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1.
Aluminum limits wheat (Triticum aestivum L.) yields on acid soils. An aluminum-tolerant, N-genome Triticum species was used to produce amphiploids, which were tested lor tolerance to 0.44 mM aluminum in solution, to assess the possibility of transferring tolerance to bread wheat. Two types of amphiploids, having the N-genomc (Triticum uniaristatum) in common, were produced by treating three different Triticum ventricosum (DDNN) ×Triticum turgidum (AABB) hybrids and a single Triticum ventricosun×Triticum timopheevii (AABB) hybrid with colchicine. It would appear that the N-genome amphiploids can be utilized to transfer tolerance to aluminum to cultivated Triticum species and to study the genetics of tolerance in the N genome. 相似文献
2.
Biochemical, molecular, and cytogenetic technologies for characterizing 1RS in wheat: A review 总被引：4，自引：0，他引：4
Chromosome arm 1RS of rye ( Secale cereale L.), when transferred to wheat ( Triticum sp.), significantly influences variety
performance, because it carries genes for resistance to disease and insect pathogens. Inserted into wheat, 1RS also promotes
haploid production, affects end-product quality, and sometimes affects yield. Therefore, its detection by breeders and geneticists
is important. The entire 1RS arm is present in chromosome substitutions and in Robertsonian translocations involving chromosomes
1A, 1B, or 1D of wheat. In recombinant lines, a segment of 1RS has been exchanged with a segment of a group-1 wheat chromosome.
Determining the wheat chromosome arm involved in a translocation, the source of rye chromatin, and the amount of 1RS chromatin
introduced is necessary for a complete characterization of the introgressed segment. Biochemical, molecular, and cytogenetic
technologies are described which enable such a characterization of 1RS in wheat. Examples of using gel electrophoresis, high-performance
liquid chromatography, monoclonal antibodies, rye-specific molecular probes, RFLP and PCR assays, chromosome banding, in situ
hybridization, and flow cytometry are provided. A comparison of these technologies is made and the advantages and disadvantages
of each technology are discussed relative to modern wheat breeding efforts.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
D. R. Kandel K. D. Glover W. A. Berzonsky J. L. Gonzalez-Hernandez S. Ali S. Chao 《Journal of Crop Improvement》2017,31(6):879-892
Hybrid necrosis in wheat (Triticum aestivum L.) is the premature death of leaves or plants caused by the interaction of two dominant complementary genes, Ne1 and Ne2, located on chromosomes 5B and 2B, respectively. We examined allelic interaction effects of necrosis alleles using simple sequence repeat (SSR) markers in F2 populations derived from crossing the cultivar “Alsen” with a synthetic hexaploid “TA4152-37”. The SSR marker Xbarc7 was linked at a distance of 3 cM to the quantitative trait loci (QTL) located on chromosome 2B, and Xgwm639 was 11 cM from the 5B QTL. A significant additive by additive epistatic interaction was detected between Ne1 and Ne2 QTL, and the results suggest that Alsen possesses a moderate necrosis allele, Ne2m; whereas, TA4152-37 possesses a moderate necrosis allele, Ne1m. The Ne2m allele had a stronger effect than the Ne1m allele, and a total of 94.6% of phenotypic variance was explained by these genes and their interactions. This demonstrates the strong phenotypic effect due to even moderate necrosis alleles, and emphasizes the need for breeders to accurately predict and identify hybrids that will result in necrosis. 相似文献
4.
A comparison of marker-assisted and phenotypic selection for high grain protein content in spring wheat 总被引：3，自引：0，他引：3
Wheat grain protein content (GPC) is a primary end-use quality determinant for hard spring wheat (Triticum aestivum L.), and marker-assisted selection (MAS) could help plant breeders to develop high GPC cultivars. Two experiments were conducted using two populations developed by crossing low GPC cultivars (Ember) and (McVey) with (Glupro), which contains a high GPC QTL from Triticum dicoccoides (DIC). In one experiment, MAS and phenotypic selection (PS) were employed to select high GPC genotypes, and the selected genotypes were grown in six North Dakota (ND), USA environments. In a second experiment, molecular markers were used to select BC2F2 plants from each marker class for the DIC allele from each population. These plants were twice self-pollinated to produce BC2F4 plants, which were grown in single ND and Minnesota (MN) environments. Mean GPC was highest among lines using PS at two environments and not significantly different between MAS and PS in the other four environments. Lines presumably homozygous for DIC alleles had significantly higher GPC than their respective low GPC parents. The phenotypic GPC variation explained by the markers (r
2) was 30% at the ND and 15% at the MN environment. The use of PS was as effective as MAS in selecting for high GPC genotypes and more effective in some environments. This likely can be attributed to PS enabling selection for both the major QTL and other genes contributing to GPC. The use of molecular markers might be more advantageous for transferring the high GPC DIC QTL in a backcrossing program during parent development. 相似文献
5.
