EXPRESSION OF VERNALIZATION GENES IN NEAR-ISOGENIC WHEAT LINES: METHODS OF VERNALIZATION

1979 ◽  
Vol 21 (3) ◽  
pp. 429-434 ◽  
Author(s):  
P. A. Salisbury ◽  
G. J. Berry ◽  
G. M. Halloran
Keyword(s):  
Reproductive Development ◽  
Triticum Aestivum L ◽  
Development Rate ◽  
Strong Positive Correlation ◽  
Near Isogenic Lines ◽  
Spikelet Number ◽  
Threshold Response ◽  
Graded Response ◽  
Vernalization Genes ◽  
Wheat Lines

Four near isogenic lines of wheat (Triticum aestivum L. em Thell.) were given various combinations of vernalization as imbibed seed and as growing plants. The combinations were designed so that all treatments had the equivalent of four weeks at 4 °C. In terms of days to anthesis the lines reacted in three different ways to increases in the proportion of the vernalization treatment given to the growing plant. Two lines exhibited a threshold response, another showed a graded response, while the remaining line was unaffected by the method of vernalization. The treatments affected final leaf number differently, and the usually strong positive correlation with days to anthesis was not evident. Similarly there was no evidence of a relationship between days to anthesis and spikelet number. The rate of reproductive development of varieties vernalized as imbibed seed will not necessarily reflect their development rate when vernalized naturally in the field. Hence wheat breeders adapting varieties to particular environments by the use of vernalization genes should evaluate their action under appropriate field conditions.

Agronomic characteristics of hard red spring wheat (Triticum aestivum L.) near-isogenic lines differing at the Waxy (Wx) locus

2015 ◽  
Vol 95 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Pierre Hucl ◽  
Adithya Ramachandran
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Waxy Gene ◽  
Near Isogenic Lines ◽  
Hard Red Spring Wheat ◽  
Isogenic Lines ◽  
Agronomic Characteristics ◽  
Wx Locus ◽  
Wheat Lines

Hucl, P. and Ramachandran, A. 2015. Agronomic characteristics of hard red spring wheat (Triticum aestivum L.) near-isogenic lines differing at the Waxy (Wx) locus. Can. J. Plant Sci. 95: 201–204. Null mutations of the Waxy gene in all three genomes of hexaploid wheat (Triticum aestivum L.) produce a waxy starch phenotype. The agronomic performance of 32 waxy, partially waxy and wild-type near-isogenic spring wheat lines and four check cultivars was assessed at two locations over three cropping seasons. Differences in grain yield, kernel weight and test weight among allelic groups were generally small. The results of our study suggest that no significantly negative effects are likely to occur in the commercial cultivation of partially waxy wheat lines derived from a CWRS cultivar.

scholarly journals Micromycetes of rhizosphere and phillosphere in the lines of wheat (Triticum aestivum L.) isogenic by VRN in relation to the development rate and productivity

2018 ◽  
Keyword(s):  
Field Experiments ◽  
Dominant Gene ◽  
Triticum Aestivum L ◽  
Development Rate ◽  
Soft Wheat ◽  
Species Structure ◽  
Vrn Genes ◽  
Fungal Propagules ◽  
Faster Development ◽  
Wheat Lines

