Authors:Y. Gao, Q. Sun, R. Wang, J. Feng, F. Lin, N. Cui, X. Chen, S. Xu, Y. Bai, and X. Xu
Carter, A.H., Chen, X.M., Campbell, K.G. 2009. Identifying QTL for high-temperature adult-plant resistance to stripe rust ( Puccinia striiformis f. sp. tritici ) in the springwheat ( Triticum aestivum L
Authors:S. Singh, G. S. Sethi, and H. K. Chaudhary
Comparisons between androgenesis and maize-mediated haploid production efficiencies were made in six F1 genotypes each of winter × spring wheat and triticale × wheat crosses. The haploid status of the plantlets obtained was confirmed through cytological examination of the root tips. Much higher embryo formation (15.2%), haploid induction (8.7%) and doubled haploid production (8.3%) were obtained in the winter × spring wheat F1s through the wheat × maize system than by androgenesis (3.1%, 3.2 and 2.7%, respectively). Three of the triticale × wheat F1 genotypes failed to respond to androgenesis, while no haploids were recovered through the wheat × maize system in any of the six triticale × wheat F1s. Genotypic specificity, low callus induction and albinism reduced the efficiency of androgenesis both in winter × spring wheat and triticale × wheat hybrids. In all, the wheat × maize system proved to be better for winter × spring wheat hybrids and androgenesis for triticale × wheat hybrids.
Authors:Ariano Prestes, Barry Cunfer, and Jennifer Yocum
Thirty-two Brazilian spring wheats (
L. em. Thell.) were evaluated for partial resistance to Stagonospora blotch under greenhouse conditions to an isolate of
from the southeastern U.S. Incubation period was shortest (5.6 days) in the susceptible cultivar BR 4 and longest (12.7 days) in the resistant cultivar CEP 14. Latent period was significantly longer for CEP 14 than on any other cultivar except BR 38. Resistant wheats had latent periods that were 3–5 days longer than susceptible lines. Disease severity was negatively correlated (P < 0.01) with incubation period and latent period. Cultivars with long incubation period and long latent period also had a slow rate of disease progress. The widest range of response to
infection was for area under the disease progress curve (AUDPC). CEP 14 and BR32 had AUDPC values that were less than 25% of the values of seven cultivars with the highest AUDPC. CEP14 had the longest IP and LP and the lowest AUDPC, exceeding the next closest entry by almost 5% for each parameter. Ratings for components of partial resistance closely paralleled field ratings for resistance in southern Brazil. Because genotypes are generally well-adapted agronomically and responded similarly to an isolate representative of
in the southeastern U.S., resistant lines from southern Brazil may be useful in breeding programs in the southern U.S.
We characterized a representative set of 42 spring wheat cultivars from Russia and adjacent regions for 3 Vrn loci. The 42 genotypes were screened, along with 3 genotypes of known Vrn genes, using previously published genome-specific polymerase chain reaction (PCR) primers designed for detecting the presence or absence of dominant or recessive alleles of the major Vrn loci: Vrn-A1, Vrn-B1 and Vrn-D1. The dominant promoter duplication allele Vrn-A1a was present in 28 of 42 cultivars, whereas the promoter deletion allele Vrn-A1b was present in only 1 of the Russian cultivars (Triticum aestivum L. ‘Pyrothrix 28’). The intron deletion allele Vrn-A1c was not present in any tested cultivar. The dominant Vrn-D1 allele was found in 1 of the cultivars. Thirteen of the spring wheat cultivars tested here carry the recessive vrn-A1 allele. However, for 6 cultivars, there were inconsistencies between PCR data and genetic segregation analysis, showing the presence of the dominant Vrn-A1 gene. No inconsistencies were found in the case of Vrn-B1 locus. A new combination of specific primers allowed amplification of the common Vrn-B1a allele along with the novel Vrn-B1c allele, which was present in 17 of the studied cultivars (40%). Twenty-five cultivars (59%) had dominant alleles of Vrn-A1a and Vrn-B1 in combination. We showed the predominance of the Vrn-B1c allele among cultivars with monogenic control of vernalization in West Siberia and Kazakhstan. In the absence of epistatic effects of Vrn-A1, this allele causes an earlier heading time compared to Vrn-B1a, thereby avoiding early fall frosts. Suggestions are made concerning the origin and distribution of the Vrn-B1c allele among Russian spring wheats.
Lanzou Alkaline Stretched Noodles (LASN) was a traditional staple food in northwest China for nearly 90 years. LASN specialty wheat breeding has become an important target since 1990s. In order to discover the LASN specialty wheat quality requirement for allelic variations at
of northwest China spring wheats. Two northwest China spring wheat cultivars and 39 elite F6 breeding lines were adopted to determine the low-molecular-weight glutenin subunits (LMW-GS) composition by one step one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) basing on the protocol of Singh et al. (1991). The results showed that
were correlated to high protein content, high volume of SDS-sediment and super dough strength (W). While
was bad to dry gluten content and SDS-sediment as well as dough properties such as dough strength (W) and dough tenacity (P). Moreover,
has not significant influence on flour quality, but it has the negative effect on dough strength (W) and dough extensibility (L). As for LASN quality,
were beneficial alleles and
was unbeneficial alleles for LASN quality.