Knezha 560 – a new mid-late maize hybrid

  1. V. Valkova, N. Petrovska


Maize Research Institute, 5835 Knezha, Bulgaria


DOI: 10.15547/ast.2018.03.036

(Manuscript received 14 May 2018; accepted for publication 29 June 2018)


Abstract. Тhe article presents a short characteristic of morphological, biological and economic qualities of a new maize hybrid Knezha (Kn) 560. The hybrid is a single cross, from mid-late group – FAO 500-599. It is recognized in 2017 by the Expert Commission of Executive Agency of Variety Testing, Field Inspection and Seed Control (EAVTFISC). At the points of ecological variety trails (EVT) and EAVTFISC it was compared with the American hybrid PR 35 P 12 and the Bulgarian hybrid – Knezha 509. During the testing period in the experimental field of the Maize Research Institute (MRI) – town of Knezha, the three-year average grain yield of hybrid Knezha 560 exceeded the standard PR 35 Р 12 hybrid by 19.3% and Knezha 509 hybrid by 37.3%. In the EAVTFISC system, the new hybrid exceeds the middle standard by 0.8%. The hybrid is stress-tolerant and resistant to economically important diseases and pests of maize. With this high-yielding and competitive maize hybrid, the group of mid-late maize hybrids offered on the Bulgarian seed market is being filled.

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.


Effect of cocoon fluorescence, silkworm hybrid and gender on sericin content of Bombyx mori L. silk thread

M. Panayotov*

Department of Animal Science – Non-ruminants and other animals, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
(Manuscript received 11 April 2016; accepted for publication 26 May 2016)

Abstract. The goal of the present study was to determine the influence of the ultraviolet fluorescence of cocoons, the hybrid, the sex and the interaction among them on the sericin content in silk threads. The study was performed with 3 di- and 2 tetra-cross silkmoth (Bombyx mori L.) hybrids, differentiated in three groups – with violet, intermediate and yellow fluorescence of the cocoons. The examined factors had a significant effect (p≤0.001) on the sericin content. The highest sericin content was detected in the silk threads of the violet-fluorescent and the lowest – in the yellow-fluorescent group. The analysed di-hybrids were distinguished by better characteristics in terms of sericin content, compared to the tetra-hybrids, most obvious for the yellow-fluorescent fraction.


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.


Breeding and agrotechnics of rape (Brassica napus L.). Winter rape – distribution, cultivation and investigation in Bulgaria

Oilseed rape (OSR) or rapeseed – Brassica napus L. is the most important plant of genus Brassica, grown for its oil content. Breeding of new rape varieties without eruc acid content (“0” type) and low-glucosinolytic content (“00” type) is a prerequisite for the cultivation of this crop in more countries and on increasingly larger areas. The recent gradual re-introduction of rapeseed in our country turned it into a successful crop. The potential of the introduced winter and spring rape varieties was investigated. The technology for new varieties and hybrids grown in Europe and worldwide was studied and improved. New initial material was collected and eaxamined as a basis for the resumed breeding of rapeseed in Bulgaria. The research work was directed towards developing parental forms and using heterosis in rapeseed.

Breeding and agrotechnics of rape (Brassica napus L.). Winter rape – distribution, cultivation and investigation in Bulgaria

M. Hristova-Cherbadzi, G. Georgiev