abstract
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The rapid evolution of the pathogen and the emergence of new virulent races, makes the sustainable control of wheat stripe rust a very challenging task. Pyramiding of adult-plant resistance genes (APR) is an important way to increase durability of resistance, whereas the examples of the successful use of such pyramids in the traditional sense have been less reported. Using marker-assisted selection, we developed wheat lines with pyramiding of APR genes Yr18, Yr36 and YrAS2388R for durable resistance. The transferring of these three Yr genes into elite wheat cultivars Shumai 969 and Shumai 830 showed improvement of resistance to stripe rust, while no yield penalty. These three genes were introgressed into a susceptible wheat line SY95-71 genetic background to develop BC3F5 lines with different gene combinations. Field resistance tests indicated that deployment of APR genes could improve the resistance of SY95-71. The resistance level of single Yr gene in SY95-71 was YrAS2388R > Yr18 >Yr36. The resistance levels of different Yr genes combinations in SY95-71 were Yr18+YrAS2388R+Yr36 > YrAS2388R+Yr36 > Yr18+Yr36 > Yr18+YrAS2388R. The two-gene pyramid (YrAS2388R+Yr36) and the three-gene pyramid (Yr18+YrAS2388R+Yr36) showed high level of stripe rust resistance. The resultant pyramided lines are expected to be used as improved germplasms/varieties for durable resistance breeding.