scholarly journals Genetic resistance of Eucalyptus globulus to autumn gum moth defoliation and the role of cuticular waxes

2002 ◽  
Vol 32 (11) ◽  
pp. 1961-1969 ◽  
Author(s):  
T H Jones ◽  
B M Potts ◽  
R E Vaillancourt ◽  
N W Davies
Keyword(s):  
Genetic Variation ◽  
Eucalyptus Globulus ◽  
Field Trial ◽  
Genetic Resistance ◽  
Cuticular Wax ◽  
Wax Esters ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Cuticular Waxes

This study investigated the association between resistance of Eucalyptus globulus Labill. to autumn gum moth (Mnesempala privata Guenée) defoliation and cuticular wax compounds. In a field trial consisting of clonally replicated F2 families of E. globulus, situated in Tasmania, Australia, significant genetic variation in resistance was detected in two of three F2 families. The broad-sense heritability for defoliation within families ranged from 0.24 to 0.33. The 15 most resistant and the 15 most susceptible genotypes within each variable family were compared for their relative levels of 26 cuticular wax compounds. While no significant correlation between resistance and total wax yield estimates was found, significant differences were detected between resistant and susceptible classes in the relative quantities of several aliphatic phenylethyl and benzyl wax esters within both families. This association does not appear to be a response induced by defoliation. The broad-sense heritabilities of the variation in these compounds were high (0.82–0.94). Our findings suggest that these wax compounds are a mechanism of genetic resistance to autumn gum moth in E. globulus.

scholarly journals Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis

2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Cold Acclimation ◽  
Water Loss ◽  
Cuticular Wax ◽  
Dehydration Stress ◽  
Wax Deposition ◽  
Cuticular Waxes ◽  
Gas Chromatography Mass Spectroscopy

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.

scholarly journals Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones

2004 ◽  
Vol 34 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Marcelo Renato Alves de Araújo ◽  
Bruce Coulman
Keyword(s):  
Genetic Variation ◽  
Crude Protein ◽  
Genetic Correlations ◽  
Neutral Detergent Fiber ◽  
Broad Sense ◽  
Grass Species ◽  
Broad Sense Heritability ◽  
Bromus Riparius ◽  
Heritability Estimates ◽  
Meadow Bromegrass

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

scholarly journals Variance Components and Estimates of Broad-sense Heritability of Nut and Kernel Traits in Hazelnut

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 494D-494
Author(s):  
Qiang Yao ◽  
Shawn A. Mehlenbacher
Keyword(s):  
Genetic Variation ◽  
Phenotypic Variation ◽  
Variance Components ◽  
Genetic Basis ◽  
Corylus Avellana ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Narrow Sense ◽  
High Heritability ◽  
Kernel Traits

Seventy-seven trees representing 41 hazelnut (Corylus avellana L.) genotypes were to evaluate variance components and broad-sense heritability for 10 nut and kernel traits from 1994 to 1996. All effects in the models were assumed to be random. All traits had extremely high heritability. This indicated that nearly all of the phenotypic variation had a genetic basis. Knowledge of variance components may help us efficiently allocate resources. Broad-sense heritability estimates were larger than those in narrow sense, suggesting the presence of nonadditive genetic variation in the population.

scholarly journals Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis

2020 ◽  
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Cold Acclimation ◽  
Water Loss ◽  
Cuticular Wax ◽  
Dehydration Stress ◽  
Wax Deposition ◽  
Cuticular Waxes ◽  
Leaf Water Loss

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing non-stomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss; while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. GC-MS analysis identified a characteristic decrease in the accumulation of certain waxes (e.g. alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. FTIR spectroscopy also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress, and are promising genetic targets of interest.

scholarly journals Heritability of Cortisol Production and Metabolism Throughout Adolescence

2019 ◽  
Vol 105 (2) ◽  
pp. 443-452 ◽  
Author(s):  
Britt J van Keulen ◽  
Conor V Dolan ◽  
Ruth Andrew ◽  
Brian R Walker ◽  
Hilleke E Hulshoff Pol ◽  
...  
Keyword(s):  
Individual Differences ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Environmental Influences ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Total Contribution ◽  
Cortisol Metabolism ◽  
Genetic And Environmental Factors

