Genetic analysis of Hessian fly resistance of durum wheat lines PI59190 and CI3146
Abstract
Durum wheat (Triticum durum Desf.) has been the source of many genes that confer resistance to Hessian fly [Mayetiola destructor (Say)]. This insect pest of wheat is extremely destructive to susceptible cultivars. Host plant resistance is the most effective method of control. In the eastern U.S. biotype 'L' is virulent to all commercialized Hessian fly resistance genes in common wheat (T. aestivum L.) in this region. Screening and characterizing new sources of resistance are essential, to identify new genes that may be effective against new virulent biotypes which often occur under natural conditions. Two durum wheat introduction lines, PI59190 and CI3146, were identified as having resistance to Hessian fly biotype 'L'. The objectives of this study were to determine: (a) the number of genes of PI59190 that confer resistance to Hessian fly biotype 'L' and (b) linkage relationships between Hessian fly biotype 'L' resistance of PI59190 and the resistance gene of CI3146, and between resistance genes of PI59190 and CI3146 and genes H10, H12, H14, H16, H17, H18+, H19 and H20. Segregation analysis of backcross F2 families indicated that the Hessian fly biotype 'L' resistance of PI59190 is conditioned by one partially dominant gene. Analyses of testcross F 2 progenies showed that the resistance gene of PI59190 is closely linked with H17 (2 cM) on chromosome 5A. Analysis of testcross F2 families showed that the resistance gene of PI59190 and the resistance gene of CI3146 segregate independently. The resistance gene of PIS9190 and the resistance gene of CI3146 segregated independently of other Hessian fly resistance genes tested in this study. The new gene for resistance to Hessian fly biotype 'L' in PI59190 is designated as H28. RAPD analysis of bulk-segregant DNA from segregating backcross plants of PI59190 and D6647 generated a polymorphic fragment of 300-bp. The DNA fragment generated with OPN-19 is associated with the resistant genotypes.
Degree
Ph.D.
Advisors
Ohm, Purdue University.
Subject Area
Agronomy
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