One of the targeted environments of the barley breeding program of the International Center for Agricultural Research in Dry Areas (ICARDA) are the highlands of Turkey, Iran, Central Asia and Caucasus, where cold tolerance plays an important role in stabilizing barley yields.
In 1998 the breeding efforts to improve cold tolerance, conducted in collaboration with NARS, were targeted to find an acceptable compromise between the desirable traits of spring types (earliness, good early growth vigor, long straw, drought tolerance) and the cold tolerance of winter barley. We followed two avenues: a) developing winter barley with good early growth vigor and resistance to drought; b) improving the cold tolerance of spring barley, planted in autumn.
One of the components of the collaboration is the exchange of germplasm (landraces, segregating populations, fixed lines, and improved sources of desirable agronomic traits). The evaluation of cold tolerance was done in natural environments in Turkey and Iran, and under controlled conditions in Krasnodar (Russia) and at ICARDA. In different nurseries many lines were identified with high level of frost tolerance: If/A//Barsoy/Ri, VA 92-42-46, 308/80M1, Wysor, Radical/Birgit, Dundy, K-253, NE 89747, K-247/Vavilon, K-88M1 and others. Among them there are early lines and genotypes with a very good early growth vigor.
The second approach resulted in developing new germplasm very similar to spring types, but with increased cold tolerance. In the three sets of the international spring barley yield trials (ISBYT-MRA-98, ISBYT-LRA-C-98, ISBYT-LRA-M-98) there were lines with the desirable characteristics. Especially valuable material has been found in the ISBYT-MRA-98, where the most cold tolerant lines proved to be on the top in grain yield due to good lodging resistance at Tel-Hadya (ICARDA headquarters) with the yield level of 4-5 t/ha (Table 1).
The depth of underground crown node is a trait very closely related to winter hardiness. Every centimeter of soil gives 1-3 o C protection against frost in the crown node. To study this character, 460 barley entries from advanced nurseries and crossing block were planted in the field at the fixed depth of 8 cm. The measurements started at tillering, when it is easy to measure the underground internode length. We found that it is indeed possible to measure the depth of the crown node also at stem elongation, and even after maturity, if dry plants are handled carefully.
* V. Shevtsov, S. Ceccarelli, S. Grando, - ICARDA, Aleppo, Syria; M. Tahir - Iran/ICARDA Project, Tehran, Iran; H. Tosun - ICARDA /Turkey Project, Ankara, Turkey; R. Premakumar - Uniform Winterhardiness Barley Nursery, Beltsville, USA
| Name | Traitsa | ||||
|---|---|---|---|---|---|
| GH | GV | CD | LD | Yield, kg/ha | |
| A.Aswad (check) | 4 | 3 | 2 | 5 | 3694 |
| WI 2291 ( improved check) | 1 | 1 | 2 | 5 | 4194 |
| Assala-04 (improved check) | 4 | 2 | 3 | 2 | 4520 |
| Aths/Lignee686//Hml-02/… | 5 | 2 | 1 | 1 | 5016 |
| 5604/1025//Arabi Abiad/3/Hml… | 3 | 1 | 1 | 1 | 4864 |
| WI2291/Bgs//WI2291/Roho | 2 | 2 | 1 | 2 | 4660 |
| LSD 0.05 | 360 | ||||
a
GH = growth habit (1 = erect, 3 = intermedium, 5 = prostrate); GV = growth vigor (score: 1 = very good, 3 = moderate, 5 = very poor); CD = cold damage in the field (score: 1= no damage, 3 = moderate, 5 = severe); LD = lodging (score: 1 = very low, 3= moderate, 5 = severe).
There is a large genetic variation for this trait, which varies from 2.2 cm to 7.1 cm. The majority of the lines tested formed the tillering node at the depth of 3.0 cm. Some genotypes such as Dictoo, ICB 101302, mutant 26M8, Rostov-55, have a very deep crown node, from 5.5 to 6.8 cm.