Abstract Context Inter-individual differences in cortisol production and metabolism emerge with age and may be explained by genetic factors. Objective To estimate the relative contributions of genetic and environmental factors to inter-individual differences in cortisol production and metabolism throughout adolescence. Design Prospective follow-up study of twins. Setting Nationwide register. Participants 218 mono- and dizygotic twins (N = 109 pairs) born between 1995 amd 1996, recruited from the Netherlands Twin Register. Cortisol metabolites were determined in 213, 169, and 160 urine samples at the ages of 9, 12, and 17, respectively. Main outcome measures The total contribution of genetic factors (broad-sense heritability) and shared and unshared environmental influences to inter-individual differences in cortisol production and activities of 5α-reductase, 5β-reductase, and 11β-hydroxysteroid dehydrogenases and cytochrome P450 3A4. Results For cortisol production rate at the ages of 9, 12, and 17, broad-sense heritability was estimated as 42%, 30%, and 0%, respectively, and the remainder of the variance was explained by unshared environmental factors. For cortisol metabolism indices, the following heritability was observed: for the A-ring reductases (5α-and 5β-reductases), broad-sense heritability increased with age (to >50%), while for the other indices (renal 11β-HSD2, global 11β-HSD, and CYP3A4), the contribution of genetic factors was highest (68%, 18%, and 67%, respectively) at age 12. Conclusions The contribution of genetic factors to inter-individual differences in cortisol production decreased between 12 and 17y, indicative of a predominant role of individual circumstances. For cortisol metabolism, distinct patterns of genetic and environmental influences were observed, with heritability that either increased with age or peaked at age 12y.

Composition of Epicuticular Waxes from Fruits of Jojoba (Simmondsia chinensis [Link] Schneider)

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1053-1056 ◽  
Author(s):  
Paul-Gerhard Gülz
Keyword(s):  
Homologous Series ◽  
Cuticular Wax ◽  
Wax Esters ◽  
Hydrocarbon Fraction ◽  
Simmondsia Chinensis ◽  
Epicuticular Waxes ◽  
Cuticular Waxes ◽  
Branched Alkanes ◽  
Seed Coats ◽  
Long Chain

Abstract Epicuticular waxes were extracted with hexane from dry Jojoba pericarp and seed. These cuticular waxes consisted of hydrocarbons, wax esters, free acids, free alcohols and sterols; additionally aldehydes were found in the wax obtained from seed coats. The hydrocarbon fraction contained a homologous series of n-alkanes and branched alkanes but no alkenes. The composition of the wax esters of the cuticular wax was similar to that of the cotyledons. The esters are composed of monounsaturated long chain acids and alcohols.

Genetic variation in juvenile growth of tamarack (Larixlaricina) in northwestern Ontario

1993 ◽  
Vol 23 (9) ◽  
pp. 1852-1862 ◽  
Author(s):  
Robert E. Farmer Jr. ◽  
Gwenoth O'Reilly ◽  
Deng Shaotang
Keyword(s):  
Genetic Variation ◽  
Common Garden ◽  
Shoot Elongation ◽  
Allozyme Variation ◽  
Broad Sense ◽  
Population Variation ◽  
Broad Sense Heritability ◽  
Northwestern Ontario ◽  
Test Population ◽  
N 93

Nested designs incorporating provenances and families and clones within provenances were used in two common garden tests near Thunder Bay, Ont. (48°N, 84°W) to evaluate genetic variation in growth and sylleptic branching among and within populations of tamarack (Larixlaricina (Du Roi) K. Koch) from 46°N, 80°W to 53°N, 93°W. At 7 and 8 years there was a north-south trend of increasing height among provenances. Genetic variation in height was related to both rate and duration of shoot elongation, but latitudinal variation in shoot growth mainly resulted from differences in late-season elongation. There was substantial genetic variance in height within populations, and broad-sense heritability based on pooled variances was 0.23 for one test population at 8 years and 0.11 for the second at 7 years. The more vigorous southern provenances had a greater potential for sylleptic branching in the test area than northern sources, and wide within-population variation in syllepsis was under stronger genetic control than growth (broad-sense heritability = 0.47 in year 6). Patterns of genetic variation observed in the study were not congruent with patterns of morphological and allozyme variation previously reported for the sampled populations.

Understanding the Role of Populus ECERIFERUM2-Likes in the Biosynthesis of Very-Long-Chain Fatty Acids for Cuticular Waxes

2021 ◽  
Author(s):  
Eliana Gonzales-Vigil ◽  
Michelle E vonLoessl ◽  
Jeff Y Chen ◽  
Sitong Li ◽  
Tegan M Haslam ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Populus Trichocarpa ◽  
Cuticular Wax ◽  
Cuticular Waxes ◽  
Elongation Complex ◽  
Glucuronidase Reporter ◽  
Chain Lengths ◽  
Long Chain ◽  
Condensing Enzyme

