Breeding assessment of new promising cotton lines

V. Dimitrova, R. Dragov

Field Crops Institute – Chirpan, 6200 Chirpan, Bulgaria

(Manuscript received 7 June 2021; accepted for publication 2 August 2021)

Abstract. Cotton breeding in Bulgaria is mainly aimed at improving the earliness, productivity and fiber quality of modern varieties. The creation of new genetic diversity is one of the basic prerequisites for the success of breeding programs. The aim of the study was to evaluate cotton lines obtained by intraspecific and remote hybridization combined with backcross technology, with a view to their most effective usage in selection. Twenty-three lines were included in competitive variety trials conducted during the 2014-2017 period. The averaged results showed that lines 550, 639, 641, obtained by remote hybridization, appeared to be very promising. These three lines were distinguished by the best combination of productivity, fiber length and fiber lint percentage, and by these three indicators they exceeded the standard variety Chirpan-539. A new cotton variety Aida (No. 457) was approved, which in seed cotton yield and fiber yield, and technological fiber properties surpassed the standard varieties Chirpan-539 for earliness and productivity and Avangard-264 for fiber quality. The candidate variety 535 continued the state variety testing. Two new candidate cotton varieties No. 550 and No. 553 were released. In the state variety testing the three candidate varieties confirmed their qualities. The obtained lines, distinguished by one trait or by a complex of qualities, enriched the gene pool of Bulgarian cotton.

Population status, breeding policy and perspectives for the development of the Danubian horse breed

  1. Vlaeva1, N. Lukanova 2, M. Popova3

1Sub-department “Horse breeding”, Department of Animal husbandry – Non-ruminants and other animals,

Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

2Institute of Animal Science, 2232 Kostinbrod, Bulgaria

3 Department of Animal Sciences, Agricultural University, 12 Mendeleev Str., 4000 Plovdiv, Bulgaria

(Manuscript received 12 June 2019; accepted for publication 22 July 2019)


Abstract. The population status and breeding policy of the Danubian horse breed were studied for a relatively long period, from 1953-2017. The study traced the change in population number of the breed in decades and by different categories of animals. The analyses show a strong reduction in the number of Danubian horses in all categories. The small number of newborn foals is associated with the lowering number of breeding mares especially after the 1980s. In the last decade, according to an officially published bulletin by the breeding organization on the other hand, there was an increase in the number of mares and stallions and inconsistent with that number of breeding horses, newly born foals. In a historical aspect, the breeding policy of the Danubian horse showed some interesting and unpublished so far facts. Those facts are related, on the one hand, with the origin of the mares that became founders of families and, on the other hand, with the use of stallions of different breeds for input of purebred animals.

Variation in the agronomic and morphological traits in spring barley

N. Dyulgerov, B. Dyulgerova*

Institute of Agriculture, 8400 Karnobat, Bulgaria
(Manuscript received 4 July 2017; accepted for publication 27 October 2017)

Abstract. The study was conducted to examine the variation in the agronomic and morphological traits in spring barley. For this purpose, 22 lines from the ICARDA High Input Barley Program for favorable environment and 3 check varieties (Rihane-03, VMorales and Veslets) were tested in an alpha-lattice design with two replications at the Institute of Agriculture – Karnobat, Bulgaria in 2014 and 2015 growing season. The traits days to heading, plant height, number of tillers per plant, flag leaf length, flag leaf width, spike length, awn length, peduncle length, spikelet number per spike, grain number per spike, grain weight per spike, 1000 grains weight, grain yield, powdery mildew (Erysiphe graminis f. sp. hordei), net blotch (Pyrenophora teres f. teres) and stripe rust (Puccinia striiformis f. sp. hordei) infection were studied. Significant differences between lines for all studied traits were found. The number of fertile tillers per plant was significantly positively correlated with grain yield. Lines expressed higher grain yields, shorter stem, better tolerance to net blotch and stripe rust than Bulgarian check variety Veslets were identified. These genotypes can, therefore, be used as parents for the improvement of spring barley.

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.


Genetic diversity in different accessions of oat (Avena sativa L.)

T. Savova1*, B. Dyulgerova1, G. Panayotova2

1Institut of Agriculture, 8400 Karnobat, Bulgaria
2Institut of Agriculture and Seed Science “Obraztsov chiflik”, 7000 Rousse, Bulgaria

Abstract. The objective of this study was to study genetic diversity among winter oat accessions by using multivariate analyses: hierarchical cluster and principal component (PC) analyses. The study was conducted in the Institute of Agriculture, Karnobat, during the period 2005 – 2011. Oat germplasm consisting of 25 genotypes was evaluated for length of vegetation period, winter resistance, lodging resistance, plant height, length of panicle, number of spikelets and grain in 1 panicle, grain weight per panicle,1000-grain weight. The Dunav 1 variety was used for comparison as a standard for winter oats. There was a significant genetic diversity among the studied accessions, which allows selection of appropriate parents with characters important for oat breeding. In the direction of early ripening the accessions: РА 7606-51, РА 7307-70 and NC 79-43; low stem: РА 7409-151, РА 7915-1342, РА 8019-1; lodging resistance: РА 7507-14, РА 7219-19, РА 7617-3460 may be included as suitable sources. The best combination of agronomically valuable traits was established for accessions: РА 7617-3658, РА 8014-1356 and РА 7603-7. Panicle length, number of spikelets and grain in the panicle, weight of grain in one panicle and 1000-grain weight were the important traits in differentiating the genotypes.


