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40 133 151 Li XP, Jiang CZ and Liu HL. 1995: Effect of the Rht1, Rht2 and Rht3 genes on spring wheat agronomic characteristics. Journal of

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Tartamkísérletben, Hajdúságban (Kelet-Magyarország), csernozjom talajon vizsgáltuk eltérő évjáratok (2007. év = száraz, 2008. év = kedvező vízellátottságú) és egyes agrotechnikai tényezők (vetésváltás, trágyázás, öntözés) kölcsönhatásait adott őszi búza fajta (Mv Pálma) agronómiai tulajdonságaira és termésére. A levél- (lisztharmat-, DTR-, levélrozsda-fertőzöttség) és kalászbetegségek (kalászfuzárium-fertőzöttség) mértékét döntően a trágyaadagok határozták meg, melyet az évjárat, a vetésváltás és öntözés kisebb-nagyobb mértékben módosított. A búza állományok megdőlését a kedvező vízellátottságú évjárat (2008. év) és a nagyobb trágyaadagok (N150–200+PK) jelentősen növelték. Aszályos évjáratban az őszi búza maximális termése bikultúrában 5590 kg/ha, trikultúrában 7279 kg/ha (nem öntözött), ill. 7835 kg/ha és 8492 kg/ha (öntözött) volt. A kedvező vízellátottságú évjáratban a búza termésmaximuma bikultúrában 7065 kg/ha, trikultúrában 8112 kg/ha (nem öntözött), ill. 6882 kg/ha és 7874 kg/ha (öntözött) volt. Aszályos évjáratban az öntözés maximális terméstöbblete 2630 kg/ha (bikultúra) és 1579 kg/ha (trikultúra) volt. Az öntözés termésnövelő hatása csak megfelelő tápanyagellátás mellett érvényesült (a víz- és tápanyagellátás interaktív hatása). A trágyázás hatására aszályos évjáratban 2853–3698 kg/ha (nem öntözött) és 3164–5505 kg/ha (öntözött) terméstöbbletet kaptunk. Kedvező vízellátású évjáratban a trágyázás termésnövelő hatását alapvetően meghatározta a vetésváltás (bikultúrában 3990–4050 kg/ha, trikultúrában 524–884 kg/ha terméstöbblet). Az évjárat és vetésváltás befolyásolta az optimális NPK adagot. Száraz évjáratban bikultúrában az N150–200+PK, trikultúrában az N100–150+PK, kedvező vízellátottságú évjáratban pedig az N150+PK (bikultúra) és az N50+PK (trikultúra) trágyakezelés bizonyult optimálisnak.

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Rice ( Oryza sativa L.) is one of the most important crops in the world, especially Asian countries. Genetics of important traits in rice for yield improvement have always been a major breeding objective. Agronomic traits are inherited quantitatively, so quantitative trait loci (QTL) mapping for the potential use of molecular markers would be very helpful to plant breeders in developing improved rice varieties. In this investigation, a SSR linkage map of 1440.7cM of rice was constructed using 105 polymorphic simple sequence repeat (SSR) markers. The mapping population of 236 F 2:3 families derived from the cross of two rice varieties (Gharib × Sepidroud) was used for QTL mapping of agronomic traits. As many as 38 QTLs were detected to be associated with agronomic characteristics; some of them are being reported for the first time. The identified QTLs on specific chromosome regions explaining high phenotypic variance could be considered to use in marker-assisted selection (MAS) programs.

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The study reports the effects of four sowing densities (40 × 10, 40 × 20, 60 × 10 and 60 × 20 cm) on the agronomic characteristics of Isatis tinctoria and I. constricta under the rainfed conditions of South Eastern Anatolia. Wide row spacings of 60 × 10 or 60 × 20 cm were effective in obtaining maximum number of leaves per plant, leaf length, leaf width, petiole length, stem diameter, fruit length, 1000 fruit weight and 1000-seed weight. However, narrow row spacing (40 × 10 or 40 × 20 cm) led to maximum values of fresh and dry leaf yield 10 m −2 , plant height, fruit yield and fruit length, minimum hull content, and the highest indican percentage and indican yield m −2 . This information will be helpful for the economical cultivation of these plants under the rainfed conditions of South Eastern Anatolia.

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This study was made in order to determine the correlations between seed yield and some yield components, and the direct and indirect effects of these characters on seed yield in sunflower. Four experimental synthetic varieties (Syn 1s), their parental mixtures (Syn Os) and two standard varieties (open pollinated: Vniimk 8931, and commercial hybrid: Sunbred-281) were evaluated in replicated field trials under Turkish conditions in 1995, 1996 and 1997. Agronomic characteristics such as plant height, head diameter, number of seeds per head, 1000-seed weight and seed yield were observed for correlations and path coefficient analysis.According to the results, seed yield gave significant positive correlations with plant height, head diameter, number of seeds per head and 1000-seed weight. The highest positive correlation was observed between seed yield and number of seeds per head (r=0.890**). Path analysis indicated that the number of seeds per head gave the greatest direct effect (+0.7269) on seed yield, followed by 1000-seed weight (+0.3215) and head diameter (+0.1689). The percentage of direct effects on seed yield was 80.8%, 50.6% and 24.0% for number of seeds per head, 1000-seed weight and head diameter, respectively.

