Volume 40, Issue 66 -

Somatic embryogenesis in vitro provides an efficient means of plant multiplication, facilitating sunflower improvement and germplasm innovation. In the present study, using interspecific amphiploids (2n=4x=68) between cultivated sunflower and wild perennial Helianthus species as explant donors, somatic embryos were induced directly from the surface of corolla tubes at the late uninucleate or binucleate microspore development stage. Primary somatic embryos (PSEs) were obtained in amphiploids G08/2280 ( H. pumilus ×P21) and G08/2260 (NMSHA89× H. maximiliani ). The PSE induction frequency of G08/2280 on synthesized Medium A and B was 30.27 % and 42.42 %, respectively, while that of G08/2260 was 5.89 % and 12.16 %, respectively. The difference of PSE induction frequency was significant between G08/2280 and G08/2260 ( P =0.0058), but was non-significant between induction Medium A and B ( P =0.1997). Secondary somatic embryos (SSEs) were rapidly produced from PSEs on subculture Medium 1 with the induction frequency of 100 %. The mean number of SSEs produced from each PSE was 19.2 and 12.2 in G08/2280 and G08/2260 within 30 d of subculture, respectively. Mature SSEs were gradually converted into young shoots on hormone-free subculture Medium 2, with the mean number of small green shoots produced from each PSE of 22.0 and 18.7 in G08/2280 and G08/2260, respectively. Through the additional process of rooting for some shoots without roots on half-strength of MS medium adding 0.25–0.5 mg/l NAA, 0.5 mg–1.0/l IBA, SE-derived shoots without roots gained about 40 % rooting frequency. Regenerated plants acclimated successfully and displayed similar morphological and chromosome number to the amphiploid donors.

After mutagenic treatment of sunflower seeds two traits of altered leaf shape were found – obtuse shape of leaf tip and strongly sinuate (fringed) leaf margin. To study the inheritance pattern of these traits, the mutant lines were crossed with the source lines and between themselves. It was shown that the traits of obtuse leaf and fringed leaf are recessive and inherited as monogenic traits when mating with the source line. In crossings of mutants, all F 1 plants had normal (acute leaf tip, fringe absence) phenotype. In F 2 generation, the 1/16 of plants with obtuse leaves and 1/4 of fringed plants were found. It was concluded that the shape of leaf tip is under the control of two genetic loci with duplicate genes interaction without cumulative effect. In that case obtuse shape of leaf tip is a double recessive homozygote. Fringed leaf is recessive in relation to the normal serrate leaf (absence of fringe) and inherited according to a single gene model. The chi-square test for goodness-of-fit indicated that the observed segregation pattern for the traits of leaf tip shape and leaf margin shape fit well to the expected ratio assuming that those two traits of leaf are inherited independently.

This study aimed to evaluate the morphology of sunflower productivity and oil content of seeds and sunflower cake, cv. Helium 250, subjected to doses of organic manure on dryland. The design was a randomized block with six treatments and four blocks and nine observations. Treatments consisted of manure levels: T1 - without adding manure, T2 – 7.5 t ha –1 , T3 – 15 t ha –1 , T4 – 22.5 t ha –1 , T5 – 30 t ha –1 , T6 – 37.5 t ha –1 . For morphological evaluation noted the diameter of the chapter, plant height and number of leaves. We estimated the yield of achenes from the weight of 100 seeds, and productivity of oil and cake from seed production. The oil content of the seed was determined by nuclear magnetic resonance at the Laboratory of Technology (LATEC) Embrapa Cotton, while the pie by ether extraction determined in the Laboratory of Animal Nutrition of the Center for Agricultural Sciences, Federal University of Paraíba. The plant height and head diameter of sunflower were positively influenced (P<0.05) by the dosage of manure compared to treatment without manure. The cattle manure fertilization promotes increased sunflower productivity, reflecting directly on grain production, as well as in the production of oil and pie. It was possible to obtain average 127.37 kg ha –1   Mass crude oil sunflower cultivar Helium 250. The maximization of grain and pie production can be achieved with organic manure of bovine in 37.5 t ha –1 , what means a fertilization with 352.5 kg N ha –1 .

