ITEMS FROM THE CZECH REPUBLIC

RESEARCH INSTITUTE FOR CROP PRODUCTION, PRAGUE-RUZYNE

Drnovská 507, CZ-161 06 Praha 6, Ruzyne, Czech Republic.

Evaluation of wheat and triticale collections in the Czech gene bank.

Z. Stehno, L. Dotlacil, and M. Vlasák.

The department of the Czech gene bank is responsible for evaluating collections of winter and spring wheat, winter barley, and winter and spring triticale genetic resources. Collections increased during 1995, and numbers are presented in Table 1.

Table 1. A survey of cereal collections evaluated and

maintained in the Czech gene bank.

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Genetic Number of accessions

resources _______________________________

collection Received in 1995 Total

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Winter wheat 219 5,577

Spring wheat 88 3,747

Winter barley 20 1,555

Winter triticale 35 277

Spring triticale 46 67

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For evaluation of the genetic resources of cereals, a new version of the `Methodology of cereals germplasm study' was prepared, discussed, and accepted. The whole process of evaluation has been divided in the preliminary work and is the base evaluation.

Altogether, 560 accessions of winter wheat, 197 of spring wheat, and 36 of winter and 145 of spring triticales were evaluated in plots of four accessions each with 2.5 sq m of harvest area. Morphological characters and phenologic phases were recorded, and spike productivity and grain quality were analyzed in the evaluated accessions.

Cultivars included in the base evaluation were sown in an infection nursery to test their tolerance and resistance to the main fungus diseases. The experiment, with eight cultivars of T. spelta on 10 sq m plots in four replications, has continued, and cultivars suitable for locality conditions have been recommended.

A set of 124 wheat landraces of European origin was evaluated in detail, and valuable combinations of characters have been separated by cluster analysis.

Belonging to the set of the highest yielding cultivars of winter wheat, which outyielded the average of the domestic check cultivar Sparta (8.81 t/ha), were Admiral 8.98 t/ha and Brigadier (both from the United Kingdom) 8.90 t/ha. The French cultivar Barouder (8.25 t/ha) approached the yield of the check cultivar.

In the second experiment, the wheat cultivars Estica (8.90 t/ha) and Ritmo (8.80 t/ha) from the Netherlands outyielded the check cultivar Sida (8.61 t/ha).

The highest-yielding winter triticale cultivars, Ugo 9.22 t/ha and Prego (Poland) 8.84 t/ha, Purdy (the Netherlands) 8.98 t/ha, Trick (France) 8.97 t/ha, and Trimaron (Germany) were evaluated.

The spring wheat cultivars Thasos 8.36 t/ha, Devon (Germany) 7.72 t/ha, and Avans (Sweden) 8.27 t/ha outyielded the check cultivar Jara (6.92 t/ha).

Among Mexican spring triticale lines, `Peura-5-1' (8.31 t/ha), `Papion-4' (8.15 t/ha), and `Lamb-2' (8,09 t/ha) had yields greater than 8 t/ha.

The above-mentioned collections have been increased in addition to the newly registered cultivars.

Winter wheat cultivars registered in the Czech Republic in 1995.

`Alka' is a cultivar bred by the SELGEN Ltd. breeding station at Uhoetice, from the base cross `Hana/Mercia'. The cultivar is medium-early, with lower winterhardiness, medium resistance to lodging, and good resistance to grain sprouting. Spikes of Alka are white, pyramidal, lax, and semi-awned, with a very dense, waxy bloom in the period after heading. Kernels are large and elongated with a red hue. Baking quality is good (7), wet gluten content is higher, and sedimentation value and falling number are good. The cultivar has a medium level of resistance to powdery mildew, Septoria, stem rust, and the contemporary races of glume and leaf rusts.

`Boka', bred by MORSTAR Ltd. breeding station at Braniovice, is from an initial cross `Viginta/Selekta'. Boka is a medium-early cultivar of medium height, good winterhardiness, medium resistance to lodging, and low resistance to grain sprouting. The spikes are white, pyramidal, lax, and semi-awned. Kernels of medium size are elongated, with a red hue. Baking quality is good (7), wet gluten content and sedimentation value medium, and falling number lower under wet growing conditions. Resistance is good to the contemporary races of glume rust and medium to other diseases.

