Correlations between grain yield and related traits in winter wheat under multi-environmental traits

  1. Tsenov1*, T. Gubatov1, I. Yanchev2


1Department of Wheat Breeding and Technology, Agronom Breeding Company, 9300 Dobrich, Bulgaria

2Department of Plant Science, Faculty of Agronomy, Agricultural University, 4000 Plovdiv, Bulgaria

(Manuscript received 7 August 2020; accepted for publication 29 October 2020)

Abstract. In a series of field trials, a database of quantitative traits associated with winter wheat grain yield has been collected. The aim of the present study is to determine the relationships between the winter wheat (Triticum aestivum L.) traits of productivity in environments causing the maximum possible variation of each of the traits. In order to determine the correlations between the quantitative characters studied, all possible statistical methods have been applied (regression analysis, PCA, Multiple Correspondence analysis), which complement each other. It was found that the nature of the correlations between traits depends to a large extent on the methods for their evaluation. There are high and significant correlations between grain yields and the grain number per spike (weight of grain per spike and number of grains per m2) even under strong genotype by environment interaction of all the traits in trails. The established results are related to possible options for increasing winter wheat grain yield by breeding.

Statistical analysis of genetic diversity using faba bean landraces database

N. Velcheva*, S. Petrova

Agricultural Academy, Institute of Plant Genetic Resources K. Malkov, 2 Druzhba Str., 4122 Sadovo, Bulgaria

(Manuscript received 20 May 2020; accepted for publication 24 July 2020)

Abstract. Evaluation of genetic diversity among landraces could be an invaluable aid related to the sustainable use of ex situ collections. Statistical methods are currently available for analysis of databases from investigation of stored germplasm. Faba bean (Vicia faba L.) is a self-pollinating with high percentage of foreign pollination legume crop with a great importance for food and forage due to its high protein content as well as the important role in soil fertility and nitrogen fixation. The local populations are well adapted to specific agro-climatic conditions in the growing areas and are a rich initial material for the breeding programs. The purpose of this study is to establish the genetic diversity of 21 Bulgarian faba bean landraces by important traits in order to review the current potential of conserved germplasm for its sustainable use. All genotypes, included in the study, are collected from expeditions in the country, recorded in the National Register for Plant Genetic Resources and long term stored at the National Genebank. They are characterized according to the International Faba Bean Descriptors. The cluster analysis results show a high genetic diversity in the collection and the variability of each studied trait is presented. The factor analysis, which complements the cluster analysis, gives a reason to group the genotypes with their features into groups that have a breeding value. Genetic diversity in the studied collection has been identified and some of the landraces could be included in future breeding programs.

Contribution of Parastagonospora nodorum to the leaf and glume blotch of durum wheat in Bulgaria

Nedyalkova1, Z. Stoyanova2, R. Rodeva2*

1Field Crop Institute, Agricultural Academy, 6200 Chirpan, Bulgaria

2Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str.,

1113 Sofia, Bulgaria

(Manuscript received 12 February 2020; accepted for publication 4 May 2020)

Abstract. Parastagonospora nodorum is an important necrotrophic fungal pathogen causing leaf and glume blotch of wheat worldwide. The disease can result in significant losses in grain yield and quality. The purpose of the current investigation was to estimate the occurrence of P. nodorum as a foliar and ear pathogen of durum wheat and disease severity on a set of cultivars under natural infection. Field experiments were performed at two locations (Sofia and Chirpan) in the period 2010-2017. Twelve winter cultivars of durum wheat were involved in the study. P. nodorum was not found at both locations in 2010 and 2011. Thereafter the pathogen was recorded on the leaves of durum wheat in Sofia every year except 2013. Symptoms included chlorosis and necrosis of the leaf tissue. The strongest manifestation of the disease was observed in 2016 and especially in 2017. In Chirpan leaf blotch was noticed only in 2 out of 8 growing seasons. The ear infection led to development of dark brown patches on the glumes, which later became purple-brown. These symptoms were noted in Sofia in 2014, 2016 and 2017. In Chirpan, glume blotch of studied cultivars was recorded in 2017 but in the previous year the symptoms were widely observed on some genotypes among the initial breeding material of durum wheat. In the present investigation P. nodorum caused leaf and glume blotch only. Symptoms on stems, nodes and leaf sheaths were not noted at both locations. The 12 cultivars under study differed in their susceptibility to leaf and glume blotch. The leaf symptoms caused by P. nodorum were recorded on all cultivars, but were more pronounced on Zvezditsa, Deyana and GK Bétadur. The glume blotch was more noticeable on Vazhod. The results of this multiyear research showed that although P. nodorum did not appear every year, the pathogen could contribute to the leaf and glume blotch of durum wheat under conditions favourable for disease development. The evaluation of cultivars demonstrated encouraging preliminary results. Several cultivars showed lower disease severity on flag leaf and no or little infection on the ear. They deserve further studies on resistance to P. nodorum.

