ITEMS FROM CROATIA

BC INSTITUTE FOR BREEDING AND PRODUCTION OF FIELD CROPS

Department of Cereal Crops-Botinec, Marulicev trg 5.I, 10000 Zagreb, Croatia.

Yield and quality of the recently released winter wheat cultivars from the Bc Institute-Zagreb.

P. Javor, S. Tomasovic, and B. Sesar.

The development of semidwarf and moderately high winter wheat cultivars with increased productivity, wide adaptability, and improved grain and flour quality is main objective in breeding winter wheat at the Bc Institute-Zagreb, Croatia. Breeding for stability of yield and adaptability is through four programs. Each program includes incorporation of genetical resistance to one of the economically important fungal diseases in Croatia (stem rust, powdery mildew, glume blotch, and FHB).

Table 1 lists the registered cultivars derived from each of these programs. Some results from the 3-year variety trials of the Republic Commission for Variety Registration are given in Table 2. Remarkable yield progress is obvious when comparing standard varieties to some new cultivars. Most of the cultivars have a satisfactory resistance to the main diseases. Test and 1,000-kernel weights in 1995 were lower than normal (Table 3). Flour quality differs from C₁ to B₁, after Hankoczy. Cultivar Posavina has the highest bread quality, slightly better than the standard variety Zitarka.

Table 1. Winter wheat cultivars developed by the Bc Institute-Zagreb from various breeding programs for resistance to important wheat diseases and registered in the Republic of Croatia (Cultivars in bold are widely spread over 5 % of harvested area).

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¹ Authors for cultivars 1 and 2 are Potocanac J, and Engleman M; and for cultivar 3 is Engelman M, Mlinar R, and Matijasevic M.
² Authors for cultivars 1-15 are Potocanac J and Javor P; and for 16-28 are Javor et al.
³ Authors for cultivars 1-9 are Mlinar et al.
⁴ Authors for cultivars 1-10 are Tomasovic et al.
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Insert Table 2.

Insert Table 3.

Improvement of resistance to Fusarium head blight (Fusarium graminearum Schw.) in common wheat at the Bc Institute-Zagreb

S. Tomasovic and P. Javor.

Introduction. Systematic work on discovering sources of resistance to F. graminearum, the most frequent pathogen of FHB in the wheat-growing areas in Croatia, was initiated at the Zagreb Bc Institute for Breeding and Production of Field Crops in 1976. All sources from the collection were tested for FHB resistance under both artificial and natural infection conditions. Seven sources with higher levels of resistance were identified and selected for breeding wheat for resistance to F. graminearum.

Methods. Among the seven selected sources, a partial diallel cross was made in order to accumulate alleles resistant to F. graminearum. The F₁ progeny from single and double crosses of the resistant cultivars were tested at anthesis by artificial infection with the selected F. graminearum isolates. In parallel, a part of the F₁, the parental lines, and Zlatna Dolina (check) were tested under natural infection. These plots were isolated 200 m from the artificially-infected plots. Materials were tested in varietal trials, with five replicates. Disease resistance was evaluated by an international scale 0-5 (Luzzardi et al 1974; Bekele 1984; Liu 1984). Disease severity was rated twice at a 2-week interval. Higher marks for disease severity were noted on the same material. Thirteen F₁ combinations together with the single crosses and 34 F₁ combinations of the double crosses were tested. The best results are given in Tables 4 and 5.

Results and discussion - Trial 1. The results of trial 1 indicate that the selected sources of resistance significantly differ in their resistance to F. graminearum under conditions of artificial and natural infection. The cultivar Encruzilhada had the highest resistance (0.58) of the artificially infected lines (Table 4). High levels of resistance also were recorded for Bizel, Poncheau, and Mironovskaya 808. Bizel had the highest level of resistance (0.18) under natural infection, followed by Poncheau, Encruzilhada, and Mironovskaya 808.

In the F₁ of the single crosses, the best resistance was found in the cross `Mironovskaya-808 x Poncheau' (0. 54). A high level of resistance also was found in the `Bizel x Mironovskaya-808' cross (0.61). Resistance of the F₁ to F. graminearum is better than the resistance of each parent under conditions of artificial infection. In the F₁ of double crosses, the highest levels of resistance were in the crosses `Bizel/Mironovskaya-808//Mironovskaya-808/Poncheau' (1.70). A high level of resistance also was found in the cross `Bizel/Poncheau//Mironovskaya-808/Balaya-cerkov' (2.20).

