Lesion Mimic Phenomenon Correlation Analysis With Agronomic Traits And Quantitative Trait Loci Positioning In Common Wheat (Tirticum Aestivum L)

Disease is one of the key elements for controlling the high and stable production ofwheat. Exploration of disease resistance genes and breeding resistant cultivars areconsidered as an effective method to control the diseases. Disease resistance is divided intovertical resistance and horizontal resistance; disease physical races have been rapidlydifferentiated with the changes of environment, its harmful to wheat yield growing. Someresearchers have proved that majority lesion mimic were related to horizontal resistance.The lesion mimic phenomenon has occurred in rice, corn, wheat, peanut and other crops,but few studies were reported in wheat. The material we used in the study, parents and F1generation plants showed normal phenotype, but the phenotypes were separated in the F2generation plants, become which appear as normal and lesion mimic two phenotypes. Anin-depth study on the lesion mimic, not only can reduce or avoid the loss of production, butalso lay the foundation for the mining and location of resistance genes, deepen ourunderstanding of plant defense system and mechanism of programmed cell death, enrichplant molecular pathology and molecular biology meaning. This study is a research onwheat lesion mimic phenomenon; the results were shown as follows:1."Anti-256×stone4185" combinations lesion mimic phenomenon belongs torecombinant lesion, correlation analysis with other agronomic traits, results showed thatlesion mimic and panicle length, panicle number and grain weight was correlated.2Through the test material identification and genetic analysis, we found that theparents and F1generation did not show lesion mimic phenomena, which begins to show F2generation. In each of generation, normal plants and lesion mimic plants ratio close to3:1,The recombinant inbred lines was established by single-seed descent, it is speculated thatlesion mimic phenomenon is controlled by major genes, which participate in and modifiergenes. According to the results of QTL location, the QTL that come from kang256wasnamed LM3, QTL from the stone4185genes were called LM4and LM5, using the SSRmarkers made three genes on the4D chromosome. LM3is located betweenXgwm213-Rht-D1b, at genetic distances from Xgwm21314.3cM, explained26.16%phenotypic variation, the additive effect-0.48; LM4was located between Wmc617and Barc91, at genetic distances from Wmc6170.99cM, explained11.60%of the phenotypicvariation, the additive effect was0.32; LM5is located between Rht-D1b-Wmc818, atgenetic distances from Wmc81811.3cM, explained26.45%phenotypic variation, theadditive effect of-0.48, control lesion mimic trait QTL cumulative explained phenotypicvariation rate of64.2%.3In the LOD=5threshold of lesion mimic for epistatic interaction detection, a total of25pairs, including only1pair of major QTL x QTL interaction,10major QTL xminor-effect loci (Minor-QTL) and14Minor-QTL x Minor-QTL. Minor loci’s interactionsare the largest proportion in all interaction occupies, it also influences the yield traits.4In this study, all the lesion mimic QTL locis were located on the4D chromosome(the fifth linkage groups), and the characters has involved certain correlations. Minor lociof other traits are also enriched in this region, indicating that the region may existpleiotropism phenomenon or the QTL locis are closely linked.