Submitted to: Helia
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/3/2002
Publication Date: 7/1/2002
Citation: PEREZ-VICH, B., AKHTOUCH, B., MUNOZ-RUZ, J., FERNANDEZ-MARTINEZ, J.M., JAN, C.C. INHERITANCE OF RESISTANCE TO A HIGHLY VIRULENT RACE "F" OF OROBANCHE CUMANA WALLR. IN A SUNFLOWER LINE DERIVED FROM INTERSPECIFIC AMPHIPLOIDS. HELIA. 2002. V. 25 (36). P. 137-144. Interpretive Summary: Sunflower broomrape is a parasitic angiosperm, totally devoid of chlorophyll, that infects the roots of sunflower plants drawing water and nutrients from them. This parasitic plant is one of the most important constraints on sunflower production in areas of eastern and southern Europe, the Middle East, Russia, Ukraine and China. The most economical and effective means of controlling sunflower broomrape is the use of resistant cultivars. However, recent studies have shown appearance of a new sunflower broomrape race in Spain, designated as F, overcoming all the resistance genes identified so far. New resistance source has been introduced into cultivated sunflower from wild perennial Helianthus species and released as four germplasm populations, BR1 to BR4, in 2001. The objective of this study was to determine the inheritance of resistance to broomrape race F in material derived from BR4. A simple on-gene control of the resistance was observed, which will graetly simplify the sunflower breeding for resistance to this new race of broomrape.
Technical Abstract: Broomrape (Orobanche cumana Wallr.) populations belonging to a new race F in Spain have overcome all known resistance genes Or1 to Or5 in cultivated sunflower (Helianthus annuus L.) and are spreading rapidly. Resistance to race F of this parasitic weed has been found in wild perennial species of Helianthus and has been introgressed into cultivated sunflower. The objective of this study was to characterize the inheritance of resistance genes in cultivated sunflower derived from wild perennial species H. divaricatus and H grossesserratus, respectively. Crosses between resistant cultivated lines and the susceptible line P21 were made, and most of the F1's were resistant when evaluated for broomrape resistance using a highly virulent population of race F indicating dominance reaction of resistance genes. Evaluation for resistance of segregating populations of F2 and BC1F1 to both parents confirmed in some of the crosses the dominance reaction of the F1. This dominance reaction of resistance genes will greatly simplify the breeding procedure for resistance.