The field experiments were performed in order to assess the micromycetes number and species composition in the rhizosphere and phillosphere of the Myronivska 808 soft wheat lines isogenic by VRN genes in relation to the rate of wheat development. It was established that the lines with dominant genes VRN-A1a and VRN-D1a came to the earing phase remarkably earlier than the line with the dominant gene VRN-B1a. In lines, which have faster development, the parameters of individual productivity were higher, and the content of protein in grains was lower than that in the line with lower development rate. The number of micromycetes species and their propagules in the rhizosphere of all wheat lines were higher than that in the phillosphere. As a result of the study of species diversity of NILs mycocenoses from rhizosphere of wheat 319 strains of micromycetes, belonging to 20 genera of Zygomycota and Ascomycota, were isolated in pure culture. The most species were identified from genera Fusaruim, Aspergillus, Рenicillium, Trichoderma, Mucor, and dark-pigmented micromycetes. It was established that in the rhizosphere the maximum number of micromycetes species and propagules was associated with the isolines of VRN-A1a and VRN-D1a, which showed an accelerated development, while the minimum fungi diversity occurred in the root soil of the VRN-B1a line. The phillosphere of the plant ears in all studied wheat isolines appeared to be rather poor in microscopic fungi: only 27 strains belonging to 6 genera were identified. Potential phytopathogens – representatives of the genus Fusarium were found on the surface of the plant ears of all lines, and in the phillosphere of plants of VRN-A1a line there were also representatives of dark pigmented micromycetes. The number of fungal propagules was also maximal for isolines with accelerated rates of development – VRN-A1a and VRN-D1a, and minimal for plants of VRN-B1a isoline. Thus, population density of micromycetes and their species structure, both in rhizosphere and on plant ears, correlated with the rate of development of wheat lines, which was determined by the dominant/recessive state of the VRN genes. Therefore it can be assumed that VRN genes are indirectly involved in the formation and functioning of the mycosenoses of the studied isogenic lines of soft wheat, particularly via their participation in the regulation of physiological and biochemical processes.

Comparative analysis of genetic background in eight near-isogenic wheat lines with different H genes conferring resistance to Hessian fly

Genome ◽  
2011 ◽  
Vol 54 (1) ◽  
pp. 81-89 ◽  
Author(s):  
S. S. Xu ◽  
C. G. Chu ◽  
M. O. Harris ◽  
C. E. Williams
Keyword(s):  
Genetic Background ◽  
Genetic Similarity ◽  
Triticum Aestivum L ◽  
Hessian Fly ◽  
Pedigree Analysis ◽  
Recurrent Parent ◽  
Linkage Drag ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
H Gene

Near-isogenic lines (NILs) are useful for plant genetic and genomic studies. However, the strength of conclusions from such studies depends on the similarity of the NILs’ genetic backgrounds. In this study, we investigated the genetic similarity for a set of NILs developed in the 1990s to study gene-for-gene interactions between wheat ( Triticum aestivum L.) and the Hessian fly ( Mayetiola destructor (Say)), an important pest of wheat. Each of the eight NILs carries a single H resistance gene and was created by successive backcrossing for two to six generations to susceptible T. aestivum ‘Newton’. We generated 256 target region amplification polymorphism (TRAP) markers and used them to calculate genetic similarity, expressed by the Nei and Li (NL) coefficient. Six of the NILs (H3, H5, H6, H9, H11, and H13) had the highly uniform genetic background of Newton, with NL coefficients from 0.97 to 0.99. However, genotypes with H10 or H12 were less similar to Newton, with NL coefficients of 0.86 and 0.93, respectively. Cluster analysis based on NL coefficients and pedigree analysis showed that the genetic similarity between each of the NILs and Newton was affected by both the number of backcrosses and the genetic similarity between Newton and the H gene donors. We thus generated an equation to predict the number of required backcrosses, given varying similarity of donor and recurrent parent. We also investigated whether the genetic residues of the donor parents that remained in the NILs were related to linkage drag. By using a complete set of ‘Chinese Spring’ nullisomic-tetrasomic lines, one third of the TRAP markers that showed polymorphism between the NILs and Newton were assigned to a specific chromosome. All of the assigned markers were located on chromosomes other than the chromosome carrying the H gene, suggesting that the genetic residues detected in this study were not due to linkage drag. Results will aid in the development and use of near-isogenic lines for studies of the functional genomics of wheat.