Study of chickpea seed size heredity (Cicer arietinum L.)

R.Sturzu*, T.Nistor, F.Bodescu, C.Melucă

Abstract. The hybridological study of five chickpea parental genotypes and their direct hydrids in F1 generation elucidated some aspects regarding the genetic control of seed size. The experimental results showed that into genetic control of the seed size, both additivity (gi) and dominance (l, li, lij) effects of genes, involved into heredity of this genetically quantitative trait, have been involved. They acted asa “partial dominance” genetic mechanism (H /D)1/2 = 0.82 and 1 Vr/Wr = 0.87 confirmed by the result of graphical analysis, too. The frequency of dominance genes was in excess vs. that of recessive ones. The dominant and recessive genes as well as the dominant and recessive alleles (H /4H 0.21) were symmetrically distributed among parents. The set of tested genitors can 2 1 = emphasize the presence of a gene or a dominant gene group of them closely associated, which obviously influence the tested trait (h2/H = 0.87). The heredity 2 coefficients for the tested trait had values of 0.72 in narrow and 0.99 in large one.


Crops from Cucurbitaceae in collection of the Maritsa Vegetable Crops Research Institute, Plovdiv – local cultivars and their application in breeding programme

N. Velkov*, V. Petkova

Abstract. Cucumber, watermelon, melon and squashes are species belonging to the Cucurbitaceae family. The breeding of these crops has long tradition in Bulgaria. The created old varieties of cucumbers, watermelons, melons and squashes are subject to variety maintenance in the collections of Maritsa Vegetable Crops Research Institute and have significant participation in the new breeding programs. In this paper the results from study regarding the assessment of genetic resources in Cucurbitaceae family (old local cultivars and wild species) are presented. Gene pool in cucumbers comprises twelve old varieties, including: long parthenocarpic type – three, salad – four, and small fruited type – five. Some of these varieties are involved in promising hybrid combinations. The melons were represented by three old local cultivars which are also included in the breeding scheme. In the collection of watermelons we maintain three old local cultivars and with squashes – two. The Lagenaria, Luffa and a number of wild species are of small importance for the agriculture but they are valuable sources of genetic plasma. The most typical peculiarity of all species from this family is the great polymorphism in respect to the flowering type, plant habit and fruit features. As a result of the performed study morphological, phenological and phytopathological evaluation of the available gene pool of Cucurbitaceae family was made using traditional and modern breeding methods with an emphasis on new breeding approaches.


Apricot breeding for resistance to Sharka

V. Bozhkova, S. Milusheva
Abstract. The Sharka disease caused by Plum pox virus (РРV) was found for the first time in Bulgaria more than 80 years ago and it is an endemic disease for our country, as is for all the East European countries. Like all plant viruses, PPV could not be controlled with treatments and that makes breeding of resistant cultivars and rootstocks a significant tool for limiting its spread. The investigation was carried out in the period 2009–2012 in the collection plantations of the Fruit-Growing Institute, Plovdiv in the frames of FP7 project of the EU „Sharka Containment (SharCo)”. The aim set in one of the work packages of the project was to carry out accelerated breeding activities of apricot cultivars resistant to Sharka by using MAS (marker-assisted selection). The hybridization programme included 24 parental combinations with 12 633 pollinated flowers and as a result 1661 hybrid stones (seeds) were obtained. The molecular marker analysis of the leaf samples from 39 hybrid plants obtained from 7 crossings showed that 8 of the hybrids contained a gene for resistance to PPV. Those were plants of the parental combinations ‘Harcot’ х ‘Lito’, ‘Lito’ х ‘SEO’ and ‘Harlayne’ х ‘Harcot’. Data showed that all hybrids obtained from crossing of two resistant cultivars (‘Lito’ х ‘SEO’) have a gene for resistance. If only one of the parental cultivar is resistant, part of the hybrids have gene for resistance to PPV and in our case it is 50% of all analyzed hybrids.


Аgrobiological characterisitics of wintering forms of foeniculum vulgare L.

The general agrotechnical characterization of fennel was done mainly in four areas: Growth rates – the earlier and simultaneous seed formation resulted in obtaining a high quality production with minimum loss of harvest. Of the observed plants 64% meet these requirements. The seed yield per plant is the most important indicator characterizing the economic qualities of the selected specimen. In the observed plants it varied over 7 times- from 13.6 to 97.2 g / plant. The essential oil content in seeds is a major quality indicator for fennel. The tested samples have a variation of nearly three times – from 2.1 to 6.1 percent. The content of anethole and fenchone in essential oil are conclusive indicators that show the viability of the observed samples. The discovery of plants with high levels of the undesirable constituent fenchone of 11-17% points to the hybrid nature of the observed samples. In the seminal progeny of successfully wintered plants there is one with economic indicators exceeding those of the Shumen variety, as a seed yield of 97.2 g /plant, essential oil content 6.2%, fenchone 0.99%, anethole 86%. These, however, cannot be sustainably inherited in the progeny.

Аgrobiological characterisitics of wintering forms of foeniculum vulgare L.

A. Dzhurmanski

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