Bc INSTITUTE FOR BREEDING AND PRODUCTION OF FIELD CROPS
d.d. Zagreb, Marulicev trg 5/I, 10 000 Zagreb, Croatia.
Rade Mlinar and Ivica Ikic.
Introduction. Past investigations on the productive value of a wheat cultivar focused primarily on proving productivity. To get a clear picture of the entire economic value of a cultivar, investigating stability of certain traits and adaptability to different growing conditions is a necessity (Vasilj and Milas 1981; Surlan-Momirovic et al. 1990). The Bc Institute regularly investigates crucial traits comtributing to wheat yield under different environments, such as cultural practices, fertilizer application and rate, protection planting date and rate. We wanted to determine the variability of some important quantitative traits of the Bc wheat cultivars in comparison with Zitarka, the standard cultivar, and to identify superior genotypes with wide adaptability.
Materials and Methods. Investigations were conducted in field trials in 2000-01, 2001-02, and 2002-03 at Aagreb (Botinec). In all 3 years, plants was completed by the second half of October at a planting rate of 750 viable kernels/m2. Cultivars from different selection cycles were planted in five replications following a random block design with a basic plot size of 5 m^2^. Trials were conducted under production conditions and total fertilizer application was 155 kg/ha N, 100 kg/ha P2O5, and 150 kg/ha K2O. Table 1 lists the winter wheat cultivars tested.
| Cultivar | Developed by | Year of registration | Pedigree |
|---|---|---|---|
| Sana | Bc Institut d.d. | 1983 | Mura x CI14123 X BC-2413/72 |
| Zitarka | Poljop. Inst. Osijek | 1985 | OSK-6.30/20 x Slavonka x H-68 OSK-154/19 x Kavkaz |
| Marija | Bc Institut d.d. | 1988 | Bc-4527/68 x Kavkaz x Bc-1971/70 |
| Tina | Bc Institut d.d. | 1993 | Sana x Gala |
| Patria | Bc Institut d.d. | 1994 | Odesskaya-51 x ZG IPK 82 10 x GK-32-82 |
| Mihelca | Bc Institut d.d. | 1995 | Bc-1325/78 x SO-1065 |
| Zdenka | Bc Institut d.d. | 1996 | Beauchamp x BC-2557/83 |
| Liberta | Bc Institut d.d. | 1997 | M-441-1 X Drina x Bc-167/86 |
| Aura | Bc Institut d.d. | 1997 | 434 K-4CM x 7903-93-1 |
| Concordia | Bc Institut d.d. | 1998 | Bc-186/82 x Castan |
Results and Discussion. Grain yield. The average yield for all cultivars during 3 years of investigation was 5,796 kg/ha. The highest average yield was obtained in 2001 (7,254 kg/ha), a year which favored wheat growth, and the lowest yield (3,088 kg/ha) in the extremely dry environment in 2003. Range of variation was 4,166 kg. The highest yield of all cultivars was Liberta (8,239 kg/ha), which was the highest yielding cultivar on average (6,217 kg/ha; coefficient of variation was 32.3). Liberta was followed by Mihelca (5,943; 34.3), Tina (6,053; 35.5, Marija (6,023; 30.0), Patria (6,012; 28.2), Sana (5,985; 35.5), Zdenka (5,943; 35.0), Aura (5,842; 32.4), Zitarka (4,928; 36.9), and Concordia (4,866; 34.7). These results show that there are genetic differences in yield potential among the tested lines. Relative variability indicates more clearly the differences among the cultivars; the highest value for all 3 years was for the check cultivar Zitarka. Patria, Marija, and Liberta all had low relative variability, but standout with regards to their high productivity and stability, making them suitable for growing under different production conditions. Because of their performance during our trails, we believe that Mihelca and Tina can successfully only be grown under conditions that do not differ substantially from those in Botinec.
1,000-kernel weight. Greatly influenced by environment, 1,000-kernel weight averaged 39.58 g over all cultivars and years, the range between years was 9.63 g. The 1,000-kernel weight of all cultivars were sensitive to agroecological factors. Mihelca had the highest 1,000-kernel weight at 46.12 g, followed by Liberta (42.66 g) and Tina (42.48 g). Tina and Mihelca also had low relative variabilities of 7.95 and 9.79, respectively, unlike Liberta with a relative variabiligy of 15.07 for 1,000-kernel weight.
Plant height. Because tall cultivars are more prone to lodging, height is an improtant characteristic. Plant height determines agroecological conditions suitable for an individual cultivar. We discovered considerable differences in plant height among the tested cultivars and over years. The overall average was 75 cm; the variation between years was 39 cm. Mihelca and Patria were the tallest (80 cm), followed by Liberta (78 cm) and Aura (76 cm). The height of the other lines was similar to that of the check Zitarka (70 cm). Variability among repetitions was highest for Tina and Libert and lowest for Zdenka.
Sedementation. As an indirect index of wheat baking property, the sedementation value was lowest in 2001 at 30 ml. This year saw the highest yields. A higher value, 38 ml, was measured for the 2002 and 2003 test years, giving a range of 8 ml. The difference between the cultivar with the highest sedimentation value, Zdenka (54 ml), and the lowest, Patria (24 ml), was 30 ml. A high sedimentation value also was found in Aura (51 ml). Zdenka and Aura were developed in a more recent cycle of wheat breeding at the Bc Institute. During the 3-year period, Zitarka and Sana has the lowest variability; Concordia the greatest (24.3) (Fig. 2.).
Conclusion. Based on obtained yields and variability parameters, development of wheat cultivars that can meet both criteria of yield capacity and stability seems to be possible.
References.
Slobodan Tomasovic, Rade Milnar, Ivica Ikic, and Kristijan Puskaric.
Winter wheat breeding at the Bc Institute in Zagreb is based on developing high-yielding genotypes with wide adaptability and high plasticity under different agroecological conditions. In addition to developing a highly productive and stable genotypes, improved quality of grain and flour also have been incorporated. This work has resulted in the winter wheat cultivars Zdenka, Mihelca, and Aura.
Rheological analyses were conducted by the companies of PIK Vinkovci d.d., Ljudevit Posavski d.d. Sisak, and Podravka d.d. Koprivnica in 2002. The results prove that these are high-quality winter wheat cultivars that fully meet the needs of the milling and baking industry. Farinogram and extensogram values are given for each of the three cultivars; Zdenka (Table 2 and Fig. 1A), Mihelca (Table 3 and Fig. 1B), and Aura (Table 4 and Fig. 1C). These three winter wheats are first quality class and belong to the A1 and A2 quality groups. These results indicate that with the well-conceived breeding work at the Bc Institute, the new cultivars meet or surpass the qualty level of foreign improvers.