scholarly journals Genetic Mechanisms Underlying Apimaysin and Maysin Synthesis and Corn Earworm Antibiosis in Maize (Zea mays L.)

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1997-2006
Author(s):  
E A Lee ◽  
P F Byrne ◽  
M D McMullen ◽  
M E Snook ◽  
B R Wiseman ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Larval Growth ◽  
Corn Earworm ◽  
Phenotypic Variance ◽  
Significant Qtls ◽  
F2 Population ◽  
Genetic Mechanisms ◽  
Trait Locus ◽  
Maize Silks ◽  
Related Compounds

Abstract C-glycosyl flavones in maize silks confer resistance (i.e., antibiosis) to corn earworm (Helicoverpa zea [Boddie]) larvae and are distinguished by their B-ring substitutions, with maysin and apimaysin being the di- and monohydroxy B-ring forms, respectively. Herein, we examine the genetic mechanisms underlying the synthesis of maysin and apimaysin and the corresponding effects on corn earworm larval growth. Using an F2 population, we found a quantitative trait locus (QTL), rem1, which accounted for 55.3% of the phenotypic variance for maysin, and a QTL, pr1, which explained 64.7% of the phenotypic variance for apimaysin. The maysin QTL did not affect apimaysin synthesis, and the apimaysin QTL did not affect maysin synthesis, suggesting that the synthesis of these closely related compounds occurs independently. The two QTLs, rem1 and pr1, were involved in a significant epistatic interaction for total flavones, suggesting that a ceiling exists governing the total possible amount of C-glycosyl flavone. The maysin and apimaysin QTLs were significant QTLs for corn earworm antibiosis, accounting for 14.1% (rem1) and 14.7% (pr1) of the phenotypic variation. An additional QTL, represented by umc85 on the short arm of chromosome 6, affected antibiosis (R2 = 15.2%), but did not affect the synthesis of the C-glycosyl flavones.

The genetic basis of C-glycosyl flavone B-ring modification in maize (Zea mays L.) silks

Genome ◽  
2003 ◽  
Vol 46 (2) ◽  
pp. 182-194 ◽  
Author(s):  
Moisés Cortés-Cruz ◽  
Maurice Snook ◽  
Michael D McMullen
Keyword(s):  
Zea Mays ◽  
Chlorogenic Acid ◽  
Helicoverpa Zea ◽  
Zea Mays L ◽  
Corn Earworm ◽  
Chromosome 4 ◽  
Genetic Mechanisms ◽  
Trait Locus ◽  
High Concentrations ◽  
Major Qtl

Resistance to corn earworm (CEW) (Helicoverpa zea Boddie) has been attributed to high concentrations of C-glycosyl flavones and chlorogenic acid in maize (Zea mays L.) silks. The most common C-glycosyl flavones isolated from maize silks are maysin, apimaysin, and methoxymaysin, which are distinguished by their B-ring substitutions. For a better understanding of the genetic mechanisms underlying the synthesis of these compounds, we conducted a quantitative trait locus (QTL) study with two populations: (Tx501 × NC7A)F2 and (Tx501 × Mp708)F2. For chlorogenic acid, maysin, and methoxymaysin concentration, the major QTL for both populations was located on chromosome 4 near umc1963. For apimaysin, the major QTL in both populations was located at the position of the pr1 locus on chromosome 5. The QTL alleles on chromosome 4 that increased the synthesis of methoxymaysin significantly decreased the synthesis of maysin and chlorogenic acid. This decrease in maysin concentration was four-fold greater than the increase in methoxymaysin. Our results indicate that the QTL on chromosome 4, responsible for the increase in methoxymaysin synthesis, alters the dynamics of both the phenylpropanoid and flavonoid pathways.Key words: pr1, flavonoid 3'-hydroxylase, maysin, apimaysin, methoxymaysin.

Influence of Transgenic Corn Expressing Insecticidal Protein of Bacillus thuringiensis Berliner on Natural Populations of Corn Earworm (Lepidoptera: Noctuidae) and Southwestern Corn Borer (Lepidoptera: Crambidae)

2006 ◽  
Vol 