Abstract Cuticular waxes are derived from very-long-chain fatty acid (VLCFA) precursors made by the concerted action of four enzymes that form the fatty acid (FA) elongation complex. The condensing enzyme of the complex confers specificity to substrates of different chain lengths, yet on its own cannot account for the biosynthesis of VLCFAs longer than 28 carbons (C28). Recent evidence from Arabidopsis thaliana points to a synergistic role of clade II BAHD acyltransferases and condensing enzymes in the elongation of VLCFAs beyond C28. In Populus trichocarpa, clade II is composed of seven uncharacterized paralogous genes (PtCER2-like1–7). In the present study, five of these genes were heterologously expressed in yeast and their respective FA profiles were determined. PtCER2-likes differentially altered the accumulation of C28 and C30 FAs when expressed in the presence of the condensing enzyme AtCER6. Among these, PtCER2-like5 produced the highest levels of C28 FAs in yeast and its expression was localized to the epidermis in β-glucuronidase-reporter poplar lines, consistent with a role in cuticular wax biosynthesis. Complementation of the A. thaliana cer2-5 mutant with PtCER2-like5 increased the levels of C28-derived cuticular waxes at the expense of C30-derived components. Together, these results demonstrate that the role of CER2-likes in cuticular wax biosynthesis is conserved in Populus clade II BAHD acyltransferases.

scholarly journals Role of Some Genetic Parameters on Breeding Work for Resistance to Pre-Harvest

2012 ◽  
Vol 69 (1) ◽  
Author(s):  
Lupu Nicolae ◽  
Vasile Moldovan ◽  
Rozalia Kadar ◽  
Ionut Racz
Keyword(s):  
Genetic Parameters ◽  
Phenotypic Expression ◽  
Broad Sense ◽  
Quantitative Character ◽  
Broad Sense Heritability ◽  
Narrow Sense ◽  
Falling Number ◽  
Narrow Sense Heritability ◽  
Gene Effects

For wheat ( Triticum aestivum ), periods of prolonged rainfall and high humidity after the grain has ripened and before it can be harvested can contribute to, so called pre-harvest sprouting (PHS), which can be considered as a premature germination. PHS can be defined a complex quantitative character having two important components: sprouting score and falling number. The two these components are controlled by gene effects which are predominant of additive nature. Our research have been conducted on parental, F 1, F2, backcross generations means, from 4 cyclic crosses with common parents differing in their reaction to PHS and falling number. Broad sense heritability coefficients for PHS score showed high values in the case of majority hybrids that indicate the important role of genotype in phenotypic expression of reaction to sprouting. Concerning to falling number, broad sense heritability coefficients had smaller values. For wheat as a self pollinated crop, is preferable to be used narrow sense heritability which reflects additive genetic contribution to phenotypic expression of sprouting or falling number, because only additive gene effects can be fixed to progeny. When PHS score, or falling number have high values for narrow sense heritability (higher 50), is recommended the beginning of selection in F 2 and in these cases can be successful applied pedigree selection. Concluding, high heritabilities associated with other genetic parameters can be important tools at hand of breeders. They indicated that wheat selection for PHS tolerance or falling number would be effective in populations involving crosses of sensitive and tolerant parents.

scholarly journals Cuticular Wax Composition of Coconut Palms and their Susceptibility to Lethal Yellowing Disease

2017 ◽  
Vol 56 (1) ◽  
Author(s):  
Gabriela A. Arroyo-Serralta ◽  
Daniel Zizumbo-Villareal ◽  
Fabiola Escalante Erosa ◽  
Luis M. Peña- Rodríguez
Keyword(s):  
Chromatographic Analysis ◽  
Cuticular Wax ◽  
Cuticular Waxes ◽  
Lethal Yellowing Disease ◽  
Lethal Yellowing ◽  
Yellowing Disease ◽  
Main Components ◽  
The Individual ◽  
Plant Pathogen Interactions

A number of metabolites isolated and identified from cuticular waxes have been used as chemotaxonomical markers and to explain the role of the wax layer in plant-insect and plant-pathogen interactions. Chromatographic analysis of the cuticular wax from pinnae of five coconut palm ecotypes showed that the three main components (<strong>I</strong>, <strong>II</strong>, <strong>III</strong>) in the wax can be used as chemotaxonomical markers for classification. The positive correlation found between the content of metabolites <strong>I</strong>, <strong>II</strong>, and <strong>III</strong> in the wax from the various ecotypes and their resistance or susceptibility to the lethal yellowing disease of coconut palms, did not coincide with the results obtained in an antifeedant assay. The results suggest that while the individual components do not play a significant role in the palm-insect interaction, the full composition of the cuticular wax does.

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