Table 2. Promising winter barley varieties and lines with deep crown nodes
| Name | Cold tolerance (%)a | Depth of crown node (cm) | Tillers number | Leaf length (cm) b | Grain yield per plot, (gr) |
|---|---|---|---|---|---|
| Rihane-03 - check | 5.2 | 3.2 | 2.8 | 25.5 | 1100 |
| Tokak - check | 40.2 | 3.6 | 5.6 | 21.0 | 520 |
| Radical - check | 80.6 | 3.7 | 3.8 | 19.5 | 680 |
| Kearney | 100 | 5.1 | 2.0 | 21.5 | 440 |
| Dictoo | 100 | 6.1 | 2.0 | 17.5 | 390 |
| NE 93 760 | 100 | 6.7 | 1.6 | 17.2 | 760 |
| NE 93 747 | 100 | 6.2 | 2.2 | 18.3 | 720 |
| Rostov-55 | 75.4 | 6.1 | 2.4 | 14.5 | 810 |
| ICB 101 302 | 60.2 | 5.8 | 6.0 | 22.3 | 660 |
| Plaisant/Novator | 57.6 | 5.8 | 2.4 | 19.6 | 780 |
| Baluchistan/Cougar | 50.3 | 4.1 | 2.8 | 18.3 | 1160 |
| LSD 0.05 | 8.7 | 0.4 | 56 |
a
frost tolerance in percentage of survival plants after freezing in chambersb
leaf length at the beginning of the stem elongation stage.The American lines NE 93760, NE 93 747, Dictoo (from the Uniform Winter Hardiness Barley Nursery), and the Russian variety Rostov-55 combine very deep crown nodes with high level of frost resistance. This makes them extremely valuable for the improvement of winter hardiness in barley (Table 2).
Many of these lines are six-rowed winter type, and need a long period of vernalization. They possess low tillering capacity and very poor initial growth vigor. But some of them, such as Baluchistan/Cougar, combine a deep tillering node with traits responsible for the adaptation and productivity. The two-rowed line, ICB 101 302, possesses good cold tolerance and large grain size. Even some spring barley lines from advanced trials, targeted for zones with warm climate, form the crown node deeper than 4 cm (Table 3).
Table 3. Characteristics of spring barley lines with deep crown node.
| Name | Cold tolerance (%)a | Depth of crown node (cm) | Tillers number | Leaf length (cm) b | Row type |
|---|---|---|---|---|---|
| Rihane-03 (check) | 5.2 | 3.2 | 2.8 | 25.5 | 6 |
| Tokak (check) | 40.2 | 3.6 | 5.6 | 21.0 | 2 |
| Radical (check) | 80.6 | 3.7 | 3.8 | 19.5 | 6 |
| SLB 31-24 | 65.3 | 4.4 | 5.8 | 30.0 | 2 |
| SLB 32-39 | 56.6 | 5.2 | 5.8 | 26.0 | 2 |
| H.spont.41-3/Tadmor | 20.2 | 5.8 | 3.6 | 29.0 | 2 |
| H.spont.41-3/SLB 39-39 | 10.3 | 5.3 | 4.0 | 22.5 | 2 |
| Arar/H.spont.19-15/Arta | 20.8 | 5.0 | 3.4 | 31.0 | 2 |
| Arar/H.spont.19-5/Harmal | 45.3 | 5.2 | 3.8 | 27.5 | 2 |
| Anadolu86//Arar/A.Aswad | 50.2 | 4.1 | 5.4 | 34.5 | 2 |
| CI 07117-/Deir Alla//Badia | 70.4 | 4.1 | 5.6 | 29.0 | 6 |
| LSD 0.05 | 8.7 | 0.4 |
|
a
frost tolerance in percentage of survival plants after freezing in chambersb
leaf length at the beginning of the stem elongation stage.These results indicate that the trait is independent from other agronomic traits, and that it is possible to find good combinations of deep crown node and other agronomic characters, when data of lines with crown depth of 4-5 cm are analyzed. The correlation coefficient between the depth of crown node and the early growth vigor recorded as leaf length before the stem elongation was r = 0.07, while with frost tolerance was r = 0.24. These sources of cold tolerance are widely used as parents in crosses to generate segregating populations targeted for Turkey, Iran, Central Asia and Caucasus.