Volume 43, Issue 73

The purpose of the study is to identify the use of qualitative and quantitative morphological traits to ascertain genetic affinity and identification of sunflower lines. A collection of 39 sunflower lines was studied according to morphological qualitative traits described in the method of establishing differences, homogeneity, stability and quantitative traits (plant organ size, 1000 seeds weight, oil content). Several lines of unknown origin were identified to each other. The material of the collection of lines proved the possibility of clustering by the method of link analysis on a set of morphological features. Generalized data show that only three lines out of 39 do not correspond to known lineages in their clusters, which is 92% of the correct cluster definition. The results of clustering, identification and breeding records were compared. To be consistent with the breeding records classification, the number of distinguished traits that are not similar must exceed 20 names given to the score.

The number, shape, size and color of the sunflower ray flowers are widely used as marker traits in hybrid seed production, for identification of genotypes, in ornamental floriculture. However, there is not enough information about the genetic control of these traits. The inheritance of the number of ray flowers and their absence on inflorescences was studied in cultivated sunflower. In the first case, two inbred lines of mutant origin with a contrasting manifestation of the studied trait were crossed. The F 1 hybrid held an intermediate position between the parents, but approached the parental line with a large number of ray flowers. The average value of the number of petals in F 2 was close to F 1 . The study of segregation in F 2 showed that the trait “number of ray flowers” is inherited polygenically and controlled by three pairs of non-allelic genes with additive effects. The inheritance of the absence of ray flowers was studied by crossing a line with petals and an apetalous accession. F 1 hybrid showed ray flowers, and in F 2 , segregation close to 42 (with ray flowers): 22 (without ray flowers) was observed. This implies participation of three non-allelic genes in the control of this trait, one of which in a recessive state suppresses the action of two other recessive genes. The revealed patterns of inheritance expand the information in the field of private genetics of sunflower and allow performing more purposeful breeding of this crop.

The investigation was carried out during 2014–2016 in the land of General Toshevo, the South Dobrudzha region of Bulgaria on slightly leached chernozem soil type. The effect of the types of soil tillage for sunflower given bellow was followed: ploughing at 24–26 cm, chisel-plough at 24–26 cm, disking with disk harrow at 10–20 cm and direct sowing (no-tillage) on the bulk density, the moisture content and the temperature of soil. The additional soil tilths of the areas subjected to ploughing, chisel-ploughing and disking with disc harrow included double spring pre-sowing cultivation with harrowing. To destroy the emerging weeds in the variant with direct sowing, a total herbicide was applied. The investigated physical parameters of soil were followed during three main stages of sunflower development: emergence, flowering and technical maturity. The bulk density of soil was determined by soil samples taken from the 0–10, 10–20 and 20–30 cm layers. The soil temperature was read at 800, 1200 and 1600 h to depth 2, 5, 10, 15, 20 and 25 cm with classical soil thermometer. For evaluation of the results dispersion and regression analyses were used. In the slightly leached chernozem soil type, the conventional ploughing leads to lower bulk density in the cultivated soil profile. Under minimal tillage, slight increase of bulk density of the layer underlying the cultivated one was observed over time. The bulk density under tillage without turning of the soil layer and no-tillage was changed and formed primarily under the influence of physical and climatic factors, and under minimal tillage – under the cultivated layer. Under all investigated types of soil tillage, bulk density increased down the soil profile. Replacing ploughing with tillage without turning of the soil layer, minimal and no-tillage lead to decrease of soil temperature. The most significant differences were observed in the 0–10 layer, which, on its part, conditioned accumulation and transfer of thermal energy along the soil profile. The soil temperature decreased with the reduction of the number and depth of the soil tillage operations. The temperature amplitudes between the surface layer and the underlying soil horizons in the areas with ploughing, chisel ploughing minimal and no-tillage were lower. The results concerning the values of the investigated physical properties of soil under different types of soil tillage were statistically significant at different levels of P.

Sunflower breeding aims to developing good heterotic hybrids which can be achieved by tapping combining ability of hybrids belongs to diverse parents. Nine diversified CMS lines along with one maintainer lines were hybridized with four male lines in a line × tester manner thereby, developing a total 40 hybrids. The experimental material was grown over two environments i.e. recommended irrigation and other moisture stress environments continuously for two years 2011 and 2012 in randomized complete block design with three replications at Punjab Agricultural University, Ludhiana, Punjab, India. The experiment was design to estimate combining ability of parental lines, gene effects and effect of divers CMS sources on oil content and quality traits. It was observed that the non-additive component of genetic variance played major role in inheritance of these traits as recommended by analysis of variance of combining abilities and analysis of genetic variance components. Further supporting this conclusion was the fact that the GCA/SCA ratio for oil content and quality traits observed in F 1 generation was less than one under both the environments. These results indicated the preponderance of dominant gene action and the feasibility of hybrid sunflower development. GCA estimates revealed that CMS analogues CMS-XA (Unknown), ARG-2A ( H. argophyllus ) and PRUN-29A ( H. praecox spp. runyonic ) were very good combiner for oil content under both the environments. The pollen parents RCR-8297 and P69R were observed as very good combiners for oil content and stearic acid under moisture stress condition. The male parent P100R was recorded very good combiner for oil content under normal environment while, RCR-8297 and P100R were very good combiners for oleic acid under both the environments. A total seven crosses were identified for oil content and eight crosses for oleic acid as having high SCA effects under both the water regimes.

Sunflower is cultivated around the globe to meet various nutritional, medicinal and industrial needs. The seed is a rich source of edible oil, protein, vitamins, antioxidants and other micronutrients. It is considered a source of healthy diets and has been recommended to improve the human immune system as well as to cure various chronic diseases. Sunflower seed oil contained polyunsaturated fatty acids (linoleic acid), tocopherols and phytosterols, which tends to lower low-density lipid and improve immunity against various human diseases. Its seed and plants parts have been directly exploited as a source of herbal medicine. Methanolic extract of seed and other parts contained diterpene, carboxylic acid, aldehyde, steroid, polyphenol, vanillic acid, ferulic acid, trans-caffeic acid, coumaric acid, nicotinic acid, allelochemical and other aromatic compounds, which may help to cure several chronic human diseases without side effects as mentioned in this review. Future research should be carried out to fully exploit the usefulness of this plant against epidemic outbreaks.

New traits that are useful for the cultivated sunflower can be received by applying classical breeding methods. A new form sunflower that is resistant to herbicides Pulsar and Express was obtained by hybridization between the sunflower mutant M-95-674 and the line HA 425. Test results from the period 2017–2019 confirm the resistance to both herbicides. This resistance can be transferred into other classical selected lines.