Influence of seeds microflora on commercially valuable traits of the parental lines and hybrids of sunflower of VNIIMK’S breeding

The presence of seed infection in seeds of 19 B-lines, 15 Rf-lines and seven hybrids of sunflower of VNIIMK breeding were studied in VNIIMK in 20102011, 2014. The Naumova’s method (1960) was used to estimate seed infections by fungi and bacteria. The researches showed pathogens of alternariosis and bacteriosis to be presented generally on sunflower seeds. The presence of Alternaria infections varied in average from 0 to 26% in the most resistant maternal lines (SL01 3828, SL05 4038, SL01 3839). Affection of seeds of the most susceptible lines (VK 678, VK 867) was due to years from 26 to 99%. The percentage of the bacteriosis pathogens observed on the seeds of the maternal lines was in average for three years from 0.7% at line SL01 3869 to 17.3% at line VK 869. Affection by alternariosis of paternal lines seeds was in average for three years from 2 (line VK 585) to 36.7% (line VD 541), of paternal one-head line BK 541 - 63.7%. The variations depending on the year conditions were from 0 to 4% at line VK 585 and from 0 to 12% at line VK 554 which are the most resistant to Alternaria pathogen; the variations at the most susceptible lines VK 552, VK 789, BD 541 were from 33.7 to 36.7%. Bacteriosis infections on seeds at the same period were from 0.7 (line VD 541) to 27.0% (line RHA 398). For hybrids seed infection by Alternaria was from 4 (Hermes) to 42.5% (Prizyor) in average for three years. Variations due to years were from 0 to 8% (Hermes) and from 12 to 73% (Prizyor). Seed infection by bacteriosis at this period was from 4.0 (Avangard) to 33.0% (Yupiter). The small amounts of other pathogens (Rhizopus spp., Fusarium spp., Phomopsis spp., and seed molding) were observed periodically. Increased level of precipitations during period of maturity and harvesting causes enlarging of quantity of seeds infected by alternariosis and bacteriosis pathogens. The average positive dependence between 1000 sunflower seed weight and its infection by alternaria species was estimated. For hybrids this rate was r = 0.584, for maternal lines r = 0.598. The high positive correlation between seed infection by Alternaria species and sunflower hybrid seed falls was observed. There was not found out any dependence between a degree of seed infection by bacteriosis and studied traits. The maternal lines SL01 3828, SL05 4038, SL01 3839 and paternal lines VK 585, VK 554, Si-2 which has insignificant presence of alternariosis can be recommended for the further usage in breeding works.