Inheritance of Cercospora Leaf Spot Resistance in Hybrids of Monogerm Dihaploid Sugar Beet Lines

G. KIKINDONOV and Tz. KIKINDONOV
Agricultural Institute, BG- 9700 Shumen, Bulgaria

Abstract

KIKINDONOV, G. and Tz. KIKINDONOV, 2004. Inheritance of Cercospora leaf spot resistance in hybrids of monogerm dihaploid sugar beet lines. Bulg. J. Agric. Sci., 10: 39-42

The inclusion of obtained via in vitro gynogenesis dihaploid lines in the breeding program of sugar beet imposes the study of the inheritance of the basic economic characters, including the resistance to diseases, in their hybrids.
On the basis of Cercospora leaf spot resistance ratings of monogerm dihaploid lines and their hybrids with multigerm dihaploid and tetraploid pollinators the inheritance of the resistance to the disease's agent has been determined.
The lower resistance of the monogerm dihaploid lines dominates in their hybrids with multigerm dihaploid pollinators, as well as in the triploid hybrids with the multigerm pollinator 43a3.
The mean rating of the triploid hybrids' resistance is an indication for an intermediate inheritance of this character, but the various inheritance in the separate crosses is indicative for the complex mechanism of interaction between the genetic systems of the pathogen and the host.
The higher resistance of one of the parents is inherited overdominantly in the crosses with the tetraploid pollinator 46Rc, and incomplete dominance of the Cercospora resistance factors of the pollinator 985R is the typical way of inheritance in its hybrids.

Key words: sugar beet, Cercospora, dihaploids, resistance, inheritance
Abbreviations: Dh - dihaploid (doubled haploid), MS - male-sterile