The cultural characteristics and histochemical variations following infection with Alternaria helianthi was studied in six wild Helianthus species of three ploidy levels (diploid, tetraploid and hexaploid) possessing different degrees of resistance to the pathogen and in cultivated sunflower (H. annuus cv. CO-4, susceptible check). Of these, the species H. occidentalis and H. tuberosus were found to be highly resistant while H. hirsutus was moderately resistant. Media supplemented with leaf extracts of wild species, with the exception of H. grosseserratus, supported less growth and sporulation of A. helianthi than media supplemented with leaf extract of cultivated sunflower. Reduced infectivity of the pathogen was recorded when grown on leaf extract media of H. occidentalis, H. hirsutus and H. tuberosus. Furthermore, abnormalities in the shape of conidia were noticed on supplemented media with leaf extracts of H. occidentalis and H. tuberosus. RAPD analysis of the fungal DNA isolated from the pathogen grown on leaf extract media of cultivated and wild Helianthus species revealed no polymorphism. Histochemical studies showed restriction of the pathogen to epidermal cells in resistant wild sunflowers as well as an increased accumulation of phenols.

The biochemical basis of resistance to the leaf spot/blight pathogen A. helianthi was compared in six wild Helianthus species, possessing three ploidy levels (diploid, tetraploid and hexaploid) and different degrees of resistance to A. helianthi, and cultivated sunflower (H. annuus cv. CO-4, susceptible check) in terms of sugar, phenols and isozymes of peroxidase, polyphenol oxidase and chitinase. The resistant species of wild sunflowers (H. tuberosus, H. occidentalis) possessed higher levels of constitutive as well as induced total phenols and total sugars as compare with cultivated sunflower and susceptible wild sunflowers. Polyacrylamide gel electrophoretic (PAGE) isozyme analysis of defence-related enzymes showed a positive correlation of resistance with chitinase and polyphenol oxidase and a negative correlation with peroxidase.

Leaf spot disease caused by Alternaria helianthi (Hansf.) is an important fungal disease of sunflower in India and elsewhere. Non-availability of known sources for resistance to Alternaria is a major constraint in sunflower breed ing. Hence, seeds of sunflower genotypes were subjected to gamma-irradiation to develop mutant populations. Mutants were selected from the M2 generation based on percent disease incidence and were passed on to the M3 generation. Genomic DNA from leaf samples was evaluated by PCR amplification using random decamer primers and the amplified DNA fragments from mutants were compared with their respective controls. Single marker and stepwise regression analysis carried out in relation to percent disease index indicate that the alleles OPC5-B, K, J, OPA12-D and OPA15-A are strongly associated with Alternaria helianthi resistance.

Experiments have been conducted at Institute of Oilseed Crops, UAAS, Ukraine, to study the usefulness of electrophoresis of seed storage proteins in defining genetic purity of sunflower seed material. They have shown it is possible to use albumin markers for genetic homogeneity definition of sunflower parent lines and hybrids.

A new sunflower (H. annuus) introgression line HA-VERB, selected for its considerable earliness of blooming, is described in this paper. The line has been developed after intergeneric hybridization between cultivated sunflower H. annuus L. and Verbesina encelioides (Cav.) B. & H. var. exauriculata Rob. & Greenm. Plants are polycephalic (multiple branched), with reduced plant height. The agronomic and morphological characteristics of the line HA-VERB are reported. The development of inbred line with reduced blooming date appears to be an obvious advantage for increasing the range of potential uses of sunflower genotypes as donors in plant breeding.

In this paper we describe an intergeneric hybrid between H. annuus (HA 89) and T. rotundifolia obtained by normal pollination of a male-sterile cultivated sunflower. The hybrid had a combination of morphological traits from both parents; it was unbranched and exhibited male-sterility. The plant did not produce viable achenes when pollinated with HA 89. DNA fingerprinting through the AFLP methodology exhibited 240 polymorphisms and confirmed the hybrid nature of the experimental plant. The genetic distance analysis discounted the phenomenon of partial hybridization.

In Mozambique, there exist large differences in soil and climatic conditions, but it is the particular farming system (a subsistence type) that princi pally justifies the use of varieties on which this program of sunflower genetic improvement focuses. The present the program involved the selection of a series of experimental populations with different characteristics. Comparative tests were performed at the experiment station of the Instituto Nacional de Investigação Agronómica (INIA) in Umbeluzi (Mozambique). The different susceptibilities to rust (Puccinia helianthi) and charcoal rot (Sclerotium bataticola), by which it is possible to distinguish the different synthetics, are discussed in relation to the different source material and to the possibilities of performing new cycles of recurrent selection.