Histological studies on host-cell necrosis conditioned by the Sr6 gene for resistance in wheat to stem rust

1977 ◽  
Vol 55 (11) ◽  
pp. 1445-1452 ◽  
Author(s):  
D. J. Samborski ◽  
W. K. Kim ◽  
R. Rohringer ◽  
N. K. Howes ◽  
R. J. Baker
Keyword(s):  
Triticum Aestivum ◽  
Stem Rust ◽  
Fungal Growth ◽  
Triticum Aestivum L ◽  
Host Cells ◽  
Puccinia Graminis ◽  
Near Isogenic Lines ◽  
Cell Necrosis ◽  
Calcofluor White ◽  
Histological Studies

Seedlings of resistant (Sr6) and susceptible (sr6) near-isogenic lines of wheat (Triticum aestivum L.) were inoculated with a race of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) that was avirulent on the line with Sr6 and they were kept at 19, 25, 26, and 27 °C. Fluorescence microscopy was used to detect autofluorescing necrotic host cells and rust colonies after these were stained with a fiuorochrome (Calcofluor White M2R New).In leaves containing the Sr6 gene, a smaller percentage of colonies grown at 25 °C had necrotic cells associated with them than those that were grown at 19 °C. The incidence of colony-associated necrosis in these leaves could be further reduced by increasing the temperature to 26 °C and 27 °C. Similarly, the number of necrotic host cells per colony decreased with an increase in temperature. Colonies in genotypically resistant leaves were usually smaller than those in genotypically susceptible leaves, but the differences in colony sizes between these two lines decreased at the higher temperatures.When infected plants containing the Sr6 gene were kept for varying times at 25 °C and then were transferred to 19 °C, there was significantly less fungal growth and more necrosis than in plants kept continuously at 25 °C. This necrosis occurred largely in those cells that were invaded after the transfer to 19 °C, when the Sr6 gene was activated.

Day-length influence on reproductive development and tillering in ‘Fergus’ barley

1975 ◽  
Vol 53 (23) ◽  
pp. 2770-2775 ◽  
Author(s):  
D. T. Fairey ◽  
L. A. Hunt ◽  
N. C. Stoskopf
Keyword(s):  
Hordeum Vulgare ◽  
Reproductive Development ◽  
Tiller Number ◽  
Day Length ◽  
Floral Initiation ◽  
Internode Elongation ◽  
Spikelet Number ◽  
Hordeum Vulgare L ◽  
Initial Formation ◽  
Double Ridge

Effects of variation in day length on spikelet and tiller development were studied in a two-rowed barley, Hordeum vulgare L. cultivar ‘Fergus.’ Spikelet number and the length of the spikelet-forming phase increased with progressive reductions in day length from 24 to 12 h. However, increases in spikelet number were offset by abortion of spikelet primordia during spikelet differentiation and elongation of the stem internodes. Floral initiation occurred at all day lengths, but intemode elongation and heading were markedly delayed at 12 h. The cessation of spikelet initial formation and the beginning of internode elongation did not occur simultaneously in any day length. The latter began just before or at double ridge formation.Tiller numbers were highest at 12 h and progressively decreased in longer day lengths. Each plant produced four primary tillers at all day lengths, and differences in tiller number were accounted for by secondary and tertiary tiller production.

Agronomic evaluation of a tiller inhibition gene (tin) in wheat. I. Effect on yield, yield components, and grain protein

2005 ◽  
Vol 56 (2) ◽  
pp. 169 ◽  
Author(s):  
B. L. Duggan ◽  
R. A. Richards ◽  
A. F. van Herwaarden ◽  
N. A. Fettell
Keyword(s):  
Triticum Aestivum L ◽  
Kernel Weight ◽  
Grain Protein ◽  
Terminal Drought ◽  
Spike Number ◽  
Effect On Yield ◽  
Productive Tiller ◽  
Wheat Lines ◽  
Positive Effect ◽  
Yield Penalty

