Effect of short stature on agronomic characters of barley grown under different nitrogen rates

In the present study, different isogenic lines developed through introgression of three short stature genes using marker assisted breeding were evaluated with two nitrogen rates (80 and 120 kg/ha). Three isogenic lines carrying three short stature genes, and recurrent parents Tokak 157/37 and Baronesse were studied. The first gene was denso and it was transferred from cv. Triumph to Tokak 157/37. The second gene was hst3 transferred from cv. Steptoe to cv. Tokak 157/37. The third gene was eps2 and it was transferred from cv. Tadmor to cv. Baronesse. A field trial was carried out in Tokat Kazova region of Turkey. Time to heading, time to maturity, plant height, number of spikes per area, lodging, number of kernel per spike, 1000-seed weight, biological yield, seed yield, harvest index, test weight and protein content were determined. Significant differences were observed among the genotypes for all traits studied. Nitrogen fertilizer rates significantly affected the number of spikes per area, 1000-seed weight, test weight, protein content, biological and seed yield traits. denso gene introgressed into cv. Tokak 157/37 delayed time to heading and time to maturity for four and three days, respectively, increased the number of kernels per spike by 1.30, harvest index by 3.88 and protein content by 0.20%. On the other hand, denso gene reduced plant height by 21 cm, lodging by 31%, 1000-seed weight by 6.39 g, biological yield by 2.35 t/ha, seed yield by 0.30 t/ha and test weight by 1.69 kg. Number of spikes per area was not affected by denso. The second gene studied, hst3, decreased plant height by 8 cm, lodging by 16% while increasing 1000-seed weight by 4.79 g, test weight by 0.85 kg and harvest index by 1.42% when introgressed into cv. Tokak 157/37. Other traits were not influenced by hst3. When introgressed into cv. Baronesse, eps2 gene hastened time to heading by about 2.5 days and time to maturity by 2.0 days. This gene increased number of spikes per area by 92, seed yield by 0.59 t/ha, harvest index by 4.43%, test weight by 1.37 kg and protein content by 0.51%. This gene resulted in a 5 cm shortening in plant height, but did not affect other traits. In conclusion, denso gene resulted in a 21 cm reduction in plant height and consequently decreased the seed size and test weight. Thus, it could be useful for improving the lodging in feed barley for areas where lodging is severe. hst3 which resulted in a 8 cm reduction in plant height increased seed size and test weight, and therefore could be more appropriate for the improvement of malting barleys. Resulting in a 5 cm decrease in plant height, eps2 gene, which caused increases in number of spikes per area and test weight, could be used for the improvement of yield and quality of malting barley together for production areas where lodging is not severe. KEYWORDS: Nitrogen Fertilization, denso, eps2, Harvest İndex, hst3, Short Plant Stature, Lodging