Possibilities for genetic control of sunflower resistance to broomrape (Orobanche cumana L.) at domestic and international levels

Suncokret napada volovod (Orobanche cumana L). Glavni centri napada volovoda na suncokretu su zemlje oko Crnog Mora (Rusija, Ukrajina, Moldavija, Rumunija, Bugarska i Turska). Drugi centar gde volovod napada suncokret i nanosi značajne ekonomske štete je Španija, a treći Izrael. U predhodne dve godine volovod je pronaðen na suncokretu i u zapadnom delu Kine. Volovod je prenet u našu zemlju najverovatnije iz Bugarske ili Rumunije, gde je Orobanche cumana L. znatno ranije bio prisutan. Orobanche cumana L. je stranooplodna parazitna cvetnica i pojava novih rasa je stalno prisutna. Izvori otpornosti prema volovodu se nalaze u više divljih vrsta suncokreta, ali je najveća frekvencija gena za otpornost prema volovodu prisutna u H. tuberosus. U Evropi je dugo bila prisutna samo jedna rasa volovoda (rasa A) koju kontroliše jedan dominantni gen Or1. Polovinom 20-og veka naglo se proširila rasa B. Otpornost kod suncokreta prema rasi B kontroliše jedan dominantni gen (Or2). U drugoj polovini 20.-og veka došlo je do pojave novih rasa C (Or3), D (Or4) i rase E(Or5). Dugo godina u našoj zemlji je bila dominantno prisutna rasa B prema kojoj su otporne ruske sorte i novosadski hibridi. Pred kraj 20-og veka kod nas se takoðe proširila rasa E (Bačka i Banat). Prema rasi E su otporni hibridi Bačvanin i Perun i velik broj novih inbred linija.The sunflower is attacked by broomrape (Orobanche cumana L). The main centers of broomrape attacks against sunflower are Black Sea countries such as Russia, the Ukraine, Moldova, Romania, Bulgaria and Turkey. The second major region where broomrape attacks this crop species and causes significant economic damage is Spain, while the third is Israel. Over the last two years, broomrape infestations of sunflower have been reported in western China as well. Broomrape was most probably introduced to Serbia and Montenegro from Bulgaria or Romania, where it had been present for quite some time before that. Orobanche cumana L. is an open pollinated floriferous parasite and new races of it appear all the time. Sources of resistance to broomrape can be found in several wild sunflower species, but the greatest frequency of these genes is found in H. tuberosus. For a long time, Europe had only one broomrape race (A), resistance to which is controlled by a single dominant gene called Or1. In the mid 20th century, however, a new race (B) appeared and spread rapidly. Sunflower resistance to race B is controlled by the dominant gene Or2. In the latter part of the 20th century, several more races of this parasite appeared, namely races C (Or3), D (Or4) and E (Or5). For many years, Serbia and Montenegro was dominated by broomrape race B. Resistance to this race is present in Russian cultivars and Novi Sad hybrids. At the close of the 20th century, race E also appeared in the country and spread across the regions of Bačka and Banat. Resistance to race E exists in the hybrids Bačvanin and Perun and a large number of new inbred lines

Inheritance of some yield components in sunflower

In order to study the mode of inheritance and gene effects for seed set, autofertility and self-fertility, half diallel crosses with five divergent sunflower inbred lines were made. The effects of additive, dominant and epistatic gene effects were investigated by the generation mean analysis method related to parents and their progenies (F1, F2, BC1 and BC2). Seed set was determined by the most dominant gene effects. Additive gene effects were predominant in the inheritance of autofertility and self-fertility

