Productivity performance of bread winter wheat genotypes of local and foreign origin

G. Raykov1*, P. Chamurliyski1, S. Doneva1, E. Penchev1, N. Tsenov2

1Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria 2Agronom I Holding, 9300 Dobrich, Bulgaria

(Manuscript received 12 October 2015; accepted for publication 18 October 2016)

Abstract. The proper choice of parental forms is the basis for developing superior varieties with valuable agronomic properties. A priority in modern breeding is increased productivity. The aim of this study was to establish the relative contribution of the yield traits to the productivity of common wheat accessions of different geographical origin. The trial was conducted during 2012 – 2014 at Dobrudzha Agricultural Institute, General Toshevo. The study included 118 varieties and lines originating from Europe, Asia and North America. The tested materials were grown in a randomized block design in three replications, the plot size being 7.5 m2. Six cultivars were used as standards: Aglika, Pobeda, Enola, Sadovo 1, Antonovka and Pryaspa. Number of grains per spike, number of grains per m2 and thousand kernel weight had the highest positive influence on grain yield. The highest levels of productivity were reported in cultivars PKB Vizelika, PKB Rodika, Joana and Midas averaged for the two years of the study, cultivar Vizelika with origin from PKB – Serbia realizing a yield of 9.03 t.ha-1. Despite environmental effect and interaction, significant genotypic modality on the investigated traits was observed and analyzed. All studied accessions can be successfully included in a breeding program to increase productivity.

Sensitivity of promising cherry hybrids and new cultivars to economically important fungal diseases

K. Vasileva1, S. Malchev2*, A. Zhivondov2

1Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria 2Fruit Growing Institute, 12 Ostromila, Plovdiv, Biulgaria

(Manuscript received 2 June 2016; accepted for publication 29 August 2016)

Abstract. As a result of years of developing the breeding programme for creating novel sweet cherry cultivars in the Fruit Growing Institute (FGI), Plovdiv, a reach hybrid fund from first and second hybrid generation is created. Of the selected and propagated hybrids at a more advanced stage of testing are 11 hybrids along with three new cultivars of the FGI Plovdiv (‘Kossara’, ‘Rosalina’ and ‘Trakiiska hrushtyalka’) grafted on three rootstocks were tested for sensitivity to causers of economically important fungal diseases in sweet cherry – cherry leaf spot (Blumeriella jaapii (Rehm) Arx), shothole blight (Stigmina carpophila (Lev.) Ellis) and brown rot (Monilinia fructigena (G. Wint) Honey). The degree of infestation under field conditions is reported by determining the index of attack on leaves and fruit, using the formula of McKinney. As the most sensitive elites are outlined elite El.17-31 (to cherry leaf spot) and elite El.17-136 (to shothole blight). The cultivars ‘Kossara’ and ‘Trakiiska hrushtyalka’ exhibit an average resistance to the three diseases, as the values for the index of infestation are lower or similar to those of standard cultivars ‘Van’ and ‘Bing’, while ‘Rosalina’ demonstrated sensitivity to shothole blight and brown rot. Interesting is the elite El.17- 37 demonstrating the least infestation of Blumeriella jaapii – 7.33% and Monilinia fructigena – 6.67%. The same has a set of valuable qualities as late maturing date and very large fruits with excellent sensory profile, making it a potential candidate cultivar.


Evaluation of small size fruit peppers Capsicum annuum spp. microcarpum with cluster and factor analysis

V. Kuneva1*, M. Nikolova

1Department of Mathematics, Informatics and Physics, Faculty of Economics, Аgricultural University, 4000 Plovdiv, Bulgaria 2Institute of Plant Genetic Resources K. Malkov, 4122 Sadovo, Bulgaria

(Manuscript received 4 July 2016; accepted for publication 28 August 2016)

Abstract. 43 specimens of local small size fruit peppers (Capsicum annuum sub. microcarpum) were examined and characterized with reference to the indicators: shrub height, number of shrub branches, leaf length, leaf width, fruit length, fruit diameter, one pepper mass, 1000 seeds mass, number of fruit on one plant. The research was conducted in the experimental field of Institute of Plant Genetic Resources (IPGR), Sadovo, in the period of 2009 – 2011. On the base of the examined indicators, the specimens were evaluated complexly through a hierarchical cluster analysis. Genetically close specimens were grouped in 7 main clusters and presented with the help of a dendrogramm. In addition, a factor analysis was made to establish the indices with the highest influence of distribution of the specimens in the received clusters. The main 10 indicators from the research are reduced to 4 factors, which are responsible for 76.16% from the total dispersion of variables. The principal indicators that separate the examined specimens in clusters are: leaf length and width, fruit length and diameter, as well as mass of one pepper. This classification helps for a higher objectiveness of evaluation. It leads to a more complete characterization of small size fruit peppers for their more rational use in different selective programs.


