Наследование устойчивости к расе G Orobanche cumana Wallr. в F2 и ВС1 у линии подсолнечника RGM

Abstract

One of the most harmful biotic factors influencing the stability of sunflower yields is a parasite weed – broomrape (Orobanche Cumana Wallr.). Among the different measures of this parasite control, the usage of genetic resistance is the most ecologic. Lines of the different origin resistant to a race G were developed in V.S. Pustovoit All-Russian Research Institute of Oil Crops. However, inheritance of a trait of resistance was not studied in all lines. Thus, the purpose of this work was studying the genetic control of resistance to a broomrape race G in a line RGM in F2 and BC1. 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 F1 had low middle level of broom-rape infestation. When crossing heterozygous plants F1 and a susceptible parental form of sunflower in BC1 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.