Based on the resistance in the F₁ generation of the single and double crosses artificially infected with F. graminearum, the highest levels of resistance were in the single crosses `Bizel/Mironovskaya-808' and `Mironovskaya-808/Poncheau'. By combining these three parents in double crosses, we were able to obtain considerably lower resistance levels than in any of the single-cross combinations.

Trial 2. Under the artificial-infection conditions of trial 2, the cultivar Encruzilhada again was resistant (0.83) to F. graminearum, and Roazon also was the most susceptible (3.87) (Table 5). When naturally infected, the best resistance was in Bizel (0.33) and Encruzilhada (0.47). Roazon again had the lowest resistance (2.57).

In the F₁ of the artificially-inoculated single crosses, the highest levels of resistance were in the crosses `Toropi/Encruzilhada' (0.50) and `Roazon/Encruzilhada' (0.52). This resistance was better than that of the best parent of the crosses. In the F₁ of the artificially-inoculated double crosses, the highest resistance was in the cross `Toropi/Encruzilhada//Roazon/Encruzilhada' (1.07). The cross `Roazon/Mironovskaya-808//Balaya-Cerkov/Poncheau' also had a high level of resistance (1.50).

Table 4. Sources of resistance to Fusarium graminearum Schw. from Trial 1 under conditions of artificial and natural infection, and compared with single and double crosses of the F₁ generation and the check cultivar Zlatna Dolina.

Source of resistance (Parents) and F1 crosses	Disease Severity (0-5*)		Increase of disease severity in artificial infection in relation to natural infection (%)
	Artificially infected	Naturally infected
Parental lines
1. Toropi (TRP)	2.98	1.88	36.9
2. Roazon (RZN)	4.12	2.38	42.2
3. Encruzilhada (ECR)	0.58	0.32	44.8
4. Bizel (BZL)	1.24	0.18	85.5
5. Mironovskaya 808 (M-808)	1.84	0.42	77.2
6. Balaya-Cerkov (BLC)	3.18	0.86	72.9
7. Poncheau (PNC)	1.30	0.28	78.5
F1 (single crosses)
1. (M-808 x PNC)	0.54	0.26	51.9
2. (BZL x M-808)	0.61	0.34	44.3
3. (TRP x ECR)	1.00	0.60	40.0
4. (BZL x BLC)	1.00	0.00	100.0
5. (BZL x PNC)	1.20	0.25	79.2
F1 (double crosses)
1. BZL/M-808//M-808/PNC	1.70	0.10	94.1
2. BZL/PNC//M-808/BLC	2.20	1.00	54.5
3. RZN/BZL//M-808/PNC	2.60	0.40	84.6
4. RZN/ECR//BZL/PNC	2.60	1.60	38.5
5. RZN/M-808//TRP/BZL	2.60	2.00	23.1
Zlatna Dolina (check)	3.82	1.95	48.9
LSD 5 %	1.34	0.42
LSD 1 %	1.76	1.12

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* Scale: 0 = no infection, 0-1 = resistant, 2 = moderate resistance, 3 = moderate susceptibility, 4 = susceptible, 5 = more than 75 % diseased spikes

Under conditions of artificial infection, the highest level of resistance to FHB was in the F₁ of the single crosses `Toropi/Encruzilhada' and `Roazon/Encruzilhada'. The level of resistance in these crosses was the highest in all the trials. Combining these three parents in double crosses as in trial 1, a level of resistance to F. graminearum considerably lower than the resistance of each combination of the single crosses was obtained.

The LSD was highly significant in both trials. Improvement of resistance in wheat to F. graminearum were made in the progeny of F₁ generation of the single crosses, compared to using the better parent source of resistance, which indicates an additive gene effect. In following generations, resistance to FHB was on the same level as that in the F₁.

Table 5. Wheat sources of resistance to Fusarium graminearum Schw. from Trial 2 under conditions of artificial and natural infection compared with single and double crosses of the F₁ generation and the check cultivar ZlatnaDolina.

