Two different sunflower lines with increased beta-tocopherol concentra tion in the seeds, LG-15 and T589, have been developed. The objective of the present research was to conduct a comparative genetic study of the increased beta-tocopherol concentration in both lines. Plants of LG-15 were reciprocally crossed with plants of T589 in 2003. The F1, F2, BC to LG-15 and BC to T589 seed generations were produced in the same environment in 2004 and analyzed for tocopherol profile. The results indicated a strong environmental effect on the increased levels of beta-tocopherol concentration in LG-15 and T589, which averaged 30.5% and 25.8%, respectively, in 2003 and 43.2% and 54.0%, respectively, in 2004. The comparison of individual plant means and standard errors of individual plant means for the F2 and BC generations with those in the non-segregating parental and F1 generations indicated no transgressive segregation for beta-tocopherol concentration in F2 or BC seeds. These results suggested that increased beta-tocopherol concentration in both lines is the result of genetic alterations at the same locus.

Sunflower (Helianthus annuus L.) being a cross-pollinated crop, genetic adulteration is a vested problem and varietal description is cumbersome. An investigation was carried out using sunflower hybrids, their parental lines and open pollinated varieties to identify and establish phylogenetic relationships among genotypes and characterize them based on both morphometric traits and PCR based RAPD markers. Data on twelve quantitative traits and thirty two quantitative traits were analyzed. Data for 5 primers were used to establish genetic distance and construct dendrograms using statistical software package. Based on the analysis of clustering of sunflower genotypes it was found that morphometric traits were not in accordance with the molecular markers. At the molecular level, 25 scorable bands were produced with the 5 primers with the number of bands ranging from 3 for OPH-15 to 9 for OPG-10. Of the 25 bands, 14 were polymorphic (58.11%). A male specific third fragment amplified by the primer OPI-16 was inherited by the hybrid KBSH-1 and the primer OPH-15 failed to amplify DNA from all the varieties except Morden.

Analysis of microsatellite sequences was used for estimation of genetic diversity of cultivated and wild sunflower and usefulness for genotype identification, genetic purity and “hybridity range” definition. In total 13 SSRs were tested. Unique alleles for some wild sunflower species were found. Eight out of 13 SSR loci were polymorphic for the investigated inbred lines. Four of the investigated microsatellites are suitable and sufficient for genome identification and determination of parentage of hybrids. A procedure is proposed for sunflower genotype registration based on DNA-typing.

The direct organogenesis method in immature F1 hybrid embryos from sunflower, used for the first time in this study, was successfully applied for production of new forms from the intergeneric cross Helianthus annuus (cv. Albena) × Verbesina helianthoides (genus Verbesina). A large number of new sunflower lines were produced after self-pollination and individual selection. Agronomic traits such as oil content in seed, 1000-seed weight, leaf width, leaf length, number of leaves, length of petiole, internode length, head diameter, stem diameter, diameter of branch head, number of branches, length of branches, number of ray florets, seed width, seed length and seed thickness were investigated. After characterization of the hybrid progenies according to the above indices, the conclusion can be drawn that lines 131 R, 138 R, 140 R, 143 R and 144 R show 76.5% intermediate phenotype in comparison with the two parental forms. Some of the new restorer lines were successfully used in heterosis breeding of sunflower. The positive change was 35.3% and the nega tive change was 11.8%. Line 140 R is of positive breeding importance because it exhibited an oil value exceeding the cultural and wild parents by 2.9 and 24.6%, respectively.

The method of direct organogenesis has been successfully used for overcoming the inability for crossing between Helianthus annuus (cv. Albena) and Verbesina helianthoides (genus Verbesina). As a result of long-term individual selection in the hybrid materials, fertility restorer lines were produced in the R 10 generation. The applied molecular method (RAPD) confirmed the hybrid nature of the obtained breeding material and indicated an introgression of Verbesina helianthoides DNA into some of the hybrid progenies produced. Using the similarity coefficient of Nei and Li (1979), a dendrogram was generated through UPGMA analysis with the aim to determine the genetic distance of the studied genotypes. We were able to demonstrate that RAPD could be used for characterization of intergeneric hybrid progenies in sunflower at a late stage of selection (F9) in which an increased genetic variation was discovered.

Cotyledons, roots, hypocotyls and immature germs of sunflower hybrids have been tested for morphogenesis. High morphogenetic ability was revealed in the cotyledon explants, hypocotyls and immature germs. Explants of hybrids Poglad, Kiy and Svitoch showed the best ability for morphogenesis. The obtained shoots were rooted for development of complete plants. The effect of "premature flowering” was discovered in all cases.

