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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #146341
Title: INHERITANCE OF RESISTANCE TO SCLEROTINIA HEAD ROT IN SUNFLOWER

Author
item VAN BECELAERE, GUILLERMO - NORTH DAKOTA STATE UNIV.
item Miller, Jerry

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 2/12/2003
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sunflower head rot, incited by Sclerotinia sclerotiorum, is one of the major diseases affecting this crop. Devastating losses have occurred since 1992 when the major production area of sunflower has received above average moisture and humidity conditions during the growing season. The objective of this study was to determine the general combining ability (GCA) and specific combining ability (SCA) effects of different sunflower inbred lines for resistance to head rot. Both oilseed and confection studies were conducted in three environments. Plants were artificially inoculated with a suspension of ascospores and incidence was measured. In general, confection hybrids and lines were more susceptible to head rot than oilseed hybrids. Additive gene action was relatively more important than nonadditive gene action in the expression of resistance. The GCA of the male and female lines were significant for the oilseed hybrids, with the female lines being more important. These results suggest that resistance is required in both the female and male lines to create a resistant hybrid, and that the lines should be tested in specific hybrid combinations.

Technical Abstract: Sunflower head rot, incited by Sclerotinia sclerotiorum, is one of the major diseases affecting this crop. Devastating losses have occurred since 1992 when the major production area of sunflower has received above average moisture and humidity conditions during the growing season. The objective of this study was to determine the general combining ability (GCA) and specific combining ability (SCA) effects of different sunflower inbred lines for resistance to head rot. Both oilseed and confection studies were conducted in three environments. Plants were artificially inoculated with a suspension of ascospores and incidence was measured. In general, confection hybrids and lines were more susceptible to head rot than oilseed hybrids. Additive gene action was relatively more important than nonadditive gene action in the expression of resistance. The GCA of the male and female lines were significant for the oilseed hybrids, with the female lines being more important. These results suggest that resistance is required in both the female and male lines to create a resistant hybrid, and that the lines should be tested in specific hybrid combinations.