Authors:X.L. Qi, X.F. Li, F. He, L.Q. Hu, Y.G. Bao, J.R. Gao, and H.G. Wang
Thinopyrum intermedium, which has many useful traits, is valuable for wheat breeding. A new wheat-Thinopyrum addition line, SN100109, was developed from the progeny of common wheat cultivar Yannong 15 and Th. intermedium. It was resistant to most races of Blumeria graminis f. sp tritici (Bgt), which caused powdery mildew in wheat, and its reactions were different from the reactions of gene Pm40 and Pm43. Genomic in situ hybridization (GISH) and molecular marker analysis were used to identify the genomic composition of SN100109. GISH results showed that SN100109 was a wheat-Th. intermedium disomic addition line containing one pair of J chromosomes, and the resistance gene was located on the alien additional chromosomes of SN100109. And four molecular markers BE425942, BF482714, Xgdm93 and BV679214 which were assigned to homologous group 2, were specific molecular markers of the additional chromosomes. All the results indicated that SN100109 contained one pair of 2J chromosomes. SN100109 can be used as a novel germplasm source for introducing powdery mildew resistance genes to wheat in breeding programs.
Authors:X. J. Li, X. G. Hu, T. Z. Hu, G. Li, Z. G. Ru, L. L. Zhang, and Y. M. Lang
Du , W. , Wang , J. , Lu , M. , Sun , S. , Chen , X. , Zhao , J. , Yang , Q. , Wu , J.
2013 a. Molecular cytogenetic identification of a wheat- Psathyrostachys huashanica Keng 5Ns disomic additionline with stripe rust
Authors:S. Dulai, I. Molnár, B. Haló, and M. Molnár-Láng
The photosynthetic responses induced by NaCl were investigated in the 7H Asakaze komugi/Manas wheat/barley addition line developed in the Agricultural Research Institute, Martonvásár, Hungary, in the wheat (Triticum aestivum L.) cv. Asakaze komugi (Akom) and wheat line Martonvásári 9 kr1 (Mv9kr1) and in the barley (Hordeum vulgare L.) cv. Manas. An increase in the NaCl concentration of the nutrient solution to 200 mmol L−1 resulted in considerable stomatal closure and a decreased net CO2 assimilation rate (A) in the wheat genotypes, while the changes in these parameters were less significant for barley and the 7H addition line. Parallel with this, a relatively high non-stomatal limitation (Lm) of A was observed in wheat genotypes, which was not significant in Manas or the wheat-barley addition line at this level of salt stress. At severe stress (300 mM L−1 NaCl concentration) A and stomatal conductance were strongly inhibited in all the genotypes examined; however, Lm was less significant in the addition line and its parental wheat genotype. These preliminary results suggest that the 7H Akom/Manas addition line might be a good candidate for improving the salt tolerance of wheat in the future, and encourage further detailed physiological analysis of this addition line.
Authors:X. Song, G. Li, H. Zhan, C. Liu, and Z. Yang
Stripe rust, caused by Puccinia striiformis f. sp. tritici, was one of the most disaster foliar diseases for wheat-growing areas of the world. Thinopyrum intermedium has provided novel resistance genes to multi-fungal disease, and new wheat-Th. intermedium derivatives for stripe rust resistance still need to develop for wheat breeding. Wheat line X484-3 was selected from a cross between wheat line MY11 and wheat-Th. intermedium ssp. trichophorum partial amphiploid TE-1508, and was characterized by genomic in situ hybridization (GISH) and functional molecular markers. Chromosome counting revealed that the X484-3 was 2n = 44 and GISH analysis using Pseudoroegneria spicata genomic DNAas a probe demonstrated that X484-3 contained a pair of St-chromosomes from Th. intermedium donor parents. The functional molecular markers confirmed that introduced St-chromosomes belonging to linkage group 7, indicating that line X484-3 was a 7St addition line. The resistance observation displayed that the introduced Th. intermedium ssp. trichophorum derived chromosomes 7St were responsible for the stripe rust resistances at adult plant. The identified wheat-Th. intermedium chromosome 7St addition line X484-3 can be used as a donor in wheat breeding for stripe rust resistance.