A new sunflower (Helianthus annuus L.) dwarf line, HA-ARG-1, has been developed after interspecific hybridization between cultivated sunflower H. annuus and wild annual silver-leaf sunflower H. argophyllus. Plants were selected for reduced height and multiple branching characteristics. The agronomic, morphologic and oil content characteristics of the line were analyzed. Isolation of similar dwarfed lines illustrates the importance of using the wild sunflower germplasms in the development of specific plant material which can be used in sunflower breeding and hybrid development programs.

A new unified nomenclature system of downy mildew races was intro duced in 2000 (Tourvieille et al., 2000). The present study has the aim to determine the distribution and race composition of sunflower downy mildew in Bulgaria according to this new nomenclature. During 2000-2003, 57 samples were collected from infected plants and their race affiliation was determined. According to the results obtained, three downy mildew races were isolated during this period: races 100, 300 and 700. Race 100 had the most limited distribution, 3.5% of the downy mildew population. It was detected only during the first year of the investigation. Race 300 was isolated during all years of study. Its percent in the pathogen population was 36.8% averaged for the period. It was distributed mainly in the southeastern, northwestern and central parts of Bulgaria. Race 700 had the widest distribution during the period of investigation. It was isolated from 34 out of a total of 57 samples analyzed, which was 59.7%. Its area of distribution was mainly in northeastern Bulgaria.

Seed treatment with phenylamide fungicides (metalaxyl and mefenoxam) provides an effective chemical control of sunflower downy mildew caused by the oomycete Plasmopara halstedii. Resistance of the fungus to metalaxyl has been reported in Spain and differences of disease incidence (DI) caused by field populations (FPs) have been observed. The sensitivity of several FPs to seed treatment with metalaxyl was compared. Different groups of FPs were discriminated on the basis of DI caused on sunflower plants. None of the FPs was completely controlled by the fungicide at the dose used. In addition, the efficacy of metalaxyl and mefenoxam against FPs resistant to metalaxyl were evaluated. Three genotypes of sunflower were treated with the fungicides at two different doses. Neither metalaxyl or mefenoxam nor doses had a significant effect on the DI caused by the FPs, suggesting the absence of effect of the double quan tity of active enantiomer provided by mefenoxam as compared with metalaxyl. Nevertheless, significant differences on DI were observed among genotypes. The different DIs could be related to: a) different germination rates and, consequently, size of the radicle in the moment of inoculation, b) higher amount of fungicide provided to the confectionery genotype, which has a larger size of seed.

In the present investigation, two fungicides viz. Bavistin and Dithane M-45 were tested for the effect on soil mycoflora with special reference to mycorrhizal fungi of sunflower crop. It was evident from the results that the two fungicides had different effects on soil mycoflora. Reduction of various species of soil fungi was more extensive in first twenty days in comparison with the later half of the experimental period. The fungicidal effect of both fungicides decreased with increase of time and it resulted in reappearance of certain fungi after a certain period of time. Regarding the effect of fungicides on sunflower growth and phosphorus content, it was found that as the concentration of the fungicides increased, the growth decreased and minimum growth was observed in 1% concentration of Bavistin as well as of Dithane M-45. Both fungicides had deleterious effect on mycorrhizal spore number and percentage mycorrhizal root colonization.

Alternaria blight in sunflower, caused by the fungus Alternaria helianthi, is one of the major diseases that affects sunflower in Brazil. The effect of this organism on net photosynthetic rate of four sunflower genotypes was measured under field experimental conditions. Through a mathematical approach the diseased leaf area and net photosynthetic rate were related and used to analyze the pathosystem sunflower/Alternaria. An average decrease in the photosynthetic rate was observed in diseased leaves for all analyzed genotypes in comparison with healthy leaves. Alternaria blight reduces photosynthesis not only through a reduction in green leaf area, but also through an effect on photosynthesis of the remaining green leaf tissue. Leaves free of the pathogen lesions in diseased plants present also a photosynthetic reduction.

This paper summarizes the results of infection level evaluation for the most harmful sunflower diseases in Central Chernozem Region of Russia. Using annual and perennial wild sunflower species from collection as sources of resistance to pathogens has shown to be important. Various forms of cultivated sunflower have been obtained during many years work. Among them, we identified male and female sunflower lines with complex resistance. These lines also possess high general combining ability and agronomically important traits. A disease causing several extremely located necrotic spots has been regis tered at the end of the growing season. This kind of disease development may be considered as field resistance index.

