Identification Of Wheat Dwarf Germplasm And Genetic Analysis Of Dwarfing Trait

Dwarfing trait is the vital useful agronomic character in wheat high yield and super high yield breeding programs. Dwarfing genes could reduce the plant height and increase the production and the application of them in whether pure line breeding or heterosis breeding is the common strategy in modern wheat breeding programs. Thus, continually releasing dwarfing genes and creating new dwarfing germplasms are meaningful for improving wheat varieties` plant height trait. In this study, the main agronomic characters of 14 dwarf germplasm lines were preliminary identified and evaluated. The genetic foundation of dwarfing trait of SN224 and SN3895-2 was analyzed. The results were showed just as follows:(1) The main agronomic characters and GA3 reaction characters of the 14 dwarf germplasm lines were analyzed which could provide reference for their application. The specific molecular markers which were linked to Rht-B1, Rht-D1 b and Rht8 were used to detect the 14 materials. The results showed that another material could be detected the dwarfing genes expect SN224 and SN2011068-8. Shannong31504, Shannong31504-1,SNL026, SN20110306-7, SN20110342-9 and SN2011069-5 could amplified Rht-B1 b +Rht-D1 b. Shannong31505, Shannong31505-1, SNL024, SNL113 and SN20100246 could amplified Rht-B1b+Rht-D1b+Rht8192 bp.(2) SN224 as a steady 1BL · 1RS translocation line was 68.6 cm and had good comprehensive agronomic characters. The detection of specific molecular marker of 1RS indicated that 1RS had no effects on SN224 dwarfing trait. In the meantime, the specific molecular markers of Rht-B1 b, Rht-D1 b, Rht8192 bp were not amplified. The plant height was between two parents of F1 from a cross between SN224 and Huixianhong and distributed continuously and normally in F2 population. 11 QTLs which were related to plant height, ear length, panicle number per plant and kernel number per spike were detected. QPh1 B and QPh4 B, which were located in 1B and 4B respectively, could explained 30.2% of phenotypicvariation in total. The QTL in KSUM062-Xmag4284 interval in 4B contributed to decrease plant height, increase ear length and panicle number per plant.(3) The ductile stalk dwarfing plant SN3895-2 was 77.6 cm, and resisted to logging.SN3895-2 could resist to powdery mildew and had good main agronomic characters. GA3 reaction indicated this dwarfing line was insensitivity. Genetic analysis showed that the plant height trait of SN3895-2 was controlled by a incomplete dominance gene. The detected molecular marker by BSA, Xmag3635 which was linked to Rht3895-2, was located 2B and the distance between these two locus was 2.0 cM.