جستجوی مقالات مرتبط با کلیدواژه "نماتد سیستی" در نشریات گروه "گیاهپزشکی"

Heterodera schachtii, the sugar beet cyst nematode (BCN), is a limiting factor in most of the beet-growing regions of Iran. Considering this disease's importance and spread, generating resistant cultivars is one of the most important methods to reduce its damage. Achieving accurate and fast resistance assessment methods facilitates the development of resistant cultivars. This research aims to compare the response of twenty domestic and foreign sugar beet genotypes to BCN under greenhouse conditions and with the presence of the MN3 molecular marker, which is linked to the BCN resistance gene. Analysis of variance showed a significant difference among genotypes for resistance to BCN in greenhouse conditions. Using the MN3 molecular marker and greenhouse survey, no susceptible plants were observed in genotype No. F- 21238. Hybrids No. 34781 and 34791 demonstrated the highest resistance (80 and 78% of plants were resistant) under greenhouse conditions and good resistance (80 and 89% of plants were resistant) to this pathogen evaluating the MN3 marker. The results showed that to save time and more accuracy in selecting resistant genotypes, it is better to evaluate genotypes with MN3 molecular marker, and then the chosen genotypes are assessed to determine the level of resistance to this pathogen in greenhouse conditions.

Sugar beet is adaptable to be cultivated in different weather conditions and regions. In 2015, the overall area for sugar beet cultivation was estimated about 105,000 hectares which 19000 of this was in Khorasan Razavi province. Sugar beet is considered as a valuable agricultural crop both for economy and employment. Nevertheless, producing this crop faces many challenges including the high number of pests. One of these pathogenic factors is the nematodes. Among plant-parasitic nematodes cyst nematodes are a large group with economic importance in different countries. These nematodes cause much damage to agricultural crops. Among the different cyst nematode genera Globodera and Heterodera have species which are important due to economic damage.

During the year of 2016, 22 samples of soil and roots of sugar beet in cyst nematodes contaminated field in Khorasan Razavi were gathered. Cyst nematodes were extracted by the use of a small clip and a binocular and put in petri dish with some water. White materials were also taken from the root by a delicate needle and put in sterile distilled water after washing. Separating and purifying fungi were done in 3 parts: separating fungi from cysts and materials, separating fungi from eggs and larvae nematode, and making single spore fungi and pure culture. The cysts and separated materials were washed by distilled water for several times and antisepticised for 1, 2 or 3 minutes in 10% Sodium Hypochlorite, and 10% and 20% Ethyl alcohol. Cysts and materials were washed again with sterile distilled water and sterile sifter was used. The cysts and materials in petri dish containing PCA, PDA, CMA and MEA culture mediums were separately taken and cultured by a needle under laminar. Four cysts were placed at the 4 sides of each 8cm petri dish containing the above mentioned culture mediums. 16 brown cysts from each soil sample were cultured. Two petri dishes from each sample were kept and checked consistently in two hot and cold temperatures in incubator with 20-25 and incubator with 8-10. After 7-14 days the grown fungi were taken to a new culture medium of PDA for a better development and in later stages they were purified on WA culture medium by single spore or hyphal tip methods. Purified fungi were kept in test tubes containing PCA food environment and 4 temperature and also on sand for later studies. Cyst shells were destructed by cyst crusher (homogenizer) and their eggs and mash were released. Released eggs from cysts were formed into suspension in sterile water. 0.5-1 ml of suspension of eggs and larvae were taken by sterile micropipette and diffused on petri dish containing water agar culture medium. These culture mediums were kept and checked regularly in dark in the incubator with 20-25. Grown fungi from these eggs and larvae were taken to a new culture medium and purified by single spore and hyphal tip methods. WA culture medium was used for single spurring and purifying fungi. PCR based methods morphological and molecular identification, were used to identify the fungi isolates. Mycelium fungi growth phases, fungi DNA extraction, PCR reaction and electrophoresis were done to identify molecular fungi. Lipase and chitinase assays were performed on the isolates.

For Lipase test, each fungal isolate was cultured on peptone agar media and after 7 days isolates were examined. Around the colony of the isolates produced by the lipase enzyme formed a precipitate or a colorless aura, which is due to the formation of calcium salts from free lauric acid by the lipase enzyme, which indicates the positive activity of lipase. Among the isolates, Colletotrichum gloeosporioides had the highest sediment content, indicating the activity of lipase enzyme and the highest isolate in this test. After that, Neonectria macrodidyma and Penicillium chrysogenum showed the highest activity of lipase enzyme activity. Fusarium oxysporum showed no sediment and the lowest level of lipase enzyme activity was observed in this fungus. For chitinase test, isolates were cultured on colitic kitein medium. Around the colony and also the color of the culture medium, the chitinase-producing isolates changed the violet color, which indicates the positive activity of the chitinase enzyme in these isolates. Relative analysis of chitinase activity showed that the isolate of P. chrysogenum had the largest and fastest change in color to violet, indicating the highest production of chitinase enzyme by this fungus. The lowest chitinase production was by C. gloeosporioides, which showed the slightest and slowest changes in color compared with other isolates and the weakest isolate was introduced for the production of chitinase enzyme.