The influence of individual
chromosomes on callus induction and morphogenic ability of
cultivated immature embryos of wheat/
addition lines was studied. An euploid form of cultivar Chinese Spring of
(2n=42), AABBDD, seven disomic addition lines of Chinese Spring with chromosomes of
(2n=14) EE, and the amphidiploid Chinese Spring/
(2n=56), AABBDDEE, were used as donor plants. Immature 14 days old embryos were
cultivated. A relatively high number of calli were issued in embryocultures of all studied lines without significant variations among them. Relatively lower callus induction rate occurred only in the addition line containing 5E chromosome. Substantial differences were observed between the lines in respect to the number of both initiated morphogenic calli and regenerants obtained. The highest number of morphogenic calli and regenerants was obtained in cultures of lines containing the
chromosomes 1E and 6E and the lowest one — in the 4E addition line. The data suggest that the effect of
chromosomes could be due to existence of homeoalleles in those chromosomes, but the presence in
genome of genes and alleles affecting specifically
response can not be excluded either.
Authors:C. Wang, L. Li, X. Zhang, Q. Gao, R. Wang, and D. An
Molecular markers are important tools that have been used to identify the short arm of rye chromosome 1R (1RS) which contains many useful genes introgressed into wheat background. Wheat expressed sequence tag (EST) sequences are valuable for developing molecular markers since ESTs are derived from gene transcripts and more likely to be conserved between wheat and its relative species. In the present study, 35 sequence-tagged site (STS) primers were designed based on EST sequences distributed on homology group 1 chromosomes of
and used to screen specific markers for chromosome 1RS of
. Two primer pairs different from the early studies, STS
, which amplified a 1680-bp and a 1750-bp fragment, and STS
, which produced a 850-bp fragment from rye genome, were proved to be specific to chromosome 1RS since the corresponding fragments were only amplified from 1R chromosome addition line and wheat-rye lines with chromosome 1RS, but not from wheat-rye 2R-7R chromosome addition lines and the other lines lacking chromosome 1RS. Eleven wheat-rye lines derived from ‘Xiaoyan 6’ and ‘German White’ were used to test the presence of specific markers for 1RS. The specific fragments of 1RS were amplified in 4 wheat-rye lines, but not in the other lines. The testing results using EST-STS markers of 1RS were consistent with those obtained from fluorescence
hybridization (FISH), suggesting that these markers specific to 1RS could be used in marker-assisted selection (MAS) for incorporating 1RS into wheat cultivars in breeding.
Authors:E. Farshadfar, R. Mohammadi, M. Aghaee, and J. Sutka
Water deficiency is a major constraint in wheat production and the most important contributor to yield reduction in the semiarid regions of the world. species related to wheat are valuable genetic sources for different traits including resistance/tolerance to biotic and abiotic stresses. To locate the genes controlling the physiological and agronomic criteria of drought tolerance, disomic addition lines of secale cereale cv. Imperial (donor) into the genetic background of Triticum aestivum cv. Chinese Spring (recipient) were tested under field, greenhouse and laboratory conditions. Disomic addition lines exhibited significant differences for relative water content (RWC), relative water loss (RWL), water use efficiency (WUE) and stomatal resistance (SR), indicating the presence of genetic variation and the possibility of selection for improving drought tolerance. Three physiological variables, RWL, WUE and SR, with high correlation with the stress tolerance index (STI) and germination stress index (GSI), contributed 69.7% to the variability of yield under stress (Ys) in the regression equation. Based on the physiological multiple selection index (MSI) most of the QTLs controlling physiological indices of drought tolerance were located on chromosomes 3R, 5R and 7R. The contribution of addition line 7R to the MSI was 47%. The evaluation of disomic addition lines for STI and GSI revealed that most of the QTLs involved in these quantitative criteria of drought tolerance are located on 3R and 7R. Cluster analysis and three dimensional plots of Ys, yield potential (Yp) and MSI indicated that 3R and 7R are the most important chromosomes carrying useful genes for improving drought tolerance.