Association between physiological parameters and yield in Triticum aestivum L. genotypes under rainfed conditions

İ. Öztürk

Trakia Agricultural Research Institute, Edirne, Turkey

(Manuscript received 22 July 2019; accepted for publication 6 April 2020)

Abstract. The purpose of the study was to assess the relationships between physiological parameters and grain yield of different bread wheat genotypes. In the present research a total of 25 bread wheat genotypes were tested during the 2016-2017 seasons under rainfed conditions. The experiment was conducted in a randomized complete blocks design with four replications. Grain yield, days of heading, plant height, biomass (NDVI) from GS25 up to GS85 growth stage, chlorophyll content (SPAD) during the heading stage, canopy temperature (CT) at GS60 and GS75 growth stages, and glaucousness were investigated. The results of variance analyses showed that there were significant differences (p<0.01) among genotypes for yield. The mean grain yield was 7948 kg ha-1 and yield ranged from 7033 kg ha-1 to 8759 kg ha-1, the highest grain yield performed by TE6744-16 line. According to the results, significant differences among cultivars in terms of plant height, days of heading, biomass, chlorophyll content, canopy temperature, glaucousness were found. TE6627-6 line had the highest chlorophyll content and also, chlorophyll content positively affected grain yield. Canopy temperature is generally related to yield under drought stress condition in bread wheat. In the study early maturing (days of heading) genotypes had lower canopy temperature. An increase in biomass after the heading phase has positively affected grain yield. In the study, no correlation was found between grain yield and biomass at GS25 and GS45 growth phase. There was a negative correlation between glaucousness with biomass at GS60, GS75 and GS85 growth phase. These results showed that physiological parameters such as biomass (at GS75 and GS85), canopy temperature (at GS60 and GS75), and chlorophyll content (at GS60), and glaucousness could be used for selection parameters under rainfed conditions for yield in bread wheat.

Genotype x environment interaction analysis of Triticum aestivum L. for yield components

İ. Öztürk1*, K.Z. Korkut2

1Trakia Agricultural Research Institute, Edirne, Turkey
2 Department of Field Crops, Faculty of Agriculture, Namık Kemal University, Tekirdağ, Turkey

(Manuscript received 5 December 2019; accepted for publication 26 February 2020)

Abstract. Genotypes performance changes due to environmental pressures or stresses and differences in their ability to adapt to the stress factors. Drought is the main abiotic stress factor affecting bread wheat yield and yield component. The experiment was carried out in the experimental field of Trakia Agricultural Research Institute, Edirne (Turkey), in 2008-2009 and 2009-2010, and 15 wheat genotypes were planted in RCBD in a split-plot with three replications. The main plots were assigned to five moisture regimes, which included 3 drought stress environments, one non-stress and one non-treatment environment. Principal component analysis (PCA) and cluster analysis were used to determine genotypes environment interaction. Grain yield, biological yield, harvest index, spike number per square meter, kernel and spikelet number per spike, length of spike and plant height were investigated. PCA indicated that the first (46.31%) and second (25.32%) components justified 71.63% of variations in the investigated yield parameters of the genotypes. Based on GGE biplot results, Kate A-1 and Tekirdağ genotypes were determined as the most stable cultivars for grain yield. Mean values of the genotypes varied between 3830-6583 kg ha-1 for grain yield, 20170-25394 kg ha-1 for biological yield, 68.6-110.9cm for plant height, 30.2-38.3 for kernel number in spike, 328.8-486.6 for spike number per square meter and 6.57-9.17cm for spike length. Clusters I and II were more clearly separated. In the first group of clusters 6 genotypes are located including one line and five cultivars. In the second group of clusters 8 genotypes are located including five advanced lines and four cultivars.

