Creating sunflower lines with group resistance to diseases

Abstract

Nineteen lines-restorers of pollen fertility with low affection by the Phomopsis pathogen and resistance to sunflower downy mildew were selected by hybridization techniques and repeated individual selections on the field and laboratory infectious backgrounds.Purpose. To create new sunflower lines with group resistance to disease agents, to determine their donor properties by this trait for the introduction into breeding programs.Material and Methods. The studies were conducted over the period of 2007-2013 on the field and laboratory infectious backgrounds in the Infection Nursery of Scientific Crop Rotation of the Plant Production Institute nd. a V. Ya. Yuryev of NAAS. After crossing 15 paternal and 7 maternal sterile lines, which were alternative by resistance to Phomopsis, 16 lines conditionally resistant were selected of 41 hybrid combinations using a laboratory rapid assessment on detached leaves. A cycle of self-pollination was founded on these lines to create line material resistant to Phomopsis. Annual assessments of the resistance of inbred generations to the Phomopsis pathogen were carried out on the provocative background; annual assessments of the resistance of inbred generations to the downy mildew pathogen starting with constant generations І6 - І8 were performed under laboratory conditions in winter.Results and Discussion. The influence of meteorological conditions on the level of Phomopsis infectious background was analyzed. As a result of many years’ selections 19 sunflower lines (BI 5 V - BI 51 V) were created, with one or many calathiums, high degree of pollen fertility restitution (100%), various plant height (77.1 - 116.0 cm) and duration of the growing period from germination to flowering (40 - 57 days), having lodging- and drought-resistance. Stabilization of resistance to the Phomopsis pathogen in genotypes in І3 – І7 was performed on the provocative background. Their resistance to the Phomopsis pathogen is confirmed by a low level of disease development under the conditions of the epiphytotic year of 2013. Based on the assessment results, all the 19 lines are immune to race 4 (730) of downy mildew, i.e., they are carriers of genes Pl- 6 and Pl- 8. Four of them (BI 7 V - BI 10 V) are donors of resistance to this disease.Conclusions. During 2007 - 2013 19 lines with group resistance to diseases, lodging and drought were created from hybrid combinations by individual selections using rapid assessments for the Phomopsis and downy mildew pathogens. Under the conditions of epiphytotic development of Phomopsis in 2013, these lines confirmed their endurance to Phomopsis affection, and their lesion level did not exceed the average.