Source of resistance (Parents) and F1 crosses	Disease Severity (0-5*)		Increase of disease severity in artificial infection in relation to natural infection (%)
	Artificially infected	Naturally infected
Parental lines
1. Toropi (TRP)	2.73	2.00	26.7
2. Roazon (RZN)	3.87	2.57	33.6
3. Encruzilhada (ECR)	0.83	0.47	43.4
4. Bizel (BZL)	1.10	0.33	70.0
5. Mironovskaya 808 (M-808)	1.07	0.53	50.5
6. Balaya-Cerkov (BLC)	2.23	0.80	64.1
7. Poncheau (PNC)	1.23	0.53	56.9
F1 (single crosses)
1. TRP/ECR	0.50	0.33	34.0
2. RZN/ECR	0.52	0.33	36.5
3. BLC/PNC	0.83	0.17	79.5
4. BZL/PNC	0.87	0.61	29.9
5. BZL/BLC	1.06	0.28	73.6
F1 (double crosses)
1. TRP/ECR//RZN/ECR	1.07	0.00	100.0
2. RZN/M-808//BLC/PNC	1.50	1.33	11.3
3. RZN/BZL//BZL/PNC	1.83	1.67	8.7
4. RZN/PNC//BZL/PNC	2.00	1.33	33.5
5. BZL/PNC//TRP/ECR	2.00	0.83	58.5
Zlatna Dolina (check)	3.57	1.76	50.7
LSD 5 %	1.94	1.03
LSD 1 %	2.56	1.36

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* Scale: 0 = no infection, 0-1 = resistant, 2 = moderate resistance, 3 = moderate susceptibility, 4 = susceptible, 5 = more than 75 % diseased spikes.

Conclusions. Based on the investigations of wheat resistance to F. graminearum conducted at the Bc Institute for Breeding and Production of Field Crops, Zagreb, the following conclusions can be made:

1. From 1976, tests have been made on a large number of materials of both domestic and foreign origin and under both artificial and natural infection conditions. Seven sources of resistance were distinguished, based on their resistance level and good agronomic properties.
2. The selected sources of resistance differed greatly in their level of resistance. Infection severity in the best source, Encruzilhada, was 0.58 and in the most susceptible, Roazon, 4.12 when artificially infected. A comparatively high level of resistance similar to that in Encruzilhada was recorded in Bizel, Poncheau, and Mironovskaya-808.
3. Resistance in the F₁ of the best single crosses was considerably higher than that of the best parent.
4. Progeny of some single crosses had higher resistance levels than the progeny from double crosses from the same parents.
5. The results indicate additive inheritance of resistance to F. graminearum.
   
   

References.

Bekele GT. 1984. Head scab screening methods used at CIMMYT. Proceedings of an International Symposium. CIMMYT, Mexico. pp. 169-173.

Liu ZZ. 1984. Recent advances in research on wheat scab in China. Proceedings of an International Symposium. CIMMYT, Mexico. pp. 174-181.

Luzzardi GC, Plerobom CR, Osorio EA, Moreira JCS, Wetzel MMVS, and Dias JCD. 1974. Melhoramento de trigo para resistencia a Gibberella. Anais de I. Reuniao Latinoamericana de trigo. Porto Alegre, R.S. pp. 117-121.

ITEMS FROM THE CZECH REPUBLIC

RESEARCH INSTITUTE OF CROP PRODUCTION - RICP

161 06 Prague 6 - Ruzyne, Czech Republic.

Genetic resources of wheat and triticale - some conclusions of evaluation in 1996.

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

The Department of the Gene Bank is responsible for the evaluation of cereal genetic resources of collections of winter and spring wheat and winter and spring triticale. Collections were increased during 1996 and attained the following numbers (Table 1).

Table 1. Survey of cereal genetic resources (GR) collected and gradually evaluated in the gene bank, RICP, Prague.

GR collection	Number of accessions
	Received in 1996	Total
Winter wheat	104	5,680
Spring wheat	127	3,873
Winter triticale	37	314
Spring triticale	46	67
Total	314	9,934

Morphological characteristics and phenological phases were recorded, analyses of spike productivity and grain quality made, and tolerance or resistance to the main fungus diseases were evaluated during the vegetative period.

