Development of aneuploids by means of doubled haploid technology- corn pollination method

Development of aneuploids in wheat is traditionally conducted through crossing and backcrossing, followed by selfing for several generations to produce genetically stable progeny. The objective of this study was to develop aneuploids in wheat using the established maize- pollen based doubled haploid (DH) technology. A cross of 08-47-50/Crocus was made in 2011. Crocus is a wheat line (AABBDD) with three crossability genes (kr1kr2kr3), while 08-47-50 is a partial amphiploid (AABBEE) with resistance to leaf rust, stem rust, powdery mildew and Fusarium head blight (FHB). F1 plants were used for producing doubled haploids. Two hundred and eighty eight embryos were recovered from 15,186 florets pollinated with corn pollen. Thirty-two plantlets were obtained from these embryos. Finally, eight stable doubled haploid lines were obtained with chromosome numbers ranging from 42 to 48. The results of disease evaluation showed that the line DH-Cro50-5 was resistant to FHB and that the line DH-Cro50-7 was highly resistant to powdery mildew. The remaining lines were resistant to leaf rust, stripe rust and/or Ug99 stem rust races. Chromosome characterization of these DH lines was conducted using in situ hybridization techniques. Preliminary results revealed that the line DH Cro50-2 had 42 chromosomes with a terminal translocation. The results of this study indicate that application of DH technology can save considerable time in the development of aneuploids in wheat compared to traditional methods. The resistant aneuplod lines developed using the DH method can be used directly as new sources of resistance in wheat breeding programs for improvement of FHB, powdery mildew, leaf rust and stem rust resistance.