`Ina', a cultivar bred by PLANT SELEKT Ltd. as a selection from a `Hana/UH 7//Regina' cross, is a medium-early, medium-height cultivar with good winterhardiness and resistance to lodging. The resistance to grain sprouting in Ina is medium. Ina has white, cylindrical, semi-awned spikes with a medium density of spikelets. Kernels are of medium size and elongated and with a red hue. Baking quality usually reaches the 6th degree. Wet gluten content is lower; sedimentation value and falling number are intermediate. The cultivar has good resistance to contemporary races of glume rust and a medium level of resistance to the powdery mildew, Septoria, and leaf rust fungi. Ina has a lower level of resistance to stem rust.

`Samara' is a cultivar bred by SELGEN Praha, Ltd. Samara was selected from the cross `Regina/CWW WN 156'. Vegetative period is mid-late, growth height medium, and winterhardiness high. The cultivar has a medium level of resistance to lodging and grain sprouting. Spikes are white, cylindrical, semi-awned, and medium dense. Kernels are large, elongated, and with a red hue. Samara is not suitable for baking purposes (degree of baking quality is 3). Protein content is medium, sedimentation value lower, and gluten swelling low. The cultivar is resistant to contemporary races of glume rust and of medium-resistance to the powdery mildew, Septoria, leaf rust fungi. Samara has low resistance to stem rust.

In addition, two foreign wheats `Astella' (Slovakia) and `Estica' (the Netherlands) were registered in the Czech Republic in 1995.

Genes for resistance to leaf and stem rusts and powdery mildew in winter wheat cultivars registered in the Czech Republic in 1995.

P. Bartos and R. Hanusova.

An analysis based on Flor's gene-for-gene hypothesis was used to postulate genes for resistance to leaf and stem rust in the winter wheat cultivars registered in the Czech Republic in 1995. The following results were obtained: `Alka' (Mercia/Hana) Lr+, Sr+; `Astella' (Viginta/SO-80-2208) Lr3; `Boka' (Selekta/Viginta) Sr+; `Ina' (Hana/UH 7//Regina) Sr5?; and `Samara' (CWW-WN-156/Regina) Lr+.

The Pm2 and Pm6 genes for powdery mildew-resistance were determined to be in Samara. Cultivars Alka, Astella, Boka, and Ina had no specific resistance genes. The study on the suppression of the gene Pm8 by a specific gene-inhibitor in several lBL·lRS cultivars was continued. The gene-inhibitor in cultivars Agra, Sabina, and Florida were found to be identical. The same gene-inhibitor was found in the Czech cultivar Regina, without the lBL.lRS translocation.

Of the cultivars registered earlier, the following genes for resistance were determined using a set of yellow rust isolates (P. striiformis): Asta Yr1, Hana Yr2, Regina Yr1, Rexia Yr3a+4, Sida Yr9, Siria Yr2, Sparta Yr9, Vega Yr2, and Viginta Yr2 and Yr3a+4a. No specific resistance genes were identified in Bruta, Ilona, and Samanta.

Results of testing winter wheats for resistance to barley yellow dwarf virus.

J. Vacke, V. Sip, and M. Skorpik.

Response to an infection with BYDV was evaluated for 3 years in field trials with 30 Czech and Slovak winter wheat cultivars and advanced breeding lines. Experimental plants (both infected (I) and noninfected (i.e., control, C) were grown on 2-row plots, 1 meter long, with three replications. Infection with the PAV isolate of BYDV was performed in the autumn at the beginning of tillering stage by Rhopalosiphum padi aphids reared in the greenhouse. Symptoms of infection were evaluated at full-flower, using the scale developed by Schaller and Qualset (1980). After harvest, yield characters were determined and the susceptibility index (SI), according to Comeau and St-Pierre (1982) as modified by Sip et al. (1995), was calculated.

Table 2. Percent reductions (100-I/C.100) in yield characters of Czech and

Slovak winter wheat cultivars and breeding lines.

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Character Range Mean

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1000-kernel weight 10.3 (Sofia) - 21.8 (Blava) 16.0

Grain weight/ear 22.2 (Agra) - 60.0 (Sida) 41.1

Grain yield/ha 20.2 (Agra) - 70.2 (Sida) 41.3

Biomass 9.2 (Agra) - 43.9 (SG-S 2431-90) 32.0

Harvest index 1.9 (Torysa) - 39.2 (Branka) 14.9

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The average reductions from BYDV infection were high for grain yield per ear and per area (41 %), somewhat lower for biomass yield (32 %), and approximately 15 % for harvest index and 1,000-kernel weight (Table 2). The mean reduction in ear number per plant (1.7 %) was negligible. Symptom scores varied from 4.3 (Sofia) to 7.1 (Vlada), and SI varied from 1.22 (Sparta) to 4.25 (Sida).