Hungarian cultivars headed later, but reached full ripeness earlier than other genetic resources among winter wheat accessions. The cultivar Admiral (U.K.) had a high 1,000-kernel weight of 51.2 g. The U.K. cultivars Brigadier and Admiral were highly tolerant to powdery mildew. The grain yield of Brigadier (U.K.) at 10.51 T/ha was greater than the check cultivar Sparta (Czech Republic) at 9.47 T/ha.

Evaluation of a collection of T. spelta genetic resources was aimed at evaluating resistance to lodging, grain quality, and yield potential. The level of yield was 47-67 % that of common wheat productivity. The old German cultivars Wagenhouser Kolbendinkel and Fugers Babenhauser Zucht were the most productive.

The spring wheats Adonis (the Netherlands) and Quatro (Germany) were highly resistant to stem rust. Attis, Devon, and F40 (all from Germany) were resistant to stripe rust. The yield level of the check cultivar Munk (Germany) 8.97 T/ha was surpassed only by Devon at 9.02 T/ha.

Polish winter triticales were the most productive triticales tested in the potato-growing areas. A yield level of 9 T/ha was surpasses by only Tewo (9.98 T/ha), Purdy (9.48 T/ha), Alamo (9.23 T/ha), and Moreno (9.21 T/ha). Most of cultivars were highly resistant to lodging. Advanced lines of spring triticale from Mexico had good lodging resistance and nearly all of them were more productive than the Czech spring wheat Sandra.

On the basis of published information, evaluation results, articles, and the catalogue of cereals, the gene bank was asked for and provided the following number of seed samples to breeders and research workers (Table 2).

Table 2. Number of seed samples of cereals provided to users in 1996.

Vernalization requirements of some cultivars of winter wheat.

K. Pankova and J. Kosner.

Winter wheat cultivars grown in the Czech republic were vernalized for 3-8 weeks at temperatures from 1-3 C. Vernalized seedlings were planted in an experimental plot on 20 April, when low temperatures are not expected to occur that could cause vernalization in situ. The length of the period from planting to heading was observed. The vernalization requirement was defined as the number of weeks of vernalization sufficient to produce full vernalization. Under this length of vernalization, the period to heading did not differ significantly compared to conditions of a full 8-week vernalization. The basic vernalization requirement was determined as the number of weeks of vernalization after the plants headed, even if large delay occurred in some cases (Table 3).

Table 3. Vernalization requirements of some winter wheat cultivars.

Variety	Earliness days to heading at 8-week vernalization	Vernalization requirement (weeks)
		Full vernalization	Basic vernalization
Hana	56.72	8	4
Astella	57.40	8	4
Samanta	57.45	7	4
Mona	57.88	7	3
Boka	58.42	8	4
Ina	58.83	8	4
Alka	61.46	7	4
Sida	64.00	7	4
Asta	66.61	7	3
Estica	68.03	8	4
Siria	69.81	6	5
Samara	70.65	7	4
Vega	71.00	7	3

Response of Czech and Slovak winter wheat cultivars to the infection of ears with Fusarium culmorum.

E. Stuchlakova and V. Sip.

Response to the infection of ears with F. culmorum was studied in field trials with 18 Czech and Slovak winter wheat varieties for 3 years (Stuchlakova and Sip 1996). Ears were inoculated with isolate 7710 at full flowering of middle spikelets. Visual evaluation of symptoms was made on a scale of 0-4 (0 = no symptoms), estimating the percentage of bleached ears and intensity of symptoms in groups of `2 x 10' ears. Tolerance to fungal infection was evaluated on the basis of yield performance in the infected variant compared to the uninfected variant. Analysis of variance showed significant differences between cultivars and years for all the examined traits. Relatively lower (insignificant in 4 of 10 cases) were the interaction mean squares, which implies that the relative resistance or tolerance of cultivars varies to some extent from year to year, but basic changes do not occur. On average, the pathogen-caused reduction in the 1,000-kernel weight, grain number per ear, and grain weight per ear was 46.7 %, 25.9 %, and 58 %, respectively.