The genetic diversity study of 39 broomrape populations from the Republic of Moldova was performed using 12 highly polymorphic SSR primer pairs, which shown the high level of polymorphism (average PIC value 0.57). We found that some of the SSR primers (Ocum-59 and Ocum-108) produced polymorphic bands suitable for discrimination between the studied populations. The diversity analysis within broomrape populations revealed a higher number of detected alleles and heterozygous loci in the accessions from the Southern region when compared to the Northern and Central ones. The average PIC values for the Northern, Central and Southern accessions ranged from 0.43, 0.48 to 0.56, respectively. Some populations from the Southern region (especially, Carabetovca, Alexanderfeld, Stefan-Voda and Slobozia Mare) have shown the major differences in the profiles obtained and presented the high level of genetic variability. The dendrogram based on genetic distance divided the 39 broomrape accessions into twelve clusters. High variability of O. cumana populations at molecular level was observed, which could be useful for further genetic studies and resistance-breeding programs.

The general (GCA) and specific (SCA) combining abilities among eight cytoplasmic male sterile lines and six restorers as testers were estimated using line ×tester method to assess the potential of the materials in the sunflower ( Helianthus annuus L.) breeding program. Test cross progenies along with their parents were evaluated in two sowing dates. Both lines and testers had significant differences for all the traits except seeds per head. The lines: LA2 and LA7 were superior combiners with significant positive general combining ability (GCA) effects for seed yield and most of the yield components. Among the testers: RF1 and RF6 were good combiners for seed yield. Most of the lines and testers with significant positive GCA effects for seed yield had significant positive GCA effect for oil yield. LA7×RF6 had significant positive specific combining ability (SCA) effects for seed width, seed yield and oil yield. The crosses LA4×RF1 and LA7×RF6 had significant SCA effects for seed yield and oil yield. Estimating degree of dominance more than one for all the traits except seeds per head and percentage of kernel indicate the importance of non additive genetic effects for them; therefore for improving these traits, hybrid breeding will be more effective.

Nine CMS analogues from different cytoplasmic sources and their common maintainer were crossed with four perfect restorers from PET-1 source to develop of 40 sunflower hybrids. The experiment was conducted during spring season 2011 and 2012 two years continuously, under two different water environments, normal irrigated and water stress environment, where irrigation was stopped after the anthesis. The analysis of variance revealed significant differences among the sources for day to flowering, days to maturity and seed yield under both the environments, both the years and pooled over the years. The variance due to GCA and SCA showed that gene action was additive for maturity whereas, non-additive genetic effect was observed for days to flowering and seed yield under both the environments. The CMS analogues E002-91A ( H. annuus ), PKU-2A ( H. annuus ), and ARG-3A ( H. argophyllus ) were recorded as good combiner for early flowering in both the environments. The CMS analogs E002-91A and ARG-3A were observed good combiners for early flowering, early maturity and high seed yield, whereas, NC-41B from conventional CMS source H. petiolaris (PET-1) was recorded good combiner for late flower and early maturity and poor combiner for seed yield under both the environments. Among testers P69R was recorded good combiner for late flowering under normal water environment while, in water stress it was good combiner for early flowering but it was not good for seed yield. RCR-8297 was recorded for good combiner for late maturity and high seed yield under both the environments. The SCA estimates were highest in cross E002-91A×RCR-8297 and PKU-2A×P124R and ARG-6A×RCR-8297 for early flowering and early maturity under both the environments. These new cytoplasmic male sterility sources can be substitute of the classical (PET-1) source with added advantage for early maturing and high yielding.

A half diallel cross between five divergent sunflower genotypes was evaluated under two contrast locations of Kafr El-Hamam (fovourable soil as a control) and Tag Al-Ezz (as salt affected soil) Agricultural Research Stations using randomized complete block design with three replications. High significance variation among genotypes and their components was detected for all studied traits at both and combined locations. Selection in early generations would be effective at both locations for improving days to 50 % flowering, days to physiological maturity, plant height, head diameter, No. of green leaves plant –1 and seed oil content, but the remaining studied traits took an opposite trend. The parent L 125 behaved as the best combiner at both locations for seed weight plant –1 and one or more of its components. The cross L 460 ×L 335 was found to be superior and exhibited highest specific combining ability effects and heterosis at both locations for seed weight plant –1 and one or more of its attributes. Gardner and Eberhart and Jones’s analyses (modified Hayman analysis) gives the same information as Griffing’s analysis method 2. Moreover, Hayman’s analysis may be given more information over the others about genetic component, so recommended using any one of these three methods along with Hayman’s analysis.