Genetic control of sodium exclusion in durum wheat

2003 ◽  
Vol 54 (7) ◽  
pp. 627 ◽  
Author(s):  
Rana Munns ◽  
Gregory J. Rebetzke ◽  
Shazia Husain ◽  
Richard A. James ◽  
Ray A. Hare
Keyword(s):  
Durum Wheat ◽  
Genetic Control ◽  
Genotypic Variation ◽  
Genetic Effect ◽  
Progeny Testing ◽  
High Accumulation ◽  
Wheat Landrace ◽  
F2 Generation ◽  
Sodium Exclusion ◽  
Na Uptake

Salt tolerance in the genus Triticum is associated with low accumulation of Na+ in leaves. Durum and other tetraploid wheats generally have high accumulation of Na+ relative to bread wheat, and are salt sensitive, but a durum wheat landrace, Line 149, was found to have unusually low leaf Na+ accumulation. Populations were developed from crosses between 149 and the high Na+ accumulation variety Tamaroi, as well as between 149 and a durum wheat landrace with very high Na+ accumulation, Line 141. The third leaf of parental lines, F1, F2, and low- and high-selected F2:3 progeny was assayed for Na+ uptake when grown in 150 mM NaCl. Sodium concentrations were significantly (P < 0.01) lower in the low Na+ uptake Line 149 compared with high Na+ uptake Tamaroi (5-fold greater Na+ accumulation) and Line 141 (7-fold greater Na+ accumulation). There was no evidence of any maternal genetic effect on Na+ accumulation. The F1 progeny mean was intermediate to the mid- and low-parent means, suggesting incomplete dominance gene action. Progeny in the F2 generation of both populations segregated for Na+ accumulation in a 15 (low Na+) : 1 (high Na+) ratio (χ215:1 = 0.27 and 0.46, P > 0.50n.s. for 149/Tamaroi and 149/141, respectively), indicating duplicate dominance epistasis arising from segregation of 2 interacting dominant genes. Small yet significant (P < 0.01) genotypic variation was also observed for minor genes affecting Na+ accumulation. Realised heritabilities were moderate to high (h2R = 0.43–0.90) across populations, indicating good response to selection for low Na+ accumulation in the F2 generation. The simple genetic control of Na+ accumulation suggests relative ease of selection of lines with low Na+ accumulation. However, presence of dominance will require selection to be delayed until after 1 or 2 generations of inbreeding, or after progeny-testing of selected low Na+ accumulation families.

Inheritance of coleoptile tiller appearance and size in wheat

2008 ◽  
Vol 59 (9) ◽  
pp. 863 ◽  
Author(s):  
G. J. Rebetzke ◽  
C. López-Castañeda ◽  
T. L. Botwright Acuña ◽  
A. G. Condon ◽  
R. A. Richards
Keyword(s):  
Leaf Area ◽  
Genetic Control ◽  
Genotypic Variation ◽  
Growth Stages ◽  
Genotypic Differences ◽  
Progeny Testing ◽  
Plant Leaf ◽  
Generation Means ◽  
Selection For ◽  
Seedling Leaf

Selection for rapid leaf area growth has the potential to increase wheat biomass, and both water-use efficiency and weed competitiveness early in the season. Several morphological components contribute to increased seedling leaf area, including rapid seedling emergence and production of longer, wider leaves. Early emergence of a large coleoptile tiller has also been demonstrated to increase plant leaf area and biomass in wheat and other grass seedlings. Yet little is known of the extent and nature of genotypic variation for coleoptile tiller growth in wheat. A random set of 35 wheat, barley, and triticale genotypes was evaluated in glasshouse and outdoor studies for seedling characteristics, including coleoptile tiller growth and total plant leaf area. Coleoptile tillers were produced more reliably for seedlings grown outdoors and when supplied with additional soil nitrogen. Genotypic differences in coleoptile tiller frequency and leaf area were large, ranging from 0 to 78% and from 0.0 to 1.4 cm2, respectively at very early growth stages. Australian commercial wheats tended to produce fewer coleoptile tillers of smaller size than overseas germplasm where the coleoptile tiller accounted for up to 12% of total seedling leaf area. This compared favourably with mainstem tiller leaf area, which ranged from 0 to 3.5 cm2 and accounted for up to 16% of plant leaf area. Broad-sense heritabilities were high for coleoptile tiller presence and size in favourable conditions (c. 75%) but low (c. 40%) for seedlings evaluated across nitrogen content-varying soils. Generation means analysis was used to investigate genetic control for coleoptile tiller growth across multiple populations. Significant (P < 0.05) differences were observed among generations for coleoptile tiller frequency and growth (numbers of leaves, leaf area, and biomass). These differences reflected strong additive genetic control with little evidence for any gene action × year interaction. Increases in coleoptile tiller frequency and mass were correlated with larger embryo size and wider seedling leaves to increase seedling leaf area (rg = 0.89). Comparisons between reciprocal F1 and F2 generation means indicated strong maternal effects for coleoptile tiller growth in some but not all crosses. Screening in favourable environments will increase heritability and aid in selection for progenies producing large coleoptile tillers. Evidence for additive genetic control should permit early generation selection but not without some progeny-testing for coleoptile tiller growth together with other early vigour components associated with increased plant leaf area.

