالات مرتبط با کلیدواژه "gladiolus" در نشریات گروه "گیاهپزشکی"

Bulb mites of genus Rhizoglyphus (Acari: Acaridae) have been identified as pest of many crops in storage, greenhouse, and field. The most important hosts are species of family Liliaceae (e.g. Allium spp.) Rhizoglyphus echinopus (Fumouze & Robin) (Astigmata: Acaridae) is one of the most important pest of gladiolus corms in Mahallat. The mites infest bulbs and corms by penetrating through the basal plate or outer skin layers. Bulb mites may establish in the inner layers, which makes control extremely difficult. Feeding wounds created by bulb mites provide entry sites for soil-borne fungal pathogens such as pythium, rhizoctonia and fusarium. Despite their economic importance and broad distribution, the control of R. echinopus remains in a state of confusion and needs a thorough evaluation. In addition, the field biology and ecology of this mite is not well studied, and methods for sampling, monitoring and assessment are limited. Management of bulb mites is complicated because of their short generation time, high reproductive potential, broad food niche, interactions with other pests and pathogens, and unique adaptations for dispersal. Historically, these pests have been controlled by synthetic acaricides and insecticides, which are now limited due to their resistance. Alternative control strategies, including cultural and biological control, have shown limited success, but need to be further developed and implemented. We evaluated the capacity of the soil-dwelling predatory mite, Hypoaspis (Geolaelaps) aculeifer (Canestrini) (Mesostigmata: Laelapidae), as well as disinfestations of corms to control attacking bulbs mite. The experiment was performed in 24 treatments and 3 replicates in randomized complete block design. Each plot was separated with plastic and its soil was sterilized by solarization. In addition, 30 gladiolus corms were cultivated in each plot. Disinfestations treatments (corms were soaked in poison solution for 25 minute) include: 1, 2 & 3- abamectin (0.4, 0.8, 1.2 ml/lit); 4, 5 & 6- ethion (1, 1.5, 2 ml/lit); 7, 8 & 9- fenazaquin (0.5, 1, 1.5 ml/lit); 10, 11 & 12- hot water (45°C for 25, 50 and 75 min); 13, 14 & 15- release of predator mite H. (Gaeolaelaps) aculeifer 10, 20 and 30 predator for every 100 Gladiolus bulb (previously infested with bulb mites); 16, 17 & 18- release of 100, 250 and 500 predator mites in square meter 15 days after planting; 19, 20 & 21- tap water as control treatments (30°C for 25, 50 and 75 min); 22- hot water (45°C for 25 min) and release 10 predator for every 100 gladiolus bulb; 23- hot water (45°C for 25 min) and release of 100 predator mites per square meter; 24- hot water (45°C for 25 min) and release 10 predator for every 100 gladiolus bulb and release of 100 predator mites per square meter 15 day after planting. Significant differences were found among treatments and with control (α= 0.5). In all cases, the population of predatory mites increased as long as bulb mite densities were not too low. Experiments in the greenhouse showed that in the absence of predatory mite, populations of the bulb mite, R. echinopus, on gladiolus corms increased, whereas population growth of bulb mite was slowed down as the predatory mite were released. The highest infestation severity was observed in treatments 19, 20 and 21 (control), while the lowest percentage of corms infestation were recorded in treatments 24, 23 and 22. The highest frequency of corms was produced in treatment 24, also the highest inflorescence length was found in treatments 13 and 24. The height length mean of gladiolus stem was observed in treatments 24, 23 and 13, respectively. The flowers in treatments 7, 14, 17 and 23 lived the greatest. The fastest germination rate was recorded in corms in treatments 24, 23, 22, 14, 15, 13 and 10, respectively. But the number of buds was statistically located in the same group and their differences were not significant. Based on the results and with respect to the gladiolus features, biological and integrated pest control methods could be recommended for reducing R. echinopus infestation.