Evaluation of the combining ability of mutant maize lines

V. Valkova*, N. Petrovska

Maize Research Institute, 5835 Knezha, Bulgaria
(Manuscript received 6 June 2016; accepted for publication 18 August 2016)

Abstract. The study shows the results of a preliminary evaluation of the combining ability for grain yield of 17 mutant maize lines. For the purpose the top cross method for early testing and the mathematical model of Savchenko for analysis of the general and the specific combining ability were used. The lines were tested on three testers with high general combining ability that belong to two genetic groups: K 46 52 and XM 552 from SSS and N 192 – Lancaster. For the purposes of evaluation of the productive abilities of the received top cross two preliminary varietal experiments were carried out at the experimental field of Maize Research Institute, Knezha As a result of the conducted experimental work and the analysis it was found that the highest general combining ability have lines XM 11 6 and XM 12 1. These lines can be included as components of high-yielding synthetics or as testers in analyzing crosses to determine general combining ability in early stages of the selection process. The above lines with high specific combining ability – XM 11 13 and XM 11 46 are suitable for inclusion in combinations to develop high-yielding hybrids. Three of the tested lines XM 11 7 11 XM 10 and XM 11 11 have both high GCA and SCA. These lines can be used in corresponding breeding in the selection programs.


Characterization of the Bulgarian sunflower hybrid Valin

G. Georgiev*

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria (Manuscript received 1 July 2016; accepted for publication 26 August 2016)

Abstract. A male sterile two-linear sunflower hybrid was developed at Dobrudzha Agricultural Institute – General Toshevo using the method of inter-linear hybridization. The mother component is line 10517 which possesses cytoplasmic male sterility, and the father component is line 10595R, a fertility restorer of branched type. Both parental forms have very good general and specific combining ability. Hybrid Valin is medium early, with vegetation period of 110 – 115 days, plant height 165 – 175 cm and head diameter 17 – 18 cm. The percent of kernel in seed is within the range of 65 – 73%. Seeds have absolute weight 50 – 55 g, and oil content in seed is 46 – 50%. The hybrid is resistant to lodging and moderately resistant to phoma and phomopsis. The resistance to downy mildew is as high as 95 % up to race 700, and the resistance to the parasite Orobanche is 100% (races A-F). In the breeding fields of DAI the hybrid went through three- year testing according to a scheme and growing technology approved for this crop. During the first two years of the control testing it exceeded the mean standard by seed yield with 11.0% and 14.4%, respectively. During the third year, hybrid Valin was above the mean standard with 10.9% by seed yield and with 6.6% by oil yield in a unified competitive varietal testing. The maximum yield obtained at DAI was 4483 kg/ha, and the maximum oil content was 50.1%. In 2007 and 2008 hybrid Valin went through official testing within the structure of the Executive Agency of Variety Testing, Field Inspection and Seed Control of Bulgaria. By the index seed yield, the exceeding of the mean standard was 23.6 % in the first year, and in the second the yield was with 1.4 % below the standard. Oil content was a little below the standard in both years. The aim of this investigation was to make as full as possible a characterization of the new registered sunflower hybrid Valin on the base of biological,phytopatological and economical indices.


Economical qualities of crosses between doubled haploid sugar beet lines

G. Kikindonov, Tz. Kikindonov, S. Enchev*

Agricultural Institute, 9700 Shumen, Bulgaria
(Manuscript received 14 May 2016; accepted for publication 23 June 2016)

Abstract. The gynogenesis of isolated in vitro ovules is a basic method for the receipt of haploid plants and doubled haploid forms of sugar beet. The
application of the induced haploidy is an excellent possibility for enrichment of the sugar beet gene fund and allows accelerated creation of highly homozygous
and genetically stable lines. Ten years field tests were conducted on the experimental fields of Agricultural Institute – Shumen to study the practical value of dihaploid monogerm and multigerm lines for the hybrid breeding of sugar beet. All the tested dihaploid lines formed higher root yields than their initial lines, maintained by classical methods. The monogerm dihaploid 150-4 and the multigerm tetrahaploid 48 combined that with proven higher sugar content. The
diploid hybrids of the monogerm dihaploid 150-4 and the multigerm dihaploid 58 lines realized the highest white sugar yields, significantly higher than the yield of the Standard varieties. The triploid hybrids of the monogerm dihaploid lines 54-4 and 150-4 and of the multigerm tetrahaploid 55 pollinator gave the highest white sugar yields, and could be presented to the State Agency for tests and certification as new Bulgarian sugar beet varieties.