A cytological and molecular analysis of D-genome chromosome retention following F2–F6 generations of hexaploid×tetraploid wheat crosses

2018 ◽  
Vol 69 (2) ◽  
pp. 121 ◽  
Author(s):  
Sriram Padmanaban ◽  
Peng Zhang ◽  
Mark W. Sutherland ◽  
Noel L. Knight ◽  
Anke Martin
Keyword(s):  
Durum Wheat ◽  
Tetraploid Wheat ◽  
Triticum Aestivum L ◽  
Food Crops ◽  
Cytological Analysis ◽  
Genome Chromosome ◽  
D Genome ◽  
Ploidy Levels ◽  
F2 Generation ◽  
Global Food

Both hexaploid bread wheat (AABBDD) (Triticum aestivum L.) and tetraploid durum wheat (AABB) (T. turgidum spp. durum) are highly significant global food crops. Crossing these two wheats with different ploidy levels results in pentaploid (AABBD) F1 lines. This study investigated the differences in the retention of D chromosomes between different hexaploid × tetraploid crosses in subsequent generations by using molecular and cytological techniques. Significant differences (P < 0.05) were observed in the retention of D chromosomes in the F2 generation depending on the parents of the original cross. One of the crosses, 2WE25 × 950329, retained at least one copy of each D chromosome in 48% of its F2 lines. For this cross, the retention or elimination of D chromosomes was determined through several subsequent self-fertilised generations. Cytological analysis indicated that D chromosomes were still being eliminated at the F5 generation, suggesting that in some hexaploid × tetraploid crosses, D chromosomes are unstable for many generations. This study provides information on the variation in D chromosome retention in different hexaploid × tetraploid wheat crosses and suggests efficient strategies for utilising D genome retention or elimination to improve bread and durum wheat, respectively.

FACTORIAL GENETIC ANALYSIS OF A TWO-LOCUS SYSTEM IN BARLEY

1973 ◽  
Vol 15 (3) ◽  
pp. 473-482 ◽  
Author(s):  
S. Jana
Keyword(s):  
Dominance Effect ◽  
Early Stage ◽  
Genotypic Variation ◽  
Genetic Effect ◽  
Additive Genetic Effect ◽  
Genetic Studies ◽  
Genetic Method ◽  
Quantitative Genetic ◽  
Single Character ◽  
Locus System

Backcross-derived homozygous lines of Atlas barley, isogenic except for two unlinked loci, A/a and B/b, each with two alleles, were crossed to produce five heterozygous genotypes. The nine possible genotypes were then used for detailed quantitative genetic studies at various stages in the life cycle of the plant. Components of genotypic variation attributable to additive, dominance and epistatic effects of genes were estimated by the use of the factorial genetic method. The relative magnitudes of these components for a single character were found to change considerably with the age of the plant and they also changed from character to character at the same age. Additive genetic effect, particularly of the A/a locus was the largest component of genotypic variation in the first 6 weeks of growth of the seedling. Epistasis was important at the very early stage of growth, but decreased strikingly in size at a time immediately following jointing. In general, the A/a locus was found to be genetically more active than the B/b locus for a number of metrical characters. Dominance effect of the A/a locus was responsible for about 50% of the total gene controlled variability for grain yield.

scholarly journals Genetic control of common bean (Phaseolus vulgaris) resistance to powdery mildew (Erysiphe polygoni)

1999 ◽  
Vol 22 (2) ◽  
pp. 233-236 ◽  
Author(s):  
Viviane Ferreira Rezende ◽  
Magno Antonio Patto Ramalho ◽  
Hercules Renato Corte
Keyword(s):  
Phaseolus Vulgaris ◽  
Powdery Mildew ◽  
Common Bean ◽  
Genetic Control ◽  
Infected Plant ◽  
Statistical Design ◽  
Linear Regression Coefficient ◽  
Simple Lattice ◽  
Erysiphe Polygoni ◽  
F2 Generation