Symptom scoring was not significantly correlated with the reduction of 1,000-kernel weight and grain weight per ear but was significantly correlated grain number per ear only in 1992 when the level of disease severity was high. Highly-resistant cultivars were not found among the tested wheats. However, Senta, Sparta, Branka, and Sofia with scores ranging from 1.3 to 1.6 could be classified as moderately resistant to F. culmorum. These cultivars differed significantly from the moderately- and highly-susceptible cultivars by having a relatively lower reduction of 1,000-kernel weight and grain weight per ear after the infection. The cultivar Zdar was included among the moderately-resistant cultivars with low ear density. Higher tolerance evidently was connected with slower disease development. The most susceptible reaction to the infection (> 3) was exhibited by the very short varieties Iris and Livia and also in Torysa, Danubia, and Vega on the basis of 2-year examination.

Publications.

Stuchlakova E and Sip V. 1996. Resistance of Czech and Slovak winter wheat varieties to Fusarium head blight. Genet a Slecht Praha (Genetics and Plant Breeding) 32:79-94.

Perkowski J, Lasocka I, Stuchlakovay E, Sip V, Golinski P, and Bartos P. 1996. Response of Czech and Slovak wheat varieties to Fusarium culmorum leading to trichothecenes content in grain. Genet a Slecht Praha (Genetics and Plant Breeding) 32:73-77.

Genes for resistance to leaf and stem rusts and powdery mildew in winter wheat cultivars registered in the Czech Republic in 1996.

P. Bartos, R. Hanusova, and V. Blazkova.

An analysis based on Flor's gene-for-gene hypothesis was used to postulate genes for resistance to leaf rust, stem rust, and powdery mildew in the winter wheat cultivars registered in the Czech Republic in 1996 with the following results: Athlet (Lochow Petkus) - Lr26, Sr31, Pm2+, and Pm8; Brea (BR 918/ Hana) - Lr3 and Sr+; Bruneta (Viginta //Viginta / BR 918) - Lr3 and Sr+; and Ritmo (Cebeco Zaden B.V.) - Lr+, Pm2+, and Pm6.

Wheat leaf rust pathotypes determined in 1996. Analysis of the 1996 wheat leaf rust population from the Czech Republic showed that race UN3-61SaBa was, as in previous years, the most prevalent. Isolates of this race could be differentiated into three groups according to their reactions on Lr15 and Lr17. Most of the races were virulent on Lr15 and Lr17, followed by isolates avirulent on those genes. Some isolates were avirulent on Lr15 and virulent on Lr17. Among the other races, UN3-61, UN10-14, UN13-77, UN13-77SaBa, UN1-1, UN2-2, and UN3-12SaBa were identified. Of the tested NILs with Lr1, Lr2a, Lr2b, Lr2c, Lr3, Lr9, Lr11, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26, and Lr28; only lines with Lr9, Lr19, Lr24, and Lr28 were resistant to all 89 isolates. A low frequency of virulence was found to Lr1 and Lr2a.

Common bunt. Thirty-nine cultivars described as resistant or partially resistant by various authors were tested for reaction to a mixture of T. caries (race T-1) and T. laevis (race L-5). No infection was found in cultivars Amigo, Crest, Franklin, Stava, and Tjelvar. Cardon, Wasatch, Hildebrands Weissweizen B, Shekhurdinovka, Nebred, and Dobrovicka presivka were of low infection (0.9-9.1 %). Separate inoculations with T. caries and T. laevis were made in other trials. None of the cultivars registered at present in the Czech Republic or the advanced lines in the State Varietal Trial are resistant to T. laevis (race L-5). Only advanced line HE-3625 was resistant to T. caries (race T-1). None of the foreign cultivars tested in the State Varietal Trial are resistant to T. laevis (race L-5); and only cultivars Bussard and Euris has less than a 5 % of infection with T. caries (race T-1).

The following were resistant to both inocula: lines/cultivars with resistance genes Bt3, Bt4, Bt5, Bt6, Bt8, Bt9, Bt10, Bt11, Bt12, and Bt13, and the sources of resistance PI 560795 (SEL.BCO; T. aestivum collected in Hakkari, Turkey, by Eser and Gecit, Ankara University; white seeded, awns and glumes brown, nonpubescent.), PI 560841 (SEL.WCO; T. aestivum collected in Hakkari, Turkey, by Eser and Gecit, Ankara University; white seeded, awns tan, glumes brown, glabrous), and PI 560841 (SEL.BCL; T. aestivum collected in Hakkari, Turkey, by Eser and Gecit, Ankara University; white seeded, awns tan, glumes brown, glabrous, possibly a spring-sown wheat).

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