Genotype-environment interaction and stability analysis for grain yield of winter barley in the conditions of North-East and South Bulgaria

M. Dimitrova-Doneva1*, D. Valcheva1, G. Mihova2, B. Dyulgerova1

1Institute of Agriculture, 8400 Karnobat, Bulgaria
2Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

(Manuscript received 30 October 2015; accepted for publication 8 February 2016)

Abstract. The aim of this study was to evaluate the grain yield of winter varieties of feed barley in different environments and to determine their stabilities. Grain yield performances were evaluated for three years (2008/2009, 2009/2010, 2010/2011) at three locations (Karnobat, General Toshevo and Sredets) in Bulgaria. The combined analysis of variance indicated that environmental factors were the most important sources affecting yield variation and these factors significantly explained 90.58% (4.40, 59.20 and 26.98% for year, location and their interactions) of the total sum of squares due to G + E + GE interaction. The average grain yield of the studied varieties of winter feed barley ranged from 5.16 t/ha (Veslets) to 5.46 t/ha (Radul). The genotypic responses to environmental changes were assessed using a linear regression coefficient (bi), the variance of the regression deviations (SDi), Lin and Binns cultivar superiority index (Pi) and GGE biplot analysis. The variety Radul was the best at combining yield stability and high mean grain yield based on most stability statistics. Variety Veslets was the most stable, but lower yielding than other studied varieties.


Genotype by environment interaction in mutant lines of winter barley for grain yield

B. Dyulgerova*, N. Dyulgerov

Institute of Agriculture, 8400 Karnobat, Bulgaria
(Manuscript received 30 October 2015; accepted for publication 8 February 2016)

Abstract. The study was conducted to analyze grain yield performances of twenty eight mutant barley lines, two new feed barley varieties and two check varieties, between 2011 – 2014 growing seasons. The experimental layout was randomized complete block design with four replications. Additive main effects and multiplicative interactions analysis (AMMI) revealed that the yield performances of genotypes were under the main environmental effects of genotype by interactions. The first two interaction principal component axes (IPCA 1 and IPCA 2) were significant and cumulatively contributed to 89.84% of the total genotype by environmental interaction. Вoth the GGE and AMMI1 biplots identified G9 as the highest yielding mutant line among the studied genotypes showing relative stability and can be recommended for further evaluation for variety release. In addition, G30 and G26 had high stability with high grain yield and they were identified to be a valuable source for yield improvement in winter barley breeding programs.


Hybridization between cultivated sunflower and wild annual species Helianthus petiolaris Nutt.

D. Valkova*, G. Georgiev, N. Nenova, V. Encheva, J. Encheva

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

Abstract. InterspecifichybridizationwascarriedoutbetweensterileanaloguesofcultivatedsunflowerlineswithnormalcytoplasmandwildannualHelianthus petiolaris accessions from a collection of DAI-General Toshevo. The obtained F1 progenies were characterized from morphological, phenological, biochemical and phytopathological point of view. Hybrid forms with resistance to leaves pathogens, downy mildew and broomrape were obtained. They were distinguished with diversity of seed oil content. The most variable phenological phases of hybrid plants from all crosses were duration of flowering period and germination. The hybrid plants from crosses 325 A x E-142 and 813 A x E-142 were characterized with higher seed oil content than the other studied crosses. All hybrid plants, originating from wild Helianthus petiolaris accession E-142 were resistant (100%) to downy mildew and to the parasite broomrape. They were also with immune type of reaction to the leaves pathogens and with the highest oil content in seeds. Among the included in the investigation accessions, E-142 was characterized with the highest crossability. The hybrid plants of the crosses included in this study were carriers of Rf genes and could be used for developing restorer lines.


Investigation on the parthenogenetic response of sunflower lines and hybrids

M. Drumeva*, P. Yankov

Department of Plant Production, Faculty of Marine Sciences and Ecology, Technical University Varna, 1 Studentska, 9010 Varna, Bulgaria

Abstract. When applying gamma-ionizing radiation for induction of parthenogenetic doubled haploidy, the female genotype exercises certain effect. The effect of the female may be expressed in lack of parthenogenetic response, in lower responsiveness or in specific selectiveness with regard to the type of parthenogenetic development. This investigation studied the parthenogenetic response of two lines and three hybrids of sunflower used as initial female material. Parthenogenetic reaction were registered in the tested hybrids, while parthenogenetic embryos were not obtained from some variants including lines, and, on the whole, lower responsiveness was determined. The effect of the female genotype was expressed in differences both in the responsiveness of the investigated lines and hybrids to induction of parthenogenetic development and in the variable reaction among the different lines and hybrids. The variations in the parthenogenetic response of the individual hybrids subjected to this investigation, which differed between themselves by their nuclear-cytoplasmic characteristics, were indicative for the dependence of the method on the genotypic and cytoplasmic specificity of the initial female material.