In this research, different fungi were isolated from sugar beet cystc. Most fungal isolates belonged to Torbat-e-Haidiriyah and Fariman, and the least isolates belonged to Khaf. The highest frequency of Fusarium isolates was found to be 37.35%. Isolation of Simplicillium lanosoniveum fungi, P. chrysogenum, C. gloeosporioides was the first reported cyst nematode in sugar beet. In the relative analysis of lipase activity, it was found that P. chrysogenum and C. gloeosporioides fungi exhibited the highest amount of lipase production, which was the highest marker in this test. Relative analysis of chitinase activity showed that P. chrysogenum had the largest and fastest color change to purple, indicating the highest production of chitinase enzyme by this fungus. The lowest chitinase production was obtained by isolate C. gloeosporioides, which showed the slightest and slowest changes in color compared with other isolates. The fungus P. chrysogenum showed the best results in both tests, this fungus is, therefore, recommended for further research with the observation of the necessary points.

Effect of Organic Manure on Sugar Beet Cyst Nematode Population Densities of Heterodera schachtii Schmidt 1871
Introduction. Sugar beet cyst nematode (SBCN), Hederodera schachtii Schmidt. 1871, marked as one of the most damaging disease of sugar beet worldwide. It's also an important disease of sugar beet in Isfahan Province, and causing plenty of an irreversible damage. Thus, the nematode infested fields for cultivation in the province and the country is to be threatened. This nematode has a wide host range, over 218 plant species from 95 genera, belonging to 23 families, including field crops, ornamentals and weeds as hosts, which have been identified and introduced so far. The SBCN management's strategies are a long term crop rotation, use of catch crops, early planting and the use of nematicides. In general, the best method reported to control SBCN is a 3 to 7-year rotation with non-host plants. In addition, incorporation of farm manure into the soil had a positive effect in controlling potato golden cyst nematode. Testing on vermicomposting and non-organic fertilizers revealed that, free-living nematodes in the population index were highest in the vermicompost treatments than non-organic fertilizers.
Materials and methods. The initial population of SBCN in the infested soil was determined, before the treatment of the selected field. Then, 200 g. of soil were selected, out of several samples collected from every plots, which was air dried and in the file system using Fenwick, the cysts were extracted. Eggs and the second larvae in the soil and end up in a 200 g. of soil were calculated accordingly. All the organic matters, including, poultry manure at 10, 20 and 40 t/ha compost fertilizer by municipality of Isfahan wastes, vermicompost, waste cabbage leaves and farm manure (cow manure) were employed. Reproductive factors and the percent decrease and or increase in SBCN populations in each treatment were calculated relative to the initial population of the same treatment. And, comparison of means was done by Duncan tests. For the Greenhouse experiments, the same treated soils from each and every treatment in field were poured into the clay pots with a capacity of 5 kg of soil. At the time of harvest, the produced beets in each and every plot were weighted, and the beet samples for determining of sugar percentage and the important elements were sent to sugar factory for analyzes. The analysis of variance was performed, using SAS software and comparison method.
Results and ddiscussions. The initial population of SBCN was 4.85 eggs and larvae per gram of soil, before the implication of the treatments in the field. There were 92.40 and 88.44 percent reduction in SBCN final population for the poultry manure at the rate of 40 and 20 tons per hectare, with the high significant effect, in comparison to other ones respectively. Variance analysis of Reproduction factor showed that there is a significant difference between the treatments. Poultry manure 40 t/h with 0.14 eggs and larvae per gram of soil was the lowest one in reproduction factor, with a high significant effect to other treatments and control groups. Followed by poultry manure 20 t/h, compost 015, 60 ha, poultry manure 10 t/h and compost 08, 60 t/h, in the next category with a significant effect. The results on the yield, sugar content and other indices showed significant differences between the various treatments. Poultry manure 20 and 40 t/h, with the yield of 27.55 and 26.93 t/h, in a statistical group had the maximum amount of product with a very minor difference, were the most effective treatments on the assessed factors, including final population, reproduction, multiplication rat and reduction percentage in SBCN, H. schachtii compared to other treatments and the checks. In this regard, it has been shown on other nematodes that, chicken manure has reduced the population of M. incognita, Hoplolaimus columbus and Pratylenchus penetrans in brinjal. And also the use of chicken manure on control of root-knot nematodes was very effective and even caused IGR in tomato production.
Conclusion.1- It was found that, the use of organic matters, chicken manure, municipal compost, vermicompost; waste cabbage leaves and farm manure in different amounts control the SBCN population accordingly.
2- Therefore, it is suggested here, that chicken manure at 20t/ha, is for an optimum use and economically reasonable and significant amount for the SBCN control.
3- Also composts 015 and 08, vermicompost, farm manure and waste cabbage leaf at 40 to 60t/h, in terms of economic value appears to be applicable.
4- Always a method or a substance, in terms of its own hazards is not recommended. Therefore, any of the said material can be used in intervals for SBCN control and or in integration with other methods such as crop rotation, disease scape,