Plant Height And Lodging Resistance Research Of New Wheat Germplasm N0381D

In recent years,lodging has been the major factor to limit high and stable yields of wheat. And reducing plant height is the most effective measure to improve lodging esistance. Especially in the 20th century later, dwarf and semi-dwarf varieties were planted widely in the world, and wheat yield was significantly improved. The dwarf genes and Lodging-resistance cultivation have become a major path for high-yield and sup-high yield breeding. However, dwarf wheat breeding was depended on the discovery of the dwarf germplasm and dwarf genes. At present, the genetic base of dwarf wheat breeding was narrow due to most of the dwarf varieties were from Norin10 and Akagomugi. Therefore, it is important for wheat breeding that keeping on creating, discovering new dwarfing sources ,enriching their diversity and widespread application.Dwarfing traits investigation, GA3 raction identification and molecular technique have been carried out in N0381D which was created from the N9738 and GaoYou 503.The location of the dwarfing gene using molecular markers is studied simultaneously.The results are showed as follows:1 In the survey of agronomic traits investigation, N0381D have good field characters with dwarf (52.00cm), mid-early maturity , strong lodging-resistance characteristics and kernel white, cutin.And presents that Epidemic of wheat stripe rust and powdery mildew mixed race were highly resistant strains.Therewill be some value in wheat genetic improvement.2 F1 and F2 hybrids were created by crossing between the dwarfing germplasm N0381D and high material Abbondanza.By Genetic analysis , the height of the plants of F1 were close to the value of medium parents. The results were showed that the proportion of the dwarf and high individuals in the F2 segregating population was 123:33, the segregation ratio fitted the expected 3:1. And the proportion of the dwarf and semi-dwarf in the BC1 population was 39:36 the segregation ratio fitted the expected 3:1.In a word the dwarfing character of N0381D was controlled by a major recessive gene and minor genes. 3 The seedlings of N0381D and Abb were sprayed on the different concentration GA3. we found that the height of the seedlings of Abb become considerably higher, and the blade is yellow, leaf droop , but the height of the seedlings of N0381D was still invariant, and green leaves, strong. Accordingly, the dwarfing gene is insensitive to GA3.4 BSA (Bulked Segregating Analysis) was used for molecular analysis with 125 individuals of F2 population. SSR marker Xwmc503 was identified. The linkage analysis and the calculation of the map distance were conducted with JionMap4. Marker Xwmc503 was linked to this dwarf gene with genetic distance 19.3cM. The genetic map was drawn with the software Mapdraw.5 The SSR marker Xwmc503 which was linked to this dwarfing gene was located on chromosome 2DL by using the Chinese Spring nullisomic-tetrasomics and ditelosomics. We speculated that this gene was located on chromosome 2DL .At present, because none of dwarf genes had been located in 2DL. We speculated that the dwarf gene of N0381D was a new dwarf gene, named RhtN0381D.6 Compared with the plant height of Abb, the height of the plants of F1 reduced 22.80%. So the dwarf gene is a moderate intensity dwarfing gene. The drop culm intensity is of advantage to lodging resistance. And plant height is moderate, and up to the mustard of cultivation.There were good ventilation and light condition in the group of new germplasm.It is important to increase the biological yield of wheat and production.