CIMMYT/ICARDA/TURKEY International Winter Wheat Improvement Program-IWWIP
P.K. 39 Emek, 06511 Ankara, Turkey.
H.J.Braun *, M. Mergoum *, H. Ketata **, H. Aktas ***, A. Bahci
****, N. Bolat ****, L. Cetin ****, H. Ekiz ****, M. Keser ****,
and K. Yalvac ****.
* CIMMYT, ** ICARDA, *** Plant Protection Institute, Ankara, and
**** Cereal Improvement Program, Ministry of Agriculture and Rural
Affairs.
In the European part of Turkey, excessive rains in autumn of 1998 did not allow sowing of nearly 200,000 ha. The coastal areas had normal rainfall. The Central Anatolian Plateau and southeast Turkey suffered from severe drought, which reduced the wheat production to 16 x 10^6^ tons, compared to 21 x 10^^ tons in 1997-98 and the lowest figure during the last 10 years. Root and crown rots were widespread on the Central Plateau and in the Marmara and Thrace region. A severe yellow rust epidemic in Azerbaijan, Turkmenistan, Uzbekistan, and Tajikistan caused significant grain losses.
Forty two coöperators returned data for the 8th FAWWON (grown in 1998-99), and the final report has been distributed. Entries with the lowest scores for yellow and leaf rust are given in Table 1.
Yield data from 14 locations were returned by cooperators of the 3rd Elite Yield Trial for irrigated areas (3EYT-IRR) and by 18 coöperators of the 3rd Elite Yield Trial for rain-fed areas (3EYT-RF). Table 2 and Table 3 provide means for agronomic traits and disease scores. In both trials, local checks are mostly susceptible to yellow and leaf rusts, as shown by the high average scores for these two diseases.
Root, crown, or foot root rots are among the major diseases of wheat worldwide, particularly in the dryland areas of the WANA region. The occurrence and frequency of the causal agents vary regionally. The damage caused by these pathogens varies from year to year, as well as from field to field, depending upon the amount of inoculum present, cultural practices, soil, and climatic conditions. Root-rot diseases most often reduce seedling stand, yield, and grain quality. Root rots can be caused by one or several pathogens alone or in combination. The most commonly reported causal pathogens are C. sativus, F. culmorum, F. graminearum, and F. avenaceum.
Selection for resistant/tolerant cultivars is usually the most economic, sustainable, and environmentally sound way to control crop diseases. However, inadequate and inconsistent inoculation methods and lack of accurate and suitable techniques for disease evaluation have hindered screening wheat for root rot complex disease. During the last decade, several studies has been conducted in the WANA region to address this very complex disease that causes substantial yield losses for farmers in the region. Recently, the International Winter Wheat Improvement Program (IWWIP), involving the National Agricultural Research Institutes in Turkey and the international Centers of CIMMYT and ICARDA, decided to resume work on root rots. Hence, in the 1999-00 crop season, more than 1,500 wheat cultivars and advanced lines were inoculated artificially by root-rot pathogens and planted in Konya, Turkey, where root rot is observed frequently and will be evaluated and screened for resistance to this disease.
The bread and durum cultivars released in Turkey in 1997 and 1998 are listed in Table 4.
CUKUROVA UNIVERSITY, ADANA
Department of Soil Science and Plant Nutrition, 01330 Adana, Turkey.
I. Cakmak.
Zinc (Zn) deficiency is the most prevalent micronutrient deficiency in crop plants in Turkey, especially in Central Anatolia, which is the major wheat-growing area. The Zn-deficient areas in Turkey cover 14 Mha of cultivated land equivalent to 50 % of the cultivated area.
Wheats grown in Central Anatolia were found to be highly responsive to Zn fertilization. Relative increases in grain yield from Zn fertilization on different locations ranged between 5 to 550 % and had a mean of 43 %. The highest increases in grain yield (> 100 %) were found at locations where DTPA-extractable Zn concentrations are below 0.12 mg/kg soil. When wheat is sown in such soils without Zn fertilization, grain yields are extremely low and usually below 550 kg/ha. Soils containing < 0.3-0.4 mg Zn/kg soil DTPA-extractable Zn were found to be responsive to Zn fertilization, particularly in the case of durum wheats. Around 10 kg Zn/ha was adequate to grow wheat without yield depression on Zn-deficient calcareous soils.
Testing wheat cultivars on Zn-deficient calcareous soils in Central Anatolia showed the existence of substantial variation in tolerance to Zn deficiency, especially among bread wheats. The most Zn-efficient (tolerant) cultivars were those developed from crosses with local landraces. Anatolian bread wheat landraces are very tolerant to Zn deficiency.
Several field and greenhouse experiments with different cereal species have shown that rye and durum wheat have an exceptionally high and low tolerance to Zn deficiency, respectively. Tolerance of cereal species to Zn deficiency declined in the order rye > triticale > barley > bread wheat > oat > durum wheat. Tolerance to Zn deficiency also was studied in different Aegilops and wild and primitive wheat species. Certain Aegilops species were found to be exploited as an important genetic source for Zn-efficiency genes, particularly Ae. speltoides var. ligustica and Ae. triuncialis and some accessions of Ae. tauschii. A large variation in tolerance to Zn deficiency also was found among and within diploid, tetraploid, and hexaploid wheats. All wild, primitive and modern tetraploid wheats were extremely highly sensitive to Zn deficiency, whereas primitive and wild diploid wheats and most primitive hexaploid wheats had a higher tolerance to Zn deficiency. These results with wild species of wheat suggest that the AA and DD genomes possibly have genes responsible for expression of high Zn efficiency in wheat. The BB genome of tetraploid wheat also likely has suppressor genes for Zn efficiency. In good agreement with these suggestions, studies with synthetic wheats have demonstrated that the addition of the D genome from Ae. tauschii or the A genome from T. monococcum to tetraploid wheat markedly increased tolerance of the tetraploid wheat to Zn deficiency.
The physiological reasons for differential genotypic tolerances to Zn deficiency were extensively studied, but there are still questions to be answered. Increasing evidence suggests that an efficient utilization of Zn at the cellular level seems to be a major factor affecting expression of high tolerance to Zn deficiency. However, a better utilization of Zn in tolerant genotypes has to be associated with an enhanced Zn uptake rate by roots to maintain high growth rates at low tissue concentrations of Zn.
THRACE AGRICULTURAL RESEARCH INSTITUTE
P.O. Box 16, Edirne, Turkey.
Metin Babaoglu.
Saroz-95 was developed in 1995 at the Thrace Agricultural Research
Institute by combination breeding. The cross was 'Cor71-11460/3/Pkg/Lov13//JSW3'
and the pedigree is TE2682-1T-5T-1T-1T-0T. TE stands for Thrace-Edirne
and the T in the pedigree stands for the Thrace region where the
plant selection was made. The cultivar was developed and released
in 1995, but registered in 1999. Saroz-95 was named after the
bay, Saros, located in Thrace region. Some characteristics of
the cultivar are