A total of 523 accessions of 25 Triticum species were screened for tolerance of aluminum in solution. Only 22 accessions were identified with some root re growth following exposure w culture solutions containing 12 ppm aluminum. Interestingly, 15 of these 22 accessions were species with the Un genome (T. uniaristatum). The level of aluminum tolerance of none of these 22 accessions is as high as that of the cultivar ‘Atlas 66’. 相似文献
6.
Doubled haploid (DH) lines are important in wheat (Triticum aestivum L.) breeding, and haploids produced via maize pollination precede DH line development. Although maize pollination has proven
reliable and broadly applicable to wheat, its success is determined by the wheat and maize genotypes employed. A wheat genotype
consisting of nuclear and cytoplasm components predisposing it to parthenogenesis was compared with three other genotypes,
each possessing only one or neither component necessary for parthenogenesis. In a glasshouse experiment, each genotype was
pollinated with maize and subsequently treated with a2,4-Dichlorophenoxyacetic Acid (2,4-D) solution to determine if parthenogenesis
affected embryo formation frequency (EFF)and haploid formation efficiency (HFE). Wheat genotypes were also treated with the2,4-D
solution alone to determine if embryos and haploid plants could be produced in vivo without maize pollination. ‘Salmon(K)’,
a parthenogenetic genotype consisting of a Salmon 1BL.1RS nucleus in a Ae. kotschyii cytoplasm, had a mean EFF of 32%; whereas, the non-parthenogenetic genotypes had mean EFF calculations ranging from 7 to
21%. Mean HFE for Salmon(K) was not significantly different than the mean HFE for non-parthenogenetic Salmon; however, EFF
and HFE calculations for Salmon(K) and Salmon, each with a 1BL.1RS translocation, were generally higher than calculations
for genotypes without the translocation. Salmon(K) was the only genotype to produce a 3% or higher EFF and HFE after treatment
with 2,4-D alone. Parthenogenesis significantly affected the frequency at which embryos were produced after pollination with
maize and the frequency at which embryos and haploid plants were produced after treatment with 2,4-D alone.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Yield and quality reductions caused by Fusarium head blight (FHB) have spurred spring wheat (Triticum aestivum L.) breeders to identify and develop new sources of host plant resistance. Four wheat synthetic hexaploids (×Aegilotriticum sp.) were developed, each having a quantitative trait locus (QTL), Qfhs.ndsu‐3AS, providing FHB resistance from Triticum turgidum L. var. dicoccoides chromosome 3A. Synthetics were produced by hybridizing a ‘Langdon’‐T. dicoccoides‐ recombinant chromosome 3A substitution line (2n = 4x = 28, AABB with two accessions of T. tauschii (2n= 2x = 14, DD). Synthetics were inoculated and evaluated for FHB resistance in two separate greenhouse seasons. One synthetic, 01NDSWG‐5, exhibited FHB severity ratings of 36% and 32% in the separate seasons, compared with ratings of 9% and 30% for ‘Alsen’, a FHB‐resistant spring cultivar, and ratings of 70% and 96% for ‘McNeal’, a susceptible spring cultivar, respectively. Synthetic × Alsen backcross‐derived lines were produced to initiate combining different sources of FHB resistance. 相似文献
8.
9.
Ricardo A．Sooncini MVD 《国外畜牧学(猪与禽)》2012,32(7)
3预防沙门氏菌传播的措施
3.1卫生和消毒
在引进新一批鸡群前,所有鸡舍和器具必须进行清洁消毒,特别是在前一批鸡群为沙门氏菌阳性的情况下,清洁消毒就更有必要.卫生措施的有效性可通过严格的细菌学定量检测验证,要求肠道细菌计数小于103个/25 m2. 相似文献
10.
F. E. Dowell E. B. Maghirang R. A. Graybosch W. A. Berzonsky S. R. Delwiche 《Cereal Chemistry》2009,86(3):251-255
An automated single kernel near‐infrared (NIR) sorting system was used to separate single wheat (Triticum aestivum L.) kernels with amylose‐free (waxy) starch from reduced‐amylose (partial waxy) or wild‐type wheat kernels. Waxy kernels of hexaploid wheat are null for the granule‐bound starch synthase alleles at all three Wx gene loci; partial waxy kernels have at least one null and one functional allele. Wild‐type kernels have three functional alleles. Our results demonstrate that automated single kernel NIR technology can be used to select waxy kernels from segregating breeding lines or to purify advanced breeding lines for the low‐amylose kernel trait. Calibrations based on either amylose content or the waxy trait performed similarly. Also, a calibration developed using the amylose content of waxy, partial waxy, and wild‐type durum (T. turgidum L. var durum) wheat enabled adequate sorting for hard red winter and hard red spring wheat with no modifications. Regression coefficients indicated that absorption by starch in the NIR region contributed to the classification models. Single kernel NIR technology offers significant benefits to breeding programs that are developing wheat with amylose‐free starches. 相似文献