**5. Breeding of wheat quality in Bulgaria – Steps, drawbacks, prospects**

Breeding of new varieties with good quality has always been on the attention of the breeding programs in Bulgaria (Boyadjieva et al., 1999; Panayotov et al., 1994; Rachinski, 1966; Stoeva & Ivanova, 2009). Combining high yield and quality in wheat is a challenge for the contemporary breeding as it is connected with many obstacles with different nature (Baenziger et al., 2001; Dencic et al., 2007; Eagles et al., 2002; Trethowan et al., 2001). Analysis of wheat quality begins with studying the initial material (Tsenov et al., 2010c). When foreign samples are received they are study for three years for a set of quality indices. Those with high levels are included in hybridization programs especially if they show high yield potential, stress tolerance, disease resistance. The basic foreign parent components for hybridization are from breeding centers with traditions and excellent achievements in breeding for wheat quality (table 9).

The quality of Bulgarian wheat varieties is based on the widespread use of variety Bezostaya 1 and other Russian and Ukraine sources (Panayotov & Kostov, 2007; Todorov et al., 1998; Tsenov et al., 2010b). During the last years samples with different origin are widely used as they possess high level of productivity combined with high end-used quality. The quality analysis during the breeding process is made according the scheme described in the table 10.

The beginning of quality analysis of the breeding lines is in the screening nursery. The main tests in this unit are sedimentation value of the flour and grain protein content. Quality index of each line and quality standard varieties is calculated by these two parameters. These indices are defined as they possess high and positive correlation with the main parameters, connected with the strength of flour and dough (Bona et al., 2003, Dacheva & Boydjieva, 2002).


Table 9. Origin of the initial breeding material for wheat quality



\* Quality index=Sedimentation/Protein content

426 Genetic Diversity in Plants

Wheat growing depends on environments although the right technologies and new varieties can manage to lower this dependence. That's why it is valuable to select varieties which give

Breeding of new varieties with good quality has always been on the attention of the breeding programs in Bulgaria (Boyadjieva et al., 1999; Panayotov et al., 1994; Rachinski, 1966; Stoeva & Ivanova, 2009). Combining high yield and quality in wheat is a challenge for the contemporary breeding as it is connected with many obstacles with different nature (Baenziger et al., 2001; Dencic et al., 2007; Eagles et al., 2002; Trethowan et al., 2001). Analysis of wheat quality begins with studying the initial material (Tsenov et al., 2010c). When foreign samples are received they are study for three years for a set of quality indices. Those with high levels are included in hybridization programs especially if they show high yield potential, stress tolerance, disease resistance. The basic foreign parent components for hybridization are from breeding centers

The quality of Bulgarian wheat varieties is based on the widespread use of variety Bezostaya 1 and other Russian and Ukraine sources (Panayotov & Kostov, 2007; Todorov et al., 1998; Tsenov et al., 2010b). During the last years samples with different origin are widely used as they possess high level of productivity combined with high end-used quality. The quality analysis during the breeding process is made according the scheme described in the table 10. The beginning of quality analysis of the breeding lines is in the screening nursery. The main tests in this unit are sedimentation value of the flour and grain protein content. Quality index of each line and quality standard varieties is calculated by these two parameters. These indices are defined as they possess high and positive correlation with the main parameters, connected

**5. Breeding of wheat quality in Bulgaria – Steps, drawbacks, prospects** 

with traditions and excellent achievements in breeding for wheat quality (table 9).

with the strength of flour and dough (Bona et al., 2003, Dacheva & Boydjieva, 2002).

Dough properties

Bulgaria **\* \* \* \* \***  Romania **\* \* \***  Serbia **\* \***  Turkey **\* \* \***  Odessa, Ukraine **\* \* \* \* \*** 

Mironovka, Ukraine **\* \* \***  Ktrasnodar, Russia **\* \* \* \*** 

Argentina **\* \* \*** 

Gluten properties

Bread making End-use quality

high quality in different environments.

Country Grain

properties

Harkov, Ukraine **\* \* \*** 

Nebraska, USA **\* \* \***  Oklahoma, USA **\* \* \***  Texas, USA **\* \* \***  Australia **\* \***  Canada **\* \*** 

Table 9. Origin of the initial breeding material for wheat quality

Table 10. Quality indices, used for breeding in the separate trial units

In the next trial units (PYT, CYT) the analysis extend and cover almost all aspects of quality of grain, flour, dough and bread. Along with this an analysis is made to determine the allelic diversity of the lines. At least three year data from CYT, which is the last level of screening of breeding materials, are needed in order to be able to assign each line in the following quality group: A – strong wheat; B – medium and C – wheat with soft endosperm (figure 4).

In the yield trails of Executive Agency of Variety Testing, Field Inspection and Seed Control (EAVTFIS) the candidate-varieties are also testing in these three groups at least 2 or 3 years. Each group has specific standards for comparison.

Fig. 4. Bread-making quality groups

The evaluation and selection for quality is associated with many difficulties from different nature. They can be determined as follows:


## **6. Conclusions**

As a result of a nearly half a century breeding in Dobrudzha Agricultural Institute 26 varieties from the first quality group are created. This is nearly one third of the entire variety list. The massive usage of variety Bezostaya 1 in the breeding programs direct or indirect narrowed the genetic diversity of the materials and to some extent unified their glutenin and gliadin spectra. The efforts to include foreign initial materials in hybridization, with alleles with good influence over the wheat quality, will probably be rewarded in the near future.

A breeding progress is determined for almost all the indices, defining end-use quality in wheat. The group of high quality wheat varieties has greater progress compared to all varieties irrespective of the indices.

Different factors influence on the wheat quality and on the expression of different indices. The knowledge of the nature and direction of the effect of these factors is valuable for predicting to some extend the performance of wheat varieties in certain growing conditions. Most of the Bulgarian varieties show moderate stability at different environments. But the results for the individual varieties and their indices are not unidirectional and therefore when selecting a variety for mass production it is necessary to consider the purpose for its cultivation, the potential of the given variety and its ability to realize this potential with stability and adequacy.

#### **7. Acknowledgment**

The authors give their acknowledgments to all colleagues from the different laboratories for their help in determine different aspects of wheat quality.