Karyotype variability of the Ukrainian Mountain-Carpathian sheep breed

K. Typylo*

Institute of Animal Breeding and Genetics nd.a. M.V. Zubets of National Academy of Agricultural Sciences, Chubinsk Boryspil district, Kyiv region, 08321, Ukraine

(Manuscript received 5 September 2019; accepted for publication 25 November 2019)

Abstract. The main purpose of this work was to describe the karyotype variability of the Ukrainian Mountain-Carpathian sheep breed. Cytogenetic studies were carried out on a group of 25 sheep from that breed. The cultivation of lymphocytes, preparing the cytogenetic samples, classification and registration of chromosome aberrations were held using conventional methods. It was established that the number and structure of the chromosomes of sheep of the Ukrainian Mountain-Carpathian breed correspond to the norm typical for this species of animals. Chromosomal variability of the studied population includes 19.22% of numerical and structural aberrations. By the number and structure of the chromosome set the Ukrainian Mountain-Carpathian sheep breed does not differ from other breeds of sheep. Accurate identification of individual chromosomes with routine coloring allows using cytogenetic studies in breeding practice in sheep breeding.

Heterosis manifestations for spike productivity traits in durum wheat

R. Dragov*
Field crops institute (FCI), 6200 Chirpan, Bulgaria
(Manuscript received 5 September 2019; accepted for publication 18 October 2019)

Abstract. The aim of the study is to investigate the heterosis manifestations in durum wheat for quantitative traits related to spike productivity. Diallel cross includes five modern varieties of durum wheat: Victoria (BG), Deni (BG), Superdur, Progress (BG), Predel (BG). The heterosis manifestations of the ten crosses are traced for the traits: spikelet number per spike, number of kernel per spike, grain weight per spike and thousand kernel weight. The experiment is conducted in the 2014-2016 period in the experimental field of FCI- Chirpan. Standard technology for the cultivation of durum wheat is applied. The trials are organized in a randomized block design with three replications. Of each replication 30 plants are randomly picked and harvested for biometric analysis. The mean values by years from the F1 spike biometric measurements are included in the statistical analysis to determine the mid parent and better parent heterosis. For spikelet number per spike, seven crosses show high parent heterosis in the first year, four in the second and six in the third year. In all years, hybrids with a variety of Victoria have more spikelet number per spike and show better parent heterosis. For the trait kernel number per spike it is observed that combinations with Deni variety in most cases have better parent heterosis. In all years, the cross Superdur x Predel indicates high parent heterosis for this trait. For grain weight per spike most of the combinations exhibit high levels of better parent heterosis. When the Deni variety is used as female parent, all hybrid combinations show high levels of heterosis for the trait grain weight per spike. In regard to the thousand kernel weight different heterosis levels are observed, with only negative values in the first year. In the other two years in hybrid combinations there is positive heterosis in one year and negative in another year. The participation of the Deni variety in hybrid combinations leads to better parent heterosis for this trait. The data allow the use of these crosses directly in the breeding of durum wheat to increase individual traits and/or increase productivity.

Assessment of bread wheat (Triticum aestivum L.) genotypes based on their agronomic characters and tolerance to biotic stress

İ. Öztürk1*, A. Şen2, T.H. Kılıç1, Ş. Şili1

1Trakia Agricultural Research Institute, Edirne, Turkey
2Department of Biology, Faculty of Science, Istanbul University, Istanbul, Turkey

(Manuscript received 15 April 2019; accepted for publication 10 September 2019)

Abstract. The aim of the study was to investigate the occurrence and severity of biotic stress factors, quality and agronomic parameters and its effect on yield and quality character of wheat genotypes. The experiment was conducted at Trakia Agricultural Research Institute, Edirne experimental area, during 2013-2015 cropping years. Grain yield, days of heading, plant height, 1000-kernel weight, test weight, protein ratio, leaf rust, stripe rust, Septoria leaf spot and relationship among these parameters were investigated. Based on a two years data, apart from protein content, other parameters showed significant difference (p<0.05). When compared to the mean yields in both cropping years, the genotypes Gelibolu and BBVD-3, BBVD-4, BBVD-9 genotypes were determined the better-adapted genotypes under target environment. Cultivar Aldane and TCI011322-8 line was detected as very tolerant to leaf rust and stripe rust in both years under the infection of field condition. Aldane had higher protein ratio, 1000-kernel weight and test weight. Grain yield was positively correlated with test weight and negatively correlated with foliar diseases. A highly significant negative correlation was determined between grain yield and plant height in both growing years. Leaf rust and Septoria tritici leaf disease had negative effect on protein ratio in both years. There was a significant positive relation between 1000-kernel weight and test weight. Results of the study indicated that based on biotic stress factors BBVD-6, BBVD-7 and TCI011322-8 are promising lines that need to be improved a bit further.

