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Stagonospora nodorum blotch (SNB), caused by Phaeosphaeria nodorum, is one of the most devastating foliar diseases on wheat (Triticum aestivum L.) in the northern Great Plains of North America. This study was conducted, under controlled environmental conditions, to elucidate the genetics and map the resistance to SNB caused by spore inoculum and culture filtrate of P. nodorum isolate Sn2000. A hard red spring wheat population was developed from a cross between the susceptible cultivar Steele-ND and the resistant line ND 735 for this study. Two-leaf seedlings of the parents, F1 and F2 generations, and F2:6 recombinant-inbred lines (RILs) were inoculated with spore suspensions while independent two week old seedlings of segregating generations were infiltrated with culture filtrate. Disease reaction was assessed 8 days after inoculation based on a lesion-type scale while plants were evaluated for culture filtrate response four days after infiltration for the presence or absence of necrosis. Genetic analysis revealed that a single recessive gene, Tsn1, in ND 735 confers resistance to both spore suspension and culture filtrate of P. nodorum isolate Sn2000. Mapping analysis using Diversity Arrays Technology (DArT) and simple sequence repeat (SSR) markers indicates the gene, Tsn1, is located on the long arm of chromosome 5B and is flanked by the DArt markers wPt-8285 and wPt-3049 at a distance of 7.0 cM and 2.9 cM, respectively. This gene also controls resistance to tan spot caused by Pyrenophora tritici-repentis race 2. Results of this study reveal that wheat-P. nodorum interaction follows the toxin model of gene-for-gene hypothesis. Additionally, the finding of single gene control in the line ND 735 for both tan spot and SNB enhances the utility of the line ND 735 in wheat breeding program as a source of multiple disease resistance. 相似文献
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Samaneh Saberi Kazem Zendehdel Sahar Jahangiri Yeganeh Talebkhan Afshin Abdirad Nazanin Mohajerani Maryam Bababeik Najmeh Karami Maryam Esmaili Akbar Oghalaie Parisa Hassanpour Neda Amini Mohammad Ali Mohagheghi Mahmoud Eshagh Hossieni Marjan Mohammadi 《Iranian Biomedical Journal》2012,16(4):179-184
Background
Attempts for early detection of gastric cancer have recently focused on host''s genetic susceptibility factors and gene-environment interactions. We have, herein, studied the association of MTHFR C677T single nucleotide polymorphism (SNP) and its interaction with Helicobacter pylori infection, smoking, age and gender on the risk of gastric cancer among an Iranian population.Methods
Gastric cancer patients (n = 450) and cancer-free controls (n = 780) were studied for serum H. pylori-specific IgG antibodies by ELISA and MTHFR C677T polymorphism (SNP) by PCR-RFLP. Demographic and life style data were collected through patient interviews. Unconditional logistic regression model estimated odds ratio (OR) and the corresponding 95% confidence intervals (CI).Results
The interactions of MTHFR genotype with H. pylori infection (P = 0.03), age (P = 0.049) and gender (P = 0.007) were statistically significant. Accordingly, MTHFR C677T carriers who were also positive for H. pylori infection exhibited 80% (OR = 1.8, 95% CI = 1.0-2.9) significant excess risk of non-cardia gastric cancer. Furthermore, subjects over the age of 50 or female subjects carrying MTHFR C677T SNP showed 40 (OR = 1.4, 95% CI = 1.0-2.0) and 100 (OR = 2.0, 95% CI = 1.2-3.2) percent increased risk of gastric cancer, respectively.Conclusion
MTHFR C677T SNP seems to increase the risk of gastric cancer and the effect is significantly inflated by interactions with H. pylori infection, age and gender. Key Words: Helicobacter pylori, Smoking, Gender identity, Age group, Methylenetetrahydrofolate reductase 相似文献14.
Ghavami S Amin GA Taghizadeh M Karimian Z 《Pakistan journal of biological sciences: PJBS》2008,11(2):181-187
In the present study, density of abundance of spiders explored and dominant species determined in the cotton major fields i.e., Ardebil, Fars, Golestan and Tehran provinces in 2003-2004. Through regular weekly, specimens collected by shaking bushes and they were carried out for the further study to the Araneae laboratory. A total of 632 specimens were classified in 76 species, 59 genera belonged to 19 families. Twenty seven species and 15 genera of them were new records for spider's fauna of Iran. The collected spiders counted and frequency of each species and dominant species determined. The following species Thanatus formicinus (Clerck), Cheiracanthium pennyi (O.P. Cambridge), Aulonia albimana (Walckenaer), Neoscona adianta (Walckenaer) were dominant species in Tehran, Ardebil, Fars and Golestan cotton fields, respectively. 相似文献