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Abiotic stresses like salinity and abnormally cold environments cause significant yield losses in many crops including wheat. Therefore, concerted efforts are being made by breeders to develop new varieties with salt and cold tolerance to ensure stable yields over varied environments. This study was undertaken to screen six hundred and seventy-seven accessions of international wheat genetic resources to identify lines with high level of tolerance to salinity and cold environments. Based on the results of two years study in different agroecological locations, 51 accessions were classified as salt tolerant and 115 accessions were classified as cold tolerant. Of these, 35 accessions had good agronomic characteristics. Also, there were 39 genotypes with combined tolerance to cold as well as salinity. Thus, there were good lines which can be used directly or as parents for breeding wheat varieties for wide adaptation and high yield. Further analysis of the data showed that early genotypes had good cold tolerance but a poor salt tolerance. It was also observed that small number of both test spikelet and spikelet, short spike length and good seed-plump were positively associated with cold tolerance. Therefore, maturity and spike traits should be taken into considered when selecting wheat lines for wide adaptation breeding.

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Some wild species of the genus Oryza such as O. rufipogon and O. longistaminata show a high level of resistance to pests and diseases including rice blast (caused by Magnaporthe grisea). To transfer blast resistance from wild species into cultivatedvarieties (O. sativa), interspecific hybrids were produced and anther culture was used toaccelerate the procedure of resistance breeding. Anther culture efficiency depended onboth the medium and the genotype of the cultivated varieties and the wild species. Afterinoculation with a mixture of six strains with wide spectrum virulence, all the F1 hybridswere resistant to blast; the F2 plants segregated, from high resistance to susceptibility, anda similar result was obtained for the H1 and H2 plants. At the H3 stage, blast resistancetended to be stable and almost 100% of inoculated H5 plants were highly resistant to riceblast. For agronomic characteristics, the F2 and H1 showed segregation, but no significantdifferences were seen between the cultivated parents and the H2 to H5 generations. Theresults demonstrate that blast resistance genes can be transferred from wild rice speciesinto cultivated varieties through crossing and anther culture, and the H5 can be used asstable lines in future breeding programmes.

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Two segregating populations of doubled haploid (DH) wheat lines derived androgenetically from crosses ‘Svilena’ (susceptible) × A-38b-4-5-3-3 (highly resistant) and ‘Svilena’ × WWRN (moderately resistant to moderately susceptible) were characterized for resistance to common bunt. Disease incidence was evaluated after inoculation of seeds with a mixture of Tilletia foetida teliospores in two autumn sown field experiments. Two-gene model of inheritance of resistance in line A-38b-4-5-3-3 was suggested. The transgressive segregation in the latter population was indicative for a quantitative mode of inheritance. The DH lines were assessed for plant height, heading time and important yield components in a three-year field experiment without bunt infection. In both populations, transgressive segregation was observed for all agronomic characteristics. Although the disease incidence was positively correlated with most of the agronomic traits, genotypes combining bunt resistance with good yield potential were isolated from ‘Svilena’ × A-38b set of lines. These genotypes are valuable for breeding varieties designed for growing in low-input and organic farming systems. The two DH populations are suitable to be used for further studies on the genetic basis of bunt resistance.

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In order to increase genetic diversity in cereals, interspecific or even intergeneric crosses are worthwhile, especially wheat by rye crosses for triticale production. However, these crosses often fail due to inhibiting genes. To overcome this obstacle, crossability trait, present in a few wheat cultivars, can be transferred into other wheat lines of agronomical interest. Nevertheless, this transfer remains tedious through conventional backcrossing methods because it is a recessive trait, which requires selfing generations and complex evaluation by many crosses. Here, we present a marker-assisted backcrossing method to transfer this trait more quickly and easily. We chose to introduce the recessive crossability skr, located on chromosome 5BS and originating from Asian wheat, into Barok, a non-crossable French wheat cultivar, with good agronomic characteristics. Six molecular markers, close to the Skr locus, were used to check the transfer of the gene at each of the three backcrosses, without selfing generation nor crosses with rye. Finally, we crossed the predicted crossable lines with rye to validate their crossability. We obtained sixteen lines, morphologically similar to Barok, exhibiting high crossability rate (30%). The markers were thus efficient to transfer the skr crossability but they remain too far from the Skr locus to be considered as diagnostic markers. Indeed, genotyping and phenotyping on other wheat cultivars showed some discrepancies. Nevertheless, this opens the way to enhance genetic diversity more easily and to improve traits of agronomic interest in triticale or wheat as well as to study further barriers to intergeneric crosses.

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