Research Notes : Canada : Linkage tests

Volume 14 Article 15 4-1-1987 Research Notes : Canada : Linkage tests R. I. Buzzell Agriculture Canada Reid G. Palmer United States Department of Agriculture Follow this and additional works at: http://lib.dr.iastate.edu/soybeangenetics Part of the Agriculture Commons, Agronomy and Crop Sciences Commons, and the Plant Breeding and Genetics Commons Recommended Citation Buzzell, R. I. and Palmer, Reid G. (1987) "Research Notes : Canada : Linkage tests," Soybean Genetics Newsletter: Vol. 14 , Article 15. Available at: http://lib.dr.iastate.edu/soybeangenetics/vol14/iss1/15 This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Soybean Genetics Newsletter by an authorized editor of Iowa State University Digital Repository. For more information, please contact . 77 AGRICULTURE CANADA Research Station Harrow , Ontario , CANADA 1) Canada NOR 160 Linkage tests. Results repo rted by Buzzell (1974) were not conclusive as to whether or not E3 (daylength r esponse) and Ep (seed coat peroxidase) are independent or loosely linked. Palmer et al. (1984) has shown that Ep is l inked with Frl in linkage group 12. Using F 2 plants of ' Minsoy ' x 'Hark ' previously reported (Palmer et al ., 1984) for seedcoat peroxidase and root fluorescence, we tested for linkage of E3 with Ep and Frl by testing F3 material for response under a daylength extended to 20 h with cool white fluorescent light . In addition, the material was evaluated for resistant (Rmd)/susceptible (rmd) reaction to powdery mildew . 'Blackhawk ' carries the eJ and Rmd alleles and Hark the E3 and rmd alleles. Both Blackhawk and Minsoy are early flowering and resistant to mildew. Therefore, an allelism test was made by crossing Blackhawk x Minsoy. For daylength response, there were 122 flowering plants and no nonflowering plants; for powdery mildew reaction there were 92 resistant plants and no susceptible plants . Minsoy appears to carry the same e3 and Rmd alleles as Blackhawk . Results (Table 1) indicate that the EJ and Rmd are not linked with Ep and Frl in linkage group 12. E3 and Rmd may be loosely linked, however ; further evaluations will be done to test whether or not these genes are linked or are independent. Table 1. Results of F2 linkage tests+ Number of F2 plants Genes a b c d %R Sum SE Phase++ Minsoy (ep frl e3 Rmd) x Hark (Ep Frl E3 rmd) E3 e3 Ep ep 207 50 67 13 337 53 .0 4.2 E3 e3 Frl frl 205 51 59 21 336 45 . 0 3.9 c c EJ e3 Rmd rmd 177 53 50 7 287 39.3 4.9 R Ep ep Rmd rmd 184 50 45 8 287 I R Fr 1 fr l Rmd rmd 183 42 46 16 287 I R Harosoy (fg3 Pc) x L63-1097 (Fg3 pc) Fg3 fg3 Pc pc 36 13 15 4 68 +Product method, Immer and Henderson (1943). ++c = Coupling; R = Repulsion . 45.8 9.5 R 78 Buzzell and Palmer (1985) reported that Fg3 and pc might be closely linked. The ' Harosoy' isoline L63-1097 was crossed to Harosoy ; the presence of Fg3/fg3 was determined by thin layer chromatography by using leaf samples of Fz plants and the presence of Pc/pc (pubescence type) was determined by using Fz plants and confirmed by F3 tests grown in the greenhouse. Results (Table 1) indicate that the presence of Fg3 in L63-1097 after five backcrosses for pc is a chance occurrence and not the result of a close linkage . References Buzzell , R. I. 1974 . Soybean linkage tests . Soybean Genet . Newsl . 1: 11- 14 . Buzzell, R. I . and R. G. Palmer . bean Genet . Newsl . 12: 32-33 . 1985. Soybean linkage group 1 tests . Immer, F. R. and M. T. Henderson . Genetics 28 : 419- 440 . 1943 . Linkage studies in barley . Palmer, R. G. , S. L. Broich and X. Delannay. bean Genet . Newsl . 11 :97-99. 1984. Linkage Group 12 . R. I . Buzzell R. G. Palmer - USDA Soy- Soy-  (...truncated)