Increasing seed and oil yields is the top priority of most sunflower breeding programs. Getting benefit from use of heterosis is the main purpose in sunflower hybrid breeding. The objectives of this study were to determine performance of sunflower varieties and to measure the vigor of sunflower hybrids. In 2000 and 2001, sunflower hybrids were evaluated for four important yield components, yield performance, standard and regular heterosis, and heterobeltiosis, in Edirne - Turkey conditions. Based on observations in this research, seed yield of hybrids was changed between 37 and 245 kg ha-1, oil yield between 17.6 and 118.8 kg ha-1, oil content between 38.0 and 50.8% and hull rate between 19.2 and 27.1%. The highest heterosis (288.3%) and heter obeltiosis (98%) were found for oil yield. The highest standard heterosis (21.2%) was computed for seed yield. The lowest heterosis (–19.3%) and heter obeltiosis (-22.4%) were observed for hull rate. The lowest standard heterosis (-22.0%) was measured for oil yield. Regarding the studied traits, most favorable performances were shown by the 11th cross (2453-A × 2644-R). Among inbred lines, the female 2453-A and the male 2644-R exhibited higher hybrid vigor than the others.

The frequency and spectrum of morphological mutations, raised in M2 after sunflower mature and immature seed treatment with ethylmethanesul phonate (EMS), were studied. Mature seeds of 3 self-pollinated lines (ZL9, ZL102, ZL169) and immature seeds of 2 lines (ZL102 and ZL169) were treated with EMS at the concentrations of 0.01%, 0.1% and 0.5% for 6 and 12 h and 0.01% and 0.1% for 6 and 12 h, respectively. We isolated and described 18 types of mutation, which were classified into the following groups: chlorophyll deficiency (6), leaf (5), stem and (4) ray floret shape and color (3). Genotypic differences were revealed for the spectrum of mutations occurring after mutagenic treatment of mature and immature seeds. Differences in mutation spectrum existed in the studied lines after treatment of mature seeds. Mutation frequency after immature seed treatment did not exceed the amount of mutations after mature seed treatment where the maximum frequency amounted to 13.2%. Chlorophyll deficiency mutations averaged a half and more of the visi ble morphological mutations.

A field experiment was conducted at Agricultural Research Station, Bha vanisagar, Tamil Nadu Agricultural University, Coimbatore, India during rabi (Sep-Oct) seasons of 2000 and 2001 to study the pollen use efficiency of sunflower lines cms 234 A and RHA 6D-1. The experiments consisted of four treatments, 100% pollen (T0), 75% pollen plus 25% borax as filler material (T1), 50% pollen plus 50% borax as filler material (T2) and 50% pollen and 50% flour of finger millet (Eleusine coracana L.) (T3). The results showed that the treatments were significantly differed from each other. All the traits studied recorded superior performance only at 100% pollen availability; the seed yield was very much increased only with an assured availability of sufficient pollen for fertilization. The mean comparison of the treatments for all the characters was T0>T1>T2>T3. Though the seed yield was reduced to some extent while supplementing pollen with filler material, it was concluded that 75% pollen with 25% borax filler material may be used instead of 100% pollen, without affecting the economic yield much in the case of pollen scarcity /pollen insufficiency/ in locations where “pollen theft” is common. Borax can be used as supplement at the time of pollination. The use of flour of finger millet as the filler material in the case of pollen insufficiency during pollination does not have any effect on the seed yield and yield attributing characters. In that case the yield was affected only below 50% of pollen availability.

The inheritance of stem, petiole and bract tip color was studied in the cross cms-103A × PFNB-2. F1 studies revealed that purple color of stem, petiole and bract tip is dominant over green color of these plant parts. Complementary gene action was observed for these characters in F2. The genes governing the inheritance of stem, petiole and bract tip colors were designated as Ptla and Psmb, Ptla and Ptlb, Ptla and Pbtb, respectively, the gene Ptla being common to all three traits.

Sunflowers are annually grown in Serbia at 150,000 to 200,000 ha, with average yields of about 2.0 t/ha. Yield variations are due to uneven and unfavorably distributed rainfall. Under irrigation, yields reach 3 t/ha in commercial production and 4 to 5 t/ha in experiments. In 2000-2004, two sunflower hybrids developed at Novi Sad Institute were tested in irrigation trials on a chernozemic soil. In 2000, which was dry, the average yields with and without irrigation were 5.04 t/ha and 3.97 t/ha, respectively. In 2001, which was rainy, yields with and without irrigation were similar, around 3 t/ha. In 2002, which was moderately dry, the average yields with and without irrigation were similar, around 4.5 t/ha, due to development of diseases in irrigation. In 2003, which was exceptionally warm and dry, sunflower yields were reduced because of a short growing season. The average irrigation effect for the two tested hybrids was 27%, and as much as 51% for the hybrid Dukat. In 2004, which was very favorable for production, sunflower yields were uniform and quality was high. Irrigation practice positively affected oil yield of both hybrids, especially in the dry years. These results justify the application of irrigation practice in sunflower production. The hybrid NS-H-111 exhibited high adaptability and yield stability when grown under variable weather conditions. The hybrid Dukat showed to be suit able for late planting and double cropping when grown in irrigation.

The general and specific combining abilities among 20 cytoplasmic male sterile inbred lines and four testers were estimated in order to study the poten tial of these materials in a sunflower (Helianthus annuus L.) breeding program. Test cross progenies were evaluated in three environments. Plant height, days to 50% flowering, 1000-kernel weight, seed oil content and grain yield were evaluated. Seed oil content, plant height and 1000-kernel weight presented the largest proportional contribution of cms inbred lines and testers, indicating the predominant role of the additive component for these traits. On the other hand, line × tester interaction exhibited the greatest contribution to grain yield suggesting the presence of non-additive genetic effects. The testers showed capacity to discriminate within the set of inbred lines.