Genetic control of common bean (Phaseolus vulgaris) resistance to powdery mildew (Erysiphe polygoni) was studied using segregating populations from the bean variety crosses Jalo x ESAL 686 and ESAL 550 x ESAL 686. F2 plants, together with the parents, were inoculated and evaluated using a scale of values from one (plant without symptoms) to nine (completely infected plant). F2 plants were harvested individually, and F2:3 families were obtained. These families were evaluated in an 11 x 11 and 12 x 12 simple lattice statistical design for the Jalo x ESAL 686 and ESAL 550 x ESAL 686 crosses, respectively, using the same value scale as the F2 generation. The segregation observed in F2 plants and F2:3 families indicated that two genes are involved in genetic control, due to a double recessive epistasis. The high linear regression coefficient (b) between F2 plants and their F2:3 family, 0.66 for ESAL 550 x ESAL 686 cross, and 0.71 for Jalo x ESAL 686 cross, showed that the trait is highly heritable.

scholarly journals Physiological Differences between Zinc-efficient and Zinc-inefficient Genotypes of Interspecific Exacum

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 571b-571
Author(s):  
Andrew Riseman ◽  
Richard Craig
Keyword(s):  
Zinc Deficiency ◽  
Genotypic Variation ◽  
Weight Ratio ◽  
Genetic Effect ◽  
Dry Weight ◽  
Exchange Capacity ◽  
Zinc Efficiency ◽  
Solution Ph ◽  
Chi Square ◽  
Root Shoot Ratio

Research in Penn State's Exacum breeding program has revealed genotypic variation for the development of zinc deficiency, which may indicate the presence of zinc efficiency factors. Through preliminary experiments, we have identified both genetic families and individual genotypes that can be classified as either zinc-efficient or zinc-inefficient. Chi-square contingency analyses indicate significant differences (P < 0.001) in segregation patterns for zinc deficiency among hybrid families. Segregation patterns within families ranged from 100% of the progeny developing zinc deficiency to 100% of the progeny remaining healthy. Two genotypes contrasting in zinc efficiency have been identified and used in experiments designed to investigate physiological factors related to zinc efficiency. The zinc-efficient genotype has a significantly higher ability to decrease solution pH (P < 0.01), significantly higher root cation exchange capacity (P < 0.007), significantly lower root/shoot ratio (P < 0.001), significantly lower water loss/cm2 leaf (P < 0.03), and significantly higher fresh weight/dry weight ratio (P < 0.001). Research on zinc uptake rates is currently being conducted utilizing the efficient and inefficient genotypes. Based on all of our research, we conclude that 1) a strong genetic effect is involved in the zinc nutritional status of interspecific Exacum hybrids and 2) a number of physiological traits differ between zinc-efficient and zinc-inefficient genotypes.

scholarly journals Drought and Heat Stress Impacts on Phenolic Acids Accumulation in Durum Wheat Cultivars

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2142
Author(s):  
Barbara Laddomada ◽  
Antonio Blanco ◽  
Giovanni Mita ◽  
Leone D’Amico ◽  
Ravi P. Singh ◽  
...  
Keyword(s):  
Heat Stress ◽  
Ferulic Acid ◽  
Durum Wheat ◽  
Phenolic Acids ◽  
Grain Morphology ◽  
Growth Conditions ◽  
Severe Drought ◽  
Wheat Cultivars ◽  
High Accumulation ◽  
Drought And Heat Stress

Droughts and high temperatures are the main abiotic constraints hampering durum wheat production. This study investigated the accumulation of phenolic acids (PAs) in the wholemeal flour of six durum wheat cultivars under drought and heat stress. Phenolic acids were extracted from wholemeals and analysed through HPLC-DAD analysis. Ferulic acid was the most represented PA, varying from 390.1 to 785.6 µg/g dry matter across all cultivars and growth conditions, followed by sinapic acids, p-coumaric, vanillic, syringic, and p-hydroxybenzoic acids. Among the cultivars, Cirno had the highest PAs content, especially under severe drought conditions. Heat stress enhanced the accumulation of minor individual PAs, whereas severe drought increased ferulic acid and total PAs. Broad-sense heritability was low (0.23) for p-coumaric acid but ≥0.69 for all other components. Positive correlations occurred between PA content and grain morphology and between test weight and grain yield. Durum wheat genotypes with good yields and high accumulation of PAs across different growing conditions could be significant for durum wheat resilience and health-promoting value.

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