This investigation was conducted in order to determine the degree of biochemical changes during accelerated and natural aging of sunflower seed. Five sunflower lines developed in Novi Sad, submitted to accelerated aging for three and five days, and natural aging of six and twelve months under conventional storage and controlled conditions, were used in these trials. Malondialdehyde, superoxide dismutase contents and peroxidase activities were studied. Lipid peroxidation and superoxide dismutase and peroxidase activities (especially pronounced in accelerated aging variant) were caused by both types of aging. The degree of seed damage and the ability of seed to resist the negative conse quences of aging were influenced, beside duration of aging period, by type of storage and characteristics of sunflower lines.

The aim of storage is to preserve properties of products and their fresh ness. If suitable storage conditions aren’t supplied according to product variety, quality and quantity losses increase. Decreasing this losses is possible with providing suitable storage condition and storage management. In this study, sunflower storage buildings in the Thrace Region were examined. Influences of storage condition on product losses were investigated. The study was conducted in one of the Thrace Union’s reinforced concrete store, temporary store and a model store having aeration system built specificly for this research in Tekirdag Agricultural Faculty’s area. Temperature and relative humidity of the sunflower mass as storage conditions in the stores and moisture content, oil content and free fatty acids contents as quality parameters were monitored during the storage. According to the results of experiments in selected stores, the worst storage conditions and the most qual ity losses were determined in the concrete store, on the other hand the most suitable conditions and the least losses were determined in model store.

A two-year field study was carried out in a Mediterranean environment (Foggia, Southern Italy) to assess the effects of two soil tillage depths (conventional and minimum tillage) and three strategies of nitrogen (N) fertilization (organic, mixed, mineral) on the growth, biometric parameters, yielding and qualitative characteristics of sunflower cropped with durum wheat in a two year rotation. The fertilizer treatments applied were: 100com, with Municipal Solid Waste (MSW) compost; 100mix, with organic N (MSW compost) and min eral N; 100slow, with a slow release organic-mineral fertilizer; 100min and 50min, with mineral N; unfertilized control (Contr). The results obtained during the trial period have shown that the minimum soil tillage, MSW compost fertilization (as 100com and 100mix) and conservative practices were able to give good quantitative and qualitative responses. Furthermore, no increase of heavy metals has been found in the plots treated with MSW compost application.

A field trial was conducted in Pindi Bhattian area on sandy loam soil (EC 4.85 dSm-1; pH 7.95; hydraulic conductivity 3.92 cm h-1; bulk density 1.42 g cm-3) to evaluate the growth performance of ten commercially cultivated sunflower genotypes under saline conditions. Ten sunflower genotypes were sown in plots (2.25 m x 15 m) according to a randomized complete block design (RCBD) in three replicates keeping the line-to-line distance of 75 cm and the plant-to-plant distance of 30 cm. The P2O5 (60 kg ha-1) and K2O (100 kg ha-1) fertilizers were applied as SSP and SOP, respectively, at the time of sowing, while N (60 kg ha-1) was applied in two equal splits (one half at sowing time and the other half at first irrigation). Five plants from each plot were randomly selected at maturity to get data on plant height (cm), shoot fresh weight (g), head fresh weight (g), and head diameter (cm). The upper fully matured leaves along with petiole (each from five plants) were collected for leaf area (cm2). Sodium, K, Ca and Mg were analyzed in digested samples using an atomic absorption spectrophotometer. Maximum shoot fresh weights by DK-3915, PARSUN-1 and CRN-1435 closely followed by PARC-9707 were 695.9, 682.3, 669.9 and 578.4 g per plant, respectively. Head fresh weights were highest in CRN-1435, 6451 and DK-3915. The cultivar 6451 produced a comparatively low shoot fresh weight but was significantly (p<0.0001) superior in seed yield (2475 kg ha-1) that was 47% higher than the maximum shoot biomass producing variety DK-3915. The cultivars CRN-1435 and HU-777 were also among the highest seed yielding genotypes. K+ concentrations in leaves, petiole and stem of the genotype Super-25 and cultivar 6451 were maximum compared with the other genotypes. Generally, the cultivars having high concentration of K+ main tained a low concentration of Na+ in its leaves. The high potassium concentra tions in leaves, petioles and stems suppressed the detrimental effect of Na+ ions on 1000-grain weight and percentage of oil. High Ca2+ concentrations were observed in leaves, petioles and stems of PARC-9707 and PARC-9706.