On-farm trials were conducted during 2001 and 2002 rainy seasons to evaluate the effects of nutrients and moisture conservation practices on the growth, yield and economics of sunflower (Helianthus annuus L.) cultivars grown on vertisols of Raichur district, Karnataka, India, under rainfed condi tions. Two-year results revealed that the recommended method of moisture conservation along with the recommended fertilizer practice gave significantly higher seed yield (994 kg/ha), net returns (Rs.10503/ha) and cost-benefit ratio (2.62) than the conventional method of moisture conservation and fertilizer practices. Also, the former method surpassed the latter in plant height, head size, stem thickness and 1000-seed weight. The hybrid KBSH-44 showed significantly favorable responses with respect to growth and yield components. It gave higher yield (993 kg/ha), net returns (Rs.10222/ha) and cost-benefit ratio (2.84) than the hybrids KBSH-1 and MSFH-17 when grown on vertisols under rainfed conditions.

Wide adaptability of sunflower and wide range of climatic conditions existing in Pakistan make it possible to have two crops of sunflower in a year, i.e., in spring and fall. Field experiments, one in spring and another in fall were conducted at the University of Arid Agriculture, Rawalpindi, Pakistan, to evaluate the influence of seasonal variations on yield and yield components of sunflower. Five sunflower hybrids were planted in a randomized complete block design in three replications. Two inner rows were harvested for measurements of yield and yield components. It was observed that head size of spring crop was larger than fall crop. Contrary to head size, 1000-seed weight of the fall crop was larger than that of the spring crop. However, final yield of the spring crop was greater than that of the fall crop. It led to the conclusion that having spring crop is the best option, while fall crop could be supplementary one, to increase the production of oilseeds.

The sunflower downy mildew in India was reported around 1986 in Marathwada region of Maharashtra States where sunflower is extensively grown. A survey in this region conducted in 1995-96 revealed 36.67% disease incidence on farmers' fields. Of the 1944 sunflower genotypes screened against downy mildew in infected plot, eight hybrids and one population that showed resist ance to downy mildew and high yield potential were released for commercial cultivation in India. Release of such resistant hybrids has helped to minimize the disease incidence on farmers' fields. The disease incidence has been mini mized considerably in farmers' fields.

Sunflower (Helianthus annuus L.) is susceptible to diseases of various kinds. Downy mildew is a destructive disease in many sunflower-growing countries. The disease is mainly seed-transmitted in nature. Hence, in the period 2000-2003, a new emulsion form of metalaxyl fungicide, Apron XL-35 E.S., was evaluated for its efficacy as seed dressing in the management of sunflower downy mildew disease at Oilseeds Research Station, Latur (M.S.). The three years of experimentation revealed that Apron XL-35 E.S. when used for seed dressing at 3 ml/kg of seed could effectively manage downy mildew, without phytotoxic effects.

The edible oil imports bill rising from Rs. 77 million in 1969-70 to Rs. 3,900 million in 2002-03 has overburdened the economy of the country. Only 30% of the total needs are met through local production, while 70% are provided by import. Major share of the domestic production of edible oil comes from cottonseed and canola, 67 and 19.6%, respectively. The remaining 13.4% are contributed mainly by sunflower. Although it is a high oil, high yielding crop that gives high returns to the farmers, no serious effort has been made to increase the local production of sunflower. Consequently, the sunflower acreage declined from 144,191 ha in 1998-99 to 107,717 ha in 2002-03 and the production from 194,544 to 128,531 t during the same period. The 1998-99 acreage was the maximum area under sunflower achieved. The big fluctuations in sunflower acreage and production are due to its price on the market. In the period of last 15 years, the sunflower acreage in Pakistan expended from 29,500 to 107,700 ha. The sunflower production rose at the annual rate of 9.9%, comprised of a 9.7% expansion in acreage and a minor improvement in productivity amounting to 0.16%. This increase was not sufficient to meet the requirements of the country. There is a big gap between the potential and actual yields of sunflowers. More than 70% of the potential have not been achieved yet. For this purpose the R2 value was also calculated and, keeping in view the fluctuations in the time series data, second-degree equation was also measured. Logarithmic and exponential functions were also tested but the var iability in the data measured by the R2 value was best represented by second degree polynomial function. When the data seem to depart more or less widely from linearity in regression or time series analysis we must consider fitting some other curve instead of the straight line. The R2 value was also improved with second-degree polynomial function for production from 43% to 58% showing a better fit of the trend line. The sum of the error terms was “0” for second-degree polynomial function but it gave a better fit due to a higher R2 value. The higher b value for production portrays an increase in the productivity. The sum of squares for the estimated and observed values was 0. However, due to a low value of the coefficient of determination with linear trend and variation in the data, second-degree polynomial function (parabola) was estimated which gave a higher value of the coefficient of determination. With the use of second-degree polynomial function the value of coefficient of determination increased from 50% to 60%.