Research Highlights of the CIMMYT Wheat Program 1999-2000

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in CAC. In Turkey, the advantage over Kinaci 97 and Sultan 95, the latest variety releases for irrigated areas on the Central Plateau, is 6%. In Iran, the best check was outyielded by 2% and the local check by 5%. This supports data from the WWEERYT that lines developed by the IWWIP are well adapted across large areas in CWANA. These lines combine yield potential with resistance to yellow rust and stable yields across the region. Kinaci 97 was released in Turkey, Afghanistan, and Uzbekistan. At present only in Turkey and parts of Iran is supplementary irrigation a common procedure; in most other areas, full irrigation systems are applied. The latter favor late maturing cultivars. Due to the catastrophic droughts that have struck CWANA countries, growing public concern over water shortages, and increasingly intensive crop rotations, breeding early maturing cultivars adapted to supplementary irrigation regimes will become a high priority in most CWANA countries. Results from the EYT-IR suggest that lines adapted to supplementary irrigation systems are already available. Progress in raising winter and facultative wheat yields Bezostaya 1 was widely grown in CEE until 15 years ago and still is in several countries of CWANA. This was due particularly to its quality characteristics and grain plumpness. Bezostaya also has an excellent winter survival rate, as results of the Facultative and Winter Wheat Observation Nursery show. Distributed worldwide, this nursery includes elite wheat cultivars from Europe, North America, CWANA, and the IWWIP, but no entries that are cold tolerant in all environments. This is understandable, since the development, maintenance, and breakdown of frost tolerance are controlled by both genetic and environmental factors. A large area is still sown to Bezostaya, perhaps partly due to its ability to cope with the wide range of stresses in cold environments; in contrast, other genotypes are more specifically adapted to cold stresses occurring in either humid or dry areas. This ability is of particular importance in areas where agronomic practices and seedbed preparation are poor, as is the case in large areas of WANA. Data from the 1st and 2nd WWEERYT and the 3rd and 4th Elite Yield Trial for irrigated areas were used to estimate progress in increasing yields of new cultivars relative to Bezostaya. In total, data from 24 trials in CEE and 54 trials in CWANA during 98-99 and 99-00 were considered (Tables 3 and 4). The local check yielded below Bezostaya in 12 trials in CWANA and 1 trial in CEE. In none of the trials did Bezostaya have the highest yield. The highest yielding entry outyielded Bezostaya by at least 20% in 46 of 54 trials in CWANA and in 20 of 24 trials in CEE. In 26 trials in CWANA and 9 trials in CEE, the best check outyielded Bezostaya by more than 40%. Table 3. Fifty-four trials in CWANA and 24 trials in CEE grouped on yield advantage (%) of Local Check and highest yielding entry compared to Bezostaya. Data from 1st and 2nd WWEERYT and 3rd and 4th Elite Yield Trial (irrigated), 1998-99 and 1999-00. Frequency of trials Yield range Central/West Asia Central Eastern Europe (% Bezostaya) Local check Best entry Trial mean Local check Best entry Trial mean < 100 % 12 0 10 1 0 4 100 - 110 % 11 3 10 3 1 8 111 - 120 % 11 5 7 4 3 7 121 - 130 % 8 10 8 7 5 3 131 - 140 % 3 10 10 4 6 0 > 140 % 9 26 9 5 9 2 Total no. of trials 54 54 54 24 24 24 30
Progress is also obvious from the number of trials in which the mean yield of all entries is higher than the yield of Bezostaya (44 of 54 trials in CWANA and 20 of 24 trials in CEE). The average yield advantage of the highest yielding entry and the local check (using data from each location) was 46% and 27% in the 1st WWEERYT, 46% and 20% in the 2nd WWEERYT, 86% and 46% in the 3rd EYT, and 46% and 28% in the 4th EYT. Similar data are found when the average yield across locations is used as basis (Table 4). Again, progress of the highest yielding cultivars over Bezostaya varies from 20% to 43% in CWANA and 23 to 30% in CEE. Using single-location and acrosslocation data, it can be concluded that the yield of recently developed cultivars is at least 25% above that of Bezostaya. Root Rot Screening As noted above, the disease spectra are very dissimilar in CEE and CWANA, mainly due to different rainfall patterns. Among the major diseases in the dryland areas of the West Asia/ North Africa (WANA) region, root rots are also becoming increasingly important in areas with supplementary irrigation. In supplementary irrigation systems wheat is often not irrigated at the optimum time and can at times suffer from drought. Under