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Identification of RAPD markers linked to recessive genes conferring siliqua shatter resistance in Brassica rapa
Author(s) -
Mongkolporn O.,
Kadkol G. P.,
Pang E. C. K.,
Taylor P. W. J.
Publication year - 2003
Publication title -
plant breeding
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.583
H-Index - 71
eISSN - 1439-0523
pISSN - 0179-9541
DOI - 10.1046/j.0179-9541.2003.00910.x
Subject(s) - brassica rapa , biology , bulked segregant analysis , genetics , rapd , locus (genetics) , population , canola , allele , genetic marker , gene , gene duplication , chromosome , gene mapping , botany , genetic diversity , demography , sociology
Shattering of siliquae causes significant seed loss in canola ( Brassica napus ) production worldwide. There is little genetic variation for resistance to shatter in canola and, hence, the trait has been studied in B. rapa. Previous studies have shown two randomly segregating recessive genes to be responsible for shatter resistance. Three random amplified polymorphic DNA markers were identified as being linked to shatter resistance using bulked segregant analysis in a F 3 B. rapa population. The population was derived from a cross between a shatter‐susceptible Canadian cultivar and a shatter‐resistant Indian line. Of the three markers, RAC‐3 900 and RX‐7 1000 were linked to recessive sh1 and sh2 alleles, and SAC‐20 1300 was linked to both dominant Sh1 and Sh2 alleles. The common marker for the dominant wild‐type allele for the two loci was explained to have resulted from duplication of an original locus and the associated markers through chromosome duplication and rearrangements in the process of evolution of the modern B. rapa from its progenitor that had a lower number of chromosomes. Segregation data from double heterozygous F 3 families, although limited, indicated the markers were not linked to each other and provided further evidence for the duplication hypothesis.