Gladiolus belongs to the family Iridiaceae. It is commercially cultivated in all parts of the world. This plant is mainly affected by wilt disease caused by Fusarium oxysporum Schlecht Fr f .sp. gladioli (Massey) Snyd. and Hans. It results in death of plant and rotting of corms. Fusarium disease of gladiolus is commonly known as yellows, wilt or corm rot. The wilt disease of gladiolus is known to occur in almost all gladiolus growing areas. Wilt disease is one of limiting factors of cultivation and development of gladiolus in Jiroft, Kerman, Iran. Different fungi such as Fusarium oxysporum f.sp. gladioli, F. moniliforme, F. sporotrichiella, F. hetrosporium and Penicillium gladioli, P. rubrum have been reported as causal agents of gladiolus wilt, root and corm rot disease in many countries. The disease symptoms, including yellowing of leaves, weakness of plant, flower imperfect, root and corm rot, browning of infected root and corm, wilting and finally death of infected plants which observed in infected samples. No research has been carried out in Jiroft, therefore, this research aims to study and identify the causal agent of wilt disease on gladiolus.
During survey, characteristic symptoms of wilt disease were recorded and also samples were collected for isolation of pathogens that infect on Gladiolus. The infected corms showing typical symptoms of wilt disease were used for the isolation of pathogen. The standard tissue isolation procedure was followed to isolate the pathogen. To identify the causal agent of gladiolus wilt, infected tissues from symptomatic plants were first surface disinfestations, dehydrated and cultured on Potato Dextrose Agar Medium and incubated at 25± 2oc. Isolated fungi identified using morphological and microscopic characters. To pathogenicity test, corms were inoculated using the dip method in conidial suspension and then planted in pots containing sterilized soil. Inoculated plants were checked for disease symptoms. Distilled water used for inoculation of plants as a control. Observations were made regularly for the appearance and development of symptoms. After symptom development, re-isolation was done from the artificially infected corms.
The disease symptoms, including yellowing of leaves, weakness of plant, flower imperfect, root and corm rot, browning of infected root and corm, wilting and finally death of infected plants observed in infected samples. The type of disease symptoms was similar to others which have been reported before. A fungus with white aerial mycelium and little dense colony recovered from infected cultured samples. The produced micro conidia were single, sometimes two cells, oval to ellipsoid in shape, in diameter 3.75-5 * 8-10 micrometer which formed on single and short phialides. Macroconodia were mostly 3-4 celled, in diameter 3-5 * 18-35 micrometer and formed on spordochia. Chlamidospores were spherical to round shape, mostly single, sometimes in the short chain and formed intercalary and terminal. 10 to 14 days after inoculation the symptoms of the disease were seen as yellowing, plant weakness, and wilt. Based on morphological and pathogenicity test, the isolated fungus identified as Fusarium oxysporum f. sp. gladioli and confirmed by the Iranian Research Institute of Plant Protection. Infantino and Rumine (1993) reported that the F. oxysporum f .sp. gladioli infected other members of the Iridiaceae family. Other Fusarium species associated with the corms of gladiolus are Fusarium solani (Mart) Sacc., Fusarium subglutinans (Woolenweb and Reinking) Fusarium heterosporum. Nees ex Fr and Fusarium sporotichoides Sherb. ( Georgieva and Peikova, 1976). This is the first report of Fusarium wilt of Gladiolus on three different cultivar (White, pink and red) in Jiroft, located in the south part of Kerman, Iran. Few resistant cultivars are available in the world. It found that Australian fair and Monsoer were tolerant to F. oxysporum. f .sp. gladioli.
based on this research project, the causal agents of gladiolus wilt disease in Jiroft is Fusarium oxysporum f. sp. gladioli. Disease incidence was different on three gladiolus cultivars which cultivated in this area. Field observation showed, the white cultivar was more tolerant in comparing to red and pink gladiolus cultivars. In gladiolus wilt disease control managements, more emphasis should be focused on disease resistance. The more resistant cultivars should be tested for resistance to several Fos isolates.

During 2008-2009، a total of 154 gladiolus (Gladiolus grandiflorus) corms were collected from the distribution centers in Karaj (Iran). After cultivation، fresh leaf samples of all germinated corms were tested by DAS-ELISA، which revealed the infection of 74. 02% of plants with Bean yellow mosaic virus (BYMV). Following biological purification of an isolate، designated as BYMV-GPK، its host range was determined. The molecular mass of BYMV-GPK coat protein was estimated as 34 KDa by SDS-PAGE، which was confirmed by western blot analysis. DAS-ELISA and tissue print immunoassay (TPIA) techniques showed similar sensitivity in detection of BYMV in leaf tissue of infected gladiolus plants، but none of them was able to detect BYMV in corm tissue of the same infected plants. Two fragments of GPK genome، corresponding to HC-Pro and 3´ end regions with 600 and 1100 bp in length، respectively، were amplified by RT-PCR. Phylogenetic analysis based on the nucleotide and deduced amino acid sequence of HC-Pro and genomic 3´ end region showed that BYMV isolates clustered into separate groups according to their host origin and GPK isolate was closely related to a trifolium and other gladiolus isolates.