Reduced tillering cereals have been proposed as being advantageous under terminal drought conditions through their reported reduction in non-productive tiller number and reduced soil water use prior to anthesis. This study was conducted to determine whether wheat (Triticum aestivum L.) lines containing the tiller inhibition (tin) gene have a yield penalty over their commercial near-isogenic counterparts. A terminal drought was experienced in all experiments. The effects of the tin gene were investigated in 4 different near-isogenic pairs of lines grown at 2 sowing densities at 4 locations in the eastern Australian wheatbelt over a 3-year period. Averaged over all experiments and lines, grain yield was unaffected by the presence of the tin gene. However, the highest yielding line contained the tin gene and its yield was 5% higher than all other lines. Averaged across the different genetic backgrounds, the tin gene decreased fertile spike number by 11%, increased the number of kernels/spike by 9%, and there was a 2% increase in kernel weight. The tin gene increased the harvest index by an average of 0.02, whereas above-ground biomass was reduced by 7%. Increasing sowing density from 50 to 100 kg/ha had little influence on yield or yield-related characteristics in both the restricted tillering and freely tillering lines. There was an interaction between sowing rate and the presence of the tin gene on yield, with tin lines yielding 0.2 t/ha more than the freely tillering lines at the higher sowing rate, whereas there was no effect at the lower sowing rate. The response of several lines containing the tin gene to nitrogen fertiliser was also investigated at 2 sites. Nitrogen increased spike number in all lines but the number remained around 20% less than in the freely tillering cultivars. The yield of wheat lines containing the tin gene was 6% greater than their near-isogenic pairs where nitrogen status was high in the presence of terminal drought. Grain protein concentration was unaffected by the presence of the tin gene at high grain protein sites, whereas at lower grain protein sites it had a positive effect.

Construction of comparative genetic maps of two 4Bs.4Bl-5Rl translocations in bread wheat (Triticum aestivum L.)

Genome ◽  
2006 ◽  
Vol 49 (7) ◽  
pp. 729-734 ◽  
Author(s):  
R C Leach ◽  
I S Dundas ◽  
A Houben
Keyword(s):  
Triticum Aestivum ◽  
Bread Wheat ◽  
Rflp Analysis ◽  
Triticum Aestivum L ◽  
Genetic Maps ◽  
Homoeologous Group ◽  
Group 4 ◽  
Translocation Breakpoints ◽  
Group 5 ◽  
Wheat Lines

The physical length of the rye segment of a 4BS.4BL–5RL translocation derived from the Cornell Wheat Selection 82a1-2-4-7 in a Triticum aestivum 'Chinese Spring' background was measured using genomic in situ hybridization (GISH) and found to be 16% of the long arm. The size of this translocation was similar to previously published GISH measurements of another 4BS.4BL–5RL translocation in a Triticum aestivum 'Viking' wheat background. Molecular maps of both 4BS.4BL–5RL translocations for 2 different wheat backgrounds were developed using RFLP analysis. The locations of the translocation breakpoints of the 2 4BS.4BL–5RL translocations were similar even though they arose in different populations. This suggests a unique property of the region at or near the translocation breakpoint that could be associated with their similarity and spontaneous formation. These segments of rye chromosome 5 also contain a gene for copper efficiency that improves the wheat's ability to cope with low-copper soils. Genetic markers in these maps can also be used to screen for copper efficiency in bread wheat lines derived from the Cornell Wheat Selection 82a1 2-4-7.Key words: Triticum aestivum, wheat–rye translocation, homoeologous group 4, homoeologous group 5, GISH, comparative map, copper efficiency, hairy peduncle.

scholarly journals Down-expression of TaPIN1s Increases the Tiller Number and Grain Yield in Wheat

2021 ◽  
Author(s):  
Fu Quan Yao ◽  
Xiao Hui Li ◽  
He Wang ◽  
Yu Ning Song ◽  
Zhong Qing Li ◽  
...  
Keyword(s):  
Grain Yield ◽  
Expression Patterns ◽  
Protein Structures ◽  
Triticum Aestivum L ◽  
Transgenic Wheat ◽  
Tiller Number ◽  
Panicle Number ◽  
In The Wild ◽  
Wheat Lines ◽  
Grain Number Per Panicle