The cultivars Sparta, SG-U 2105, Sofia, and Danubia (all with an SI < 2 and SS < 4; Table 2), and also, by comparative checking, Agra, Torysa, Samara, Samanta, SG-U 767, Vega, Zdar, Regina, Livia, and Asta, could be classified as moderately resistant to BYDV. A group of 13 cultivars was characterized by a moderately susceptible reaction. Among the tested cultivars, Sida, Vlada, and Branka with SIs > 4 (Sip et al. 1995) exhibited the most susceptible reactions to BYDV.

Table 2. 3-year average values of yield characters (I variant), symptom score (SS),

and susceptiblity index (SI) in the Czech and Slovak winter wheat cultivars with a

high level of resistance to BYDV (The cultivar Vlada is the susceptible check).

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Grain Grain Harvest Symptom Susceptibility

yield weight/ear index score index

Cultivar (t/ha) GWE HI SS SI

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Sparta 4.14 1.28 0.471 4.8 1.22

SG-U 2105 4.58 1.41 0.416 4.7 1.33

Sofia 4.00 1.25 0.423 4.3 1.33

Danubia 3.87 1.29 0.410 4.9 1.72

Vlada 2.52 0.72 0.374 7.1 4.06

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* Scale: 0 = fully resistant; 9 = fully susceptible

SI = 10-/3.75 GWE + 12 HI + 0.2(10-SS)/.0.77

With the aim of increasing BYDV resistance, spring wheat sources of resistance (mainly the cultivar Maringa and its NILs with Rht genes) were used in hybridization programs. The Maringa Rht1, Rht2, and Rht1+2 lines were crossed with the Czech cultivars possessing moderate resistance (Sparta) and other desirable characters, resulting in valuable winter wheat materials with improved BYDV resistance (symptom score approximately equal to 3).

Use of the GA-insensitive gene Rht1 in wheat breeding.

V. Sip, M. Skorpik, and J.Chrpova.

Hybridzation analyses and pedigree studies showed that all gibberellic acid (GA)-insensitive Czech and Slovak cultivars have the Rht1 gene, namely the winter wheat varieties Agra, Danubia, Branka, and Vlada (from the pedigree, also Iris and Ilona) and the spring wheat varieties Linda, Sandra, and Saxana. Exclusive exploitation of the Rht1 gene in Czech and Slovak wheat breeding could not be explained by the yield advantage of Rht1 over Rht2 (on the basis of trials with NILs for the Rht genes). However, yield differences from environmental means were less variable for Rht1 lines (s2 = 3.46 x 10-3; b = 0.99) than for Rht2 lines (s2 = 11.28 x 10-3; b = 1.06), which may indicate better adaptability of the Rht1 genotypes.

No evidence was obtained for making distinctions between the GA insensitivity of Siete Cerros (Rht1) and Saitama 27 or Produttore (`weak' Rht1S allele according to Worland and Petrovic 1988). After 10 days of treatment with 50 ppm GA3, the mean measurements of the first leaf sheath for carriers of Rht1S (`Saitama 27' and `Produttore)' of 32.8 +/- 1.19 mm were not significantly different from those of `Siete Cerros' (Rht1 at 33.2 +/-1.05 mm; Fig. 1).











Fig. 1. Similar GA insensitivity between Saitama 27 or Produttore (Rht1S) and Siete Cerros (Rht1). Insensitivity of near-isogenic-lines for Rht genes in Mironovskaya 808, in comparison with control sensitive rht line (10 days treatment with 50 ppm GA3).

Publications.

Comeau A and St-Pierre CA. 1982. Trials on the resistance to barley yellow dwarf virus (BYDV). Report no. 4. Research Station, Agriculture Canada, Sainte-Foy, Quebec, Canada.

Schaller CW and Qualset CO. 1980. Breeding for resistance to the barley yellow dwarf virus. In: Proc 3rd International Wheat Conference, Madrid, Spain. University of Nebraska Agricultural Experiment. Station publication MP41. Pp. 528-541.

Sip V, Skorpik M, Chrpova J, and Dotlacil L. 1995. GA insensitive dwarfing genes of wheat in the conditions of Czech Republic. Proc XIV Eucarpia Congress on Adaptation in Plant Breeding, Jyvaskyla, Finland. Pp. 40-41.

Sip V, Vacke J, and Skorpik M. 1995. Response of Czech and Slovak winter wheat varieties to the infection with barley yellow dwarf virus. Genet a Slecht (Genetics and Plant Breeding). Praha 31:253-266.

Worland AJ and Petrovic S. 1988. The gibberellic acid insensitive dwarfing gene from the wheat variety Saitama 27. Euphytica 38:55-63.