Modern trends in breeding and genetic improvement of sunflower varieties and hybrids at VNIIMK

Modern sunflower breeding is significantly diversified due to the different needs of agricultural production. The breeding of sunflower varieties and hybrids is carried out at V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) in all areas in demand on the market and is based on fundamental biological research. In the field of breeding for faster maturing, the following commercial cultivars were obtained: very early maturing, cv. Skormas and the three-way hybrid Achilles, early maturing cvs. Varyag and Uspekh, medium maturing cvs. Amelie, Aris and Aurus. Within the framework of breeding for immunity, eight hybrids and one variety have been produced. So at the Don experimental station (Rostov region), productive hybrids were bred, resistant to the virulent broomrape of the G race due to the presence of the Or7 gene: ‘Gorstar’, ‘Gorfild’, ‘Grant’, ‘Status’, ‘Fogor’ and the three-way hybrid Nika. On the central experimental base, the following were obtained: the mid-early hybrid Typhoon and the earlymaturing variety Platonych with resistance to common races of downy mildew and a high oil content of achenes (up to 53 %) as well as the mid-early hybrid Tayzar, which is simultaneously resistant to virulent races of broomrape and to the causative agent of downy mildew. The early maturing large-fruited sunflower variety Belochka was included in the“Russian State Register of Selection Achievements…”, and the large-fruited varieties Karavan, Konditer and Kalibr are currently undergoing state tests. The breeding use of germplasm with genes for herbicide resistance wasaccompanied by their extensive genetic study. A practical recommendation for all three alleles of the ALS gene (Imr, CLHA-Plus, Sur) was the need to create homozygous hybrids for their reliable use in appropriate production systems. For Clearfield technology, the hybrids Imidzh, Arimi and Immi have been developed; for Clearfield Plus, the hybrid Klip; and for Express Sun (or SUMO), the hybrid Surus. Klip and Surus are mid-oleic. All newly developed fertile ornamental sunflower varieties – Aurelia, Fizalia, Zhemchuzhny, Rumyanets, Agat and Mazhor – were transferred for practical use to a sterile CMS RIG basis. Thus, new achievements have been attained across the entire spectrum of modern trends in sunflower breeding

Association Mapping of Fertility Restorer Gene for CMS PET1 in Sunflower

The phenomenon of cytoplasmic male sterility (CMS), consisting in the inability to produce functional pollen due to mutations in mitochondrial genome, has been described in more than 150 plant species. With the discovery of nuclear fertility restorer (Rf) genes capable of suppressing the CMS phenotype, it became possible to use the CMS-Rf genetic systems as the basis for practical utilization of heterosis effect in various crops. Seed production of sunflower hybrids all over the world is based on the extensive use of the PET1 CMS combined with the Rf1 gene. At the same time, data on Rf1 localization, sequence, and molecular basis for the CMS PET1 type restoration of fertility remain unknown. Searching for candidate genes of the Rf1 gene has great fundamental and practical value. Therefore, in this study, association mapping of fertility restorer gene for CMS PET1 in sunflower was performed. The genome-wide association study (GWAS) results made it possible to isolate a segment 7.72 Mb in length on chromosome 13, in which 21 candidates for Rf1 fertility restorer gene were identified, including 20 pentatricopeptide repeat (PPR)family genes and one Probable aldehyde dehydrogenase gene. The results will serve as a basis for further study of the genetic nature and molecular mechanisms of pollen fertility restoration in sunflower, as well as for further intensification of sunflower breeding

Accumulation dynamics of seed tocopherols in sunflower lines with modified tocopherol levels

Sunflower (Helianthus annuus L.) seeds have a tocopherol profile dominated by alpha-tocopherol. The objective of this research was to study the dynamics of tocopherol accumulation in sunflower lines with altered total tocopherol content or tocopherol profile. Developing seeds were sampled at regular intervals in two lines with reduced and increased total tocopherol content, respectively, and six lines with modified tocopherol profiles. The line with reduced tocopherol content showed a tocopherol accumulation rate reduced by half, whereas the line with increased tocopherol content showed a tocopherol accumulation rate twofold higher than the control. In the three cases, alpha-tocopherol followed a sigmoid accumulation pattern. Modified tocopherol profiles were expressed at early stages of tocopherol accumulation. In most lines with modified profiles, tocopherol accumulation pattern differed from the alpha-tocopherol lines, with maximum tocopherol content at 18 or 21 days after flowering (DAF) that was reduced to reach a plateau from 33 or 36 DAF onward. Such a reduction was caused by continued dry matter accumulation after tocopherol accumulation ceased or slowed down. In lines with increased levels of beta-tocopherol or both gamma- and delta-tocopherol, the synthesis of beta- and delta-tocopherol started and stopped earlier than the synthesis of alpha- and gamma-tocopherol, respectively. © 2013 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.Peer Reviewe