Abstract Background: Tiller number is a factor determining panicle number and grain yield in wheat (Triticum aestivum L.). Auxin plays an important role in the regulation of branch production. PIN-FORMED 1 (PIN1), an auxin efflux carrier, plays a role in the regulation of tiller number in rice (Oryza sativa); however, little is known on the roles of PIN1 in wheat. Results: Nine homologs of TaPIN1 genes were identified in wheat, of which TaPIN1-6 genes showed higher expression in the stem apex and young leaf in wheat, and the TaPIN1-6a protein was localized in the plasma membrane. The down-expression of TaPIN1s increased the tiller number in TaPIN1-RNA interference (TaPIN1-RNAi) transgenic wheat plants, indicating that auxin might mediate the axillary bud production. By contrast, the spikelet number, grain number per panicle, and the 1000-grain weight were decreased in the TaPIN1-RNAi transgenic wheat plants compared with those in the wild type. Conclusions: Phylogenetic analysis and expression patterns of nine TaPIN1 genes, and their protein structures and subcellular localization of TaPIN1-6a protein were analyzed. Down-regulated expression of TaPIN1 genes increased the tiller numbers of transgenic wheat lines. Our study suggests that TaPIN1s is required for the regulation of grain yield in wheat.

Rumen digestibility in dairy cows of starch in near-isogenic lines of wheat

1999 ◽  
Vol 1999 ◽  
pp. 90-90
Author(s):  
P.C. Garnsworthy ◽  
J. Wiseman
Keyword(s):  
Near Isogenic Lines ◽  
Limited Information ◽  
Wheat Varieties ◽  
Isogenic Lines ◽  
Relative Value ◽  
Metabolisable Energy ◽  
Growing Conditions ◽  
The Uk ◽  
Wheat Lines ◽  
Agronomic Conditions

Wheat is a good source of carbohydrates for ruminants, and recent low prices in the UK suggest that usage is likely to increase. However, there is a shortage of information on the digestibility of wheat in the rumen. Such information is vital for predicting the relative value of wheat as a source of fermentable metabolisable energy or by-pass starch. Digestibility is likely to be affected by growing conditions and genetics. Genetic differences are found between wheat varieties, but comparisons of named varieties yield limited information because many characteristics vary simultaneously. This problem can be overcome by using near-isogenic lines of wheat that vary only in a limited number of known characteristics. The objective of this study was to determine the rumen digestion characteristics of different near-isogenic wheat lines grown under the same agronomic conditions.

Anthranilate Synthase and Chorismate Mutase Activities in Stem Rust-Inoculated and Elicitor-Treated Resistant, Moderately Resistant, and Susceptible Near-Isogenic Wheat Lines

1995 ◽  
Vol 50 (1-2) ◽  
pp. 54-60 ◽  
Author(s):  
Claudia Bücker ◽  
Barbara Witte ◽  
Ursula Windmüller ◽  
Hans J. Grambow
Keyword(s):  
Stem Rust ◽  
Rust Fungus ◽  
Triticum Aestivum L ◽  
Enzyme Activation ◽  
Chorismate Mutase ◽  
Anthranilate Synthase ◽  
Resistance Response ◽  
Tryptophan Pathway ◽  
Wheat Lines ◽  
Moderately Resistant

Abstract Anthranilate synthase and chorismate mutase activities which control the flow of substrate from chorismate into the tryptophan pathway and into the phenylalanine/tyrosine pathway, respectively, were examined in three near isogenic wheat lines of Triticum aestivum L. (cv. Prelude Sr 5, highly resistant to stem rust infection; cv. Prelude Sr 24, moderately resistant; cv. Prelude srx, susceptible). The activities of both enzymes were found to increase in re­sponse to inoculation with the stem rust fungus Puccinia graminis f. sp. tritici or treatment with Pgt elicitor. Thus, both the tryptophan branch and the phenylalanine branch appear to contribute to the resistance response in wheat leaves. Only the cytosolic but not the plastidic fraction of the enzyme activities appears to be affected by fungal infection or elicitor treat­ment. Some differences with respect to degree and time dependency of enzyme activation were noticed between the three wheat lines following inoculation but not after treatment with the Pgt elicitor.

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