Inheritance of resistance to race G of Orobanche cumana Wallr. in F2 and BC1 in sunflower line RGM

One of the most harmful biotic aactors influencing the stability of sunflower yields is a parasite weed - broomrape (Orobanche Cumana Wallr.), Among the digferent measurer of this parssite csnteol, tire ussge of genetic resistance is the most ecologic. Lines of the different origin resistant to a race G were developed in V.S. Pustsvoit All-Russian Rese arch institute of OilCrops. However, inheritance of a hah ot iesietance was not studied is all lines. Thus, the Surpose of this work was studying tire genstic control of resistance to a broomrape race G in a line RGM in F2 and BCi. To analyze inheritance, we used the line RGM resistant to the broomrape race G and susceptible to this race the sterile and fertile forms of a line VK 680 of VNIIMK breeding. Resistance of plants in F2 and BC1 was tested in protected ground infected with seeds of a broomrape race G using a method of earlier diagnosis by A.Ya. Panchenko. Reciprocal crosses of the line RGM and susceptible sunflower lines resulted that all obtained hybrids Fi had low middle level of broomrape infestation. When crossing heterozygous plants Fi and a susceptible parental form of sunflower in BCi two phenotypes were obtained: susceptible and incomplete resistant (intermediate) in the ratio of 1 : 1. This is typical for monogenic inheritance of a trait. A value x2 was equal 1.38 that certifies the hypothesis the only gen controls resistance of this line with a probability from 0.20 to 0.30. In F2 population splitting for three phenotypical classes was observed: resistant, intermediate, and susceptible in the ratio of 1 : 2 : 1. A value x2 was equal 0.58 that certifies the hypothesis the only gen controls resistance of the studied line with an incomplete dominance with a probability from 0.20 to 0.30.