Preservation and study of old local forms of the so called “vineyard peach” (Prunus persica L.) in the Shumen region, Bulgaria

  1. Vasilev1, S. Malchev2, A. Zhivondov2


1“Konstantin Preslavsky” University of Shumen, 115 Universitetska Str., 9700 Shumen, Bulgaria

2Fruit Growing Institute, 12 Ostromila Str., 4004 Plovdiv, Bulgaria


(Manuscript received 20 June 2019; accepted for publication 15 August 2019)


Abstract. During the period 2015-2017, scientific expeditions were conducted in the region of the town Shumen, located in the north-eastern part of Bulgaria, mainly around the village Madara where the concentration of natural forms derived from seedlings is the greatest. The purpose is to discover and research old local forms of the so called “vineyard peach” and to preserve them for possible future inclusion in breeding programmes to create new cultivars using more extended genepool. As a result, three forms of “vineyard peach” were selected from the local populations. The fruits of the three local forms are small and with primitive taste qualities but fit for human consumption. Two of the forms have white fruit flesh and one is with green. Two of the peach forms have vigorous growth, but one of the forms with white fruit flesh is of weak vigour. The three forms are spontaneous natural products obtained through long-term seed propagation. The trees are old but vital and without visual damage by diseases and pests, regularly bear fruits and have good annual growth despite competition from weeds, bushes and trees.

Relationships between milk yield, quality and coagulation properties with kappa-casein (к-CN) genotypes of Bulgarian Rhodope cattle breed

  1. Mehandzhiyski1, Т. Angelova2, D. Yordanova2, J. Krastanov2


1Research Centre of Livestock Breeding and Agriculture, 4700 Smolyan, Bulgaria

2Agricultural Institute, 6000 Stara Zagora, Bulgaria


(Manuscript received 12 June 2019; accepted for publication 10 August 2019)


Abstract. The aim of the present study was to establish the association between different к-CN genotypes with milk yield, quality and coagulation properties in dairy cows of Bulgarian Rhodope breed. For determination of milk proteins polymorphism and its relationship with individual coagulation properties of milk and its quality, 136 milk samples from Bulgarian Rhodope dairy cows reared in 4 farms were collected. The visit to the farms and the taking of the milk samples took place between May and June 2009. Animal milk is based on daily milking on the relevant control day of the current lactation. During the morning milking, 50mL samples were collected without preservative, stored in cooling bags and analyzed in the specialized lab at the Agricultural Institute, Stara Zagora by Computerized Renneting Metter. The evaluated parameters of milk coagulation properties were: rennet coagulation time (RCT, min); curd firming time (K20, min) and curd firmness (A30, mm). Milk proteins polymorphism was identified by tissue samples collection from 136 cows. To this end, specialized pliers and marks with a vial containing desiccant were used. With this technique, the tissue sample is obtained and sealed at the time of identification of the animal. After collection, tissue samples were shipped to the University in Padova, Italy for PCR-RFLP analysis. DNA was purified using a Maxwell®16 Tissue DNA purification kit (Promega) according to the manufacturer’s instructions. Data were analyzed using descriptive statistical analysis (SYSTAT 13). The results obtained give reason to the following conclusions: The highest milk yield was established in cows from the AH genotype – 16kg, whereas the lowest value was detected in cows from the BH genotype – 12.83kg. Homozygous cows from the BB genotype produced milk with the highest fat content – 5.11%, whereas heterozygous from the BH genotype: milk with the lowest protein content – 3.16%. The cows from the AH genotypes were outlined with the lowest milk fat and protein content. The longest rennet coagulation time (RCT) was observed in АА and АН genotypes, the longest curd firming time (К20) – in genotype AH, the highest curd firmness (А30) – in the milk of cows from the AB and BB genotypes.