Xu Xiang¹ , Zhan'ao Deng² , Qifa Zheng³ , Cunxian Chen³ , Frederick G. Gmitter Jr.³

1. Institute of Fruit Tree Research, GDAAS, Guangzhou, 510640
2. University of Florida, GCREC, Bradenton, FL34203, USA
3. University of Florida, CREC, Lake Alfred, FL33850, USA
Author    Correspondence author
Bioscience Methods, 2010, Vol. 1, No. 1   doi: 10.5376/bm.2010.01.0001
Received: 13 Oct., 2010    Accepted: 24 Nov., 2010    Published: 30 Nov., 2010

This article was first published in Molecular Plant Breeding (Regular Print Version), and here was authorized to redistribute under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Xu et al 2009, Developing Specific Markers and Improving Genetic Mapping for a Major Locus Tyr1 of Citrus Nematode Resistance, Molecular Plant Breeding, 7(3): 497-504

The NBS-LRR class resistance-gene candidate sequences (Pt8a and Pt9a) were used to develop new specific markers to the citrus nematode resistance gene locus Tyr1. By high-density colony screening, over 200 positive clones were pulled out from the BAC library. A few of the clones were found to be closely linked with the Tyr1 region, because the primers from these clones insert sequence produced polymorphism which matched up with the phenotype after bulked segregant analysis. By primer walking approach, three integrate NBS-LRR class resistance-gene sequences were tagged and identified separately in three clones (7A4, 4L17 and 29F20). More specific markers were developed from these tagged sequences and relatively high-density genetic maps were constructed by incorporating the newly developed markers and previously developed markers in the ‘9145 family’. New markers were applied in ‘9401 family’ trying to estimate roughly the genetic distance between the Ctv and Tyr1 region.

Citrus; Nematode; Resistance gene; Molecular marker; Genetic map