such conditions, losses from dryland root rots in irrigated plots can be as high as 50%. Disease occurrence and frequency vary regionally, depending on climatic conditions and agronomic practices. The most commonly reported root rot pathogens are Cochliobolus sativus, Fusarium culmorum, Fusarium graminearum (Group 1), Fusarium avenaceum, and Rhizoctonia cerealis. Root rots most often affect seedling stand, reduce yield, and lower grain quality. Typical symptoms include discoloration and necrosis or rotting of roots, subcrown internodes, crown, and/or the stem. Severe root rots cause symptoms such as stunting, late death tillers, and premature ripening; bleaching of spikes commonly known as “white heads” or “dead heads” may occur. Root rots can be caused by one or a combination of pathogens. The use of resistant/tolerant cultivars is usually the most economic, sustainable, and environmentally sound control method. However, screening wheat for resistance to the root rot complex has been hindered by inadequate and inconsistent inoculation methods, and a lack of accurate and suitable disease evaluation techniques. Several studies were conducted in WANA to identify wheat germplasm resistant to this complex disease. In Turkey, however, very few studies have been conducted on root rots, and practically no screening of winter wheat germplasm. Hence, a major effort to address root rots was undertaken in the IWWIP in the 1999-00 crop season. One thousand six hundred wheat genotypes, including most released cultivars and advanced lines, were artificially inoculated with the major root rot pathogens (Cochliobolus sativus, Fusarium culmorum, Fusarium graminearum (Group 1), and Alternaria). Root Rot Screening Nurseries were planted in Cumra Station, 40 km from Konya City, Turkey, where root rot is frequently observed. Each genotype was planted in two adjacent plots (2 Table 4. Mean yield and yield advantage (%) of best entry over Bezostaya across all locations of 1st and 2nd WWEERYT (18 trials) and 3rd and 4th EYT-irrigated. Central/West Asia Central Eastern Europe Yield (kg/ha) Yield (%) Yield (kg/ha) Yield (%) Nursery Best entry Bezostaya Bezostaya Best entry Bezostaya Bezostaya 1st WWEERYT (21 trials) 6534 5456 120 6067 4652 130 2nd WWEERYT (18 trials) 5995 4725 127 6425 5213 123 3rd EYT-irrigated (19 trials) 5145 3595 143 4th EYT-irrigated (23 trials) 4955 3986 124 31
Page 2 and 3: Research Highlights of the CIMMYT W
Page 4 and 5: Table of Contents New Conservation
Page 6 and 7: Foreword We are pleased to initiate
Page 8 and 9: Hobbs on the zero-till planters fro
Page 10 and 11: Burning is practiced due to a lack
Page 12 and 13: (0.64 million ha), and Bolivia (0.2
Page 14 and 15: New Bread Wheats for High Rainfall
Page 16 and 17: CIMMYT scientists have published on
Page 18 and 19: Taken together these data indicate
Page 20 and 21: Evaluating Advanced Materials Targe
Page 22 and 23: this may simply reflect a lack of v
Page 24 and 25: eleased in more than 30 countries u
Page 26 and 27: Parallel enhancement of yield compo
Page 28 and 29: Taken together, these factors sugge
Page 30 and 31: of improved seed and new technologi
Page 32 and 33: The high cost of hybrid seed is one
Page 34 and 35: Only a few cultivars performed well
Page 38 and 39: ows, 2 m long). One plot was inocul
Page 40 and 41: Table 2. Wheat production statistic
Page 42 and 43: Based on farmers’ preferences, 12
Page 44 and 45: Global Monitoring of Wheat Rusts, a
Page 46 and 47: Monitoring nurseries The nurseries
Page 48 and 49: controlled by several QTLs with sma
Page 50 and 51: environments with strong disease pr
Page 52 and 53: eselections, studies at CIMMYT have
Page 54 and 55: References Johnson, R. 1978. Practi
Page 56 and 57: spike. Interaction between Lr19 and
Page 58 and 59: variation in the trait. Both grain
Page 60 and 61: the variation in yield (Figure 2).
Page 62 and 63: References Amani, I., R.A. Fischer,
Page 64 and 65: in ECSA rely heavily on CIMMYT whea
Page 66 and 67: the pivotal role of Kulumsa in the
Page 68 and 69: Regional wheat quality classificati
Page 70 and 71: Table 5. Regional screening nurseri
Page 72 and 73: In 1992-93 the CIMMYT office in Tur
Page 74 and 75: In addition to shuttle breeding sev
Page 76 and 77: the CIMMYT wheat breeding program.
Page 78 and 79: Five participants thought the level
Page 80 and 81: 35. Skovmand, B.; López C., C.; S
Page 82 and 83: 94. Tanner, D.G. 1999. Principles a
Page 84 and 85: 182. Díaz de León, J.L.; Escoppin
Page 86 and 87:
258. Mujeeb-Kazi, A.; Delgado, R.;
Page 88:
CIMMYT-Derived Bread Wheat, Durum W
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Research Highlights of the CIMMYT Wheat Program 1999-2000

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