New broomrape races have spread quickly year after year to reach 70% of the sunflower acreage in Trakya region of Turkey. These new races were more virulent in Turkey than in other countries such as Spain and at least one more race other than F race was observed in Trakya. Some inbred lines from Trakya Agricultural Research Institute-Edirne (TARI) exhibited resistance in some parts of the region, but the sunflower hybrid PR-64-A-95 exhibited resistance in all locations. This hybrid and other resistant lines will be evaluated again in subsequent years and they will be used as a differential set for determining new broomrape races.

Broomrape (Orobanche cernua Loeffl.) is the most serious problem in sunflower production in Turkey, some East European countries and Spain. A research covering broomrape tests of sunflower hybrids in the trials based on National Sunflower Research Project was conducted in Trakya region, which holds 75% of the sunflower production in Turkey, in 2006, 2007 and 2008. Based on this project, in conditions of natural infestation, 306, 443 and 533 commercial and candidate hybrids, inbred lines, etc. were tested in 2006, 2007 and 2008, respectively. Of the tested materials, 12 in 2006, 56 in 2007 and 140 in 2008 were found to be resistant. During winter, broomrape tests continued in growth chambers and in pots, under conditions of artificial infestation. Broomrape seeds were collected from a naturally infested area in Trakya region and used to determine the reaction of developed hybrids and lines to the collected races. In this part of the study, 1752, 816 and 1389 genetic material were tested in 2006, 2007 and 2008, respectively. The tests showed that 332, 94, and 404 materials in 2006, 2007 and 2008, respectively, were resistant to the new races of broomrape used in the study.

Response of six wild sunflower genotypes including Helianthus petiolaris spp. petiolaris (E-142), Helianthus neglectus (E-017) and Helianthus annuus (E-060, E-173, E-174 and E-175) to drought stress imposed at the seedling growth stage was investigated in vivo. Plant height, number of leaves per plant, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight were determined. Results indicated that the E-175 genotype belonging to Helianthus annuus was less affected by water stress conditions as compared to the other genotypes. Helianthus petiolaris spp. petiolaris (E-142) showed the highest sensitivity and had the lowest fresh and dry masses under drought conditions. In addition, this study showed that the number of leaves and root weight were the best selection criteria to determine drought resistance at the early vegetative stage. Water losses of the resistant genotypes in their roots and shoots in drought stress conditions were more than those of the sensitive genotypes.

This present investigation was undertaken to determine some plant characters in six wild Helianthus genotypes and their test hybrids in 2007 and 2008. Helianthus petiolaris spp. petiolaris (E-142), Helianthus neglectus (E-017) and four wild Helianthus annuus (E-060, E-173, E-174 and E-175) were used as the material. The morphological characters observed in the wild Helianthus genotypes were plant height, head diameter, lateral number, number of days to 50% flowering, flowering period length, and presence of anthocyanin in the cotyledons. In the second year, test hybrids of E-017, E-142, E-173 and E-175 with the female line 2453-A were evaluated for seed yield, seed weight and some morphological traits. The results showed that plant height, head diameter and lateral number for these wild genotypes ranged from 63 to 171 cm, 2.4 to 8 cm and 43 to 324.3, respectively. The wild sunflower genotypes needed 82-105 days after emergence to reach 50% flowering and had flowering periods of 67-91 days. E-142 (Helianthus petiolaris spp. petiolaris) and its test hybrid with the female line 2453A were similarly in the early group for days to 50% flowering. E-017 (Helianthus neglectus) and its test hybrids were similarly late for days to 50% flowering. Interestingly, although E-173 had medium plant height, its test hybrid had the shortest plants.

The objectives of this study were to determine self-fertility and restoration capability of cytoplasmic male fertility of some wild sunflower genotypes. The evaluated genotypes were Helianthus petiolaris spp. petiolaris (E-142), Helianthus neglectus (E-017) and Helianthus annuus (E-060, E-173, E-174 and E-175). For hybridization, the female inbred line 2453-A was used. Results showed that self fertility ratios of wild sunflower genotypes varied between 22.4 and 66.1%. The highest level of self fertility was observed in Helianthus petiolaris spp. petiolaris (E-142), while Helianthus neglectus had the lowest values. The E-060 and E-174 genotypes did not restore cytoplasmic male sterility in the hybrids tested.