Achievements of sunflower breeding at the IFVC in Novi Sad

Novi Sad breeding materials and some wild species of the genus Helianthus were used to create new genetic variability in cultivated sunflower. Our breeding program during 1997-2003 had several directions, and greenhouses and winter generations (India and Argentina) were used. Artificial infection methods were utilized to develop new Rf and B-lines with resistance to diseases. Using different genetic materials and selection methods, 1,461 new restorers (Rf) and 217 new B-lines resistant to downy mildew (race 710) were developed during the 1997-2003 period. In the same period, a number of new B-lines were also developed that had high levels of tolerance to Phomopsis, Sclerotinia and Macrophomina simultaneously. Particularly valuable are the new lines with different oil quality (high-oleic plus different tocopherols). A total of 160 Rf lines with different oil quality and 157 new B-lines were developed. Furthermore, 260 new B-lines resistant to race E of broomrape (Orobanche cumana) were developed. Another important part of the breeding program is the incorporation of tolerance towards imidazolinone-based herbicides from the wild H. annuus into elite lines (B and Rf lines) and the development of the first hybrids tolerant to this herbicide group. The development of new lines tolerant to sulfonurea is in progress

Development of sunflower hybrids with different oil quality

The cultivated sunflower (Helianthus annuus L.) is one of most important oil crops of the world. Although sunflower is primarily grown for extraction of its seed oil there is a limited production of non-oilseed sunflower types which are used in confections industry or as bird feed. The objective of this research was development of hybrids with high and stable oleic acid content and modified tocopherol composition, with high values for the two most important agronomic characters (seed yield and oil yield) and high tolerance to Phomopsis. The incorporation of the gene Ol+tph1 into these genotypes has led to the development of high-oleic hybrids with altered tocopherol profiles. Oil of these hybrids has a much longer shelf-life than standard sunflower oil. The process of incorporating the genes Ol+tph2 and Ol+tph1tph2 into highly productive sunflower genotypes is under way. The most important results of this line of research are the newly developed female lines with the oleic acid content in oil over 90% and the male lines (restorers) with an oleic acid content in the 89-93% range. Using these lines, hybrids will be developed whose oleic acid content in oil will exceed 90%

Nasleđivanje boje semena suncokreta

Za ukrštanja u cilju utvrđivanja načina nasleđivanja boje semena suncokreta odabrano je osam međusobno različitih inbred linija sa belom, belom sa crnim prugama, crnom sa belim prugama, crnom sa sivim prugama, braon sa belim prugama, sivom sa belim prugama, crnom i braon bojom semena. Na osnovu dobijenih rezultata može se zaključiti: daje bela boja semena dominantna u odnosu na sve ostale boje i da je njen način nasleđivanja monohibridan, da je šareno seme dominantno u odnosu na jednobojno seme, da je crna boja monohibridno dominantna u odnosu na braon boju, daje redosled dominantnosti šarenog semena sledeći: bela sa crnim prugama, crna sa belim prugama, crna sa sivim prugama, braon sa belim prugama i siva sa belim prugama, daje redosled dominacije osnovnih boja kod šarenog semena istovetan redosledu dominacije kod jednobojnog semena i da je šareno seme uslovljeno delovanjem najmanje dva nezavisna gena koji zavisno od konstitucije drugog roditelja daju odnose razdvajanja 3:1, 15:1,9:7

An analysis of heterotic potential for agronomically important traits in sunflower (Helianthus annuus L.)

Study of inbreeding and heterosis in sunflower has been taking place for over 80 years now. Practical application of the phenomenon of heterosis in this species began after the discovery of a suitable source of cytoplasmic male sterility in 1969 and that of restorer genes. Many authors have reported significant manifestation of heterosis for seed yield and yield components as well. Also, the mode of inheritance of agronomically important traits in the F1 and F2 generations has been thoroughly examined. Positive correlations for yield have been established between parental lines and F1 hybrids. The GCA and SCA for yield and yield components have been well studied. Solutions have been suggested on how to increase the harvest index and sink capacity as well as the contributions of individual physiological parameters in the process of yield augmentation. In order to increase heterotic effects for seed yield and oil yield and direct and indirect yield components, it is necessary to increase the genetic variability of pre-breeding materials, achieve improved efficacy at the inbreeding stage, and streamline and accelerate the process of GCA and SCA evaluation using molecular markers and other biotechnology methods in order to achieve breeding goals. Seed oil content should be increased to over 55% using recurrent selection methods. Special focus in breeding programs should be placed on the development of high-oleic hybrids (>95%) with a high genetic potential for oil yield, resistance to the dominant diseases, and wide environmental adaptability that would be used for industrial purposes (production of biodiesel, or hydrogen). In order to extent the duration of sunflower oil stability, beta, gamma and delta tocopherols should be incorporated instead of alpha ones alongside the Ol genes. The exiting genetic variability of the cultivated sunflower makes it possible to develop hybrids with a genetic potential for seed yield of over 6 t/ha and seed oil content of over 55%. Most often, however, sunflower yields obtained in large-scale commercial sunflower production are in the 1.5-3.0 t/ha range. There are multiple limiting factors preventing the realization of the high genetic potential of this crop. Their removal will enable commercial sunflower yield to stabilize at levels of 4 t/ha and above. Diseases are the main limiting factor affecting sunflower production in all sunflower-growing parts of the world. Development of exotic germplasm through further use of wild sunflower species, distant hybridization and genetic transformations should be used to provide genes for resistance to all dominant pathogens and broomrape. Efficient breeding methods should be employed to increase sunflower tolerance of air and soil drought and salinity and to attain wider resistance to herbicides

The components of genetic variability for bract length, width and number in sunflower (Helianthus annuus L.)

Half diallel crosses of four inbred sunflower lines were studied for genetic components of variance (D, H1, H2, F) for bract length, width and number in F1 and F2 generations. The analysis of variance indicated the presence significant differences between the treatments. In the heredity of bract length, width and number, the dominant components (H1 and H2) played a more important role than the additive ones (D). The dominant and recessive genes controlling the three traits were not symmetrically distributed in the parental lines. The parents had a greater number of dominant genes for bract number and of recessive genes for bract length and width. The average degree of dominance ((H1/D)1/2) and the point of intersection between the projected line of regression and the Wr axis both indicate the presence of superdominance in the heredity of the three investigated traits in F1 and F2 generations. The regression coefficient did not significantly deviate from the value of 1 for all three traits and in both generations, meaning there was no epistasis. Both broad and narrow sense heritability (h2b and h2a) were high for all traits

The use of PCR-based markers in the evaluation of resistance to downy mildew in ns-breeding material

The aim of this work was the application of previously developed and development of new PCR markers for the evaluation of sunflower resistance to downy mildew. Twenty sunflower inbred lines were investigated. Plant resistance to downy mildew was determined by the whole seedling immersion method. Genomic DNA was extracted from the first pair of leaves, and its polymorphism was investigated by RAPD, SSR and several published markers for disease resistance. The presence of the markers Ha-NBS 7/R, Ha-NBS 8/R Ha-NBS 9/R, in Pl6 donor lines (Ha-335, JM-8) and in resistant progeny (Ha-26, G12, G10, G11) confirm that HAP3 could be useful for the detection of the Pl6 gene. DNA polymorphism, which coincided with disease resistance, was revealed with one RAPD (UBC 119 fragment 900-1000 bp) and one SSR primer (ORS37 fragment 600-700 bp). Amplified fragments segregated in the same way i.e., they appeared in 50% of the resistant genotypes. The non-expecting SSR fragment was purified, cloned and sequenced. The results indicated that this fragment is not a part of a coding sequence. Specific primers for the amplification of this fragment have been designed and the investigation of the inheritance of this SCAR marker is under way. None of the applied markers appeared in all resistant genotypes. In order to select lines for making crosses for use in further investigation, the obtained results were also used for the calculation of genetic distances between genotypes (simple matching coefficient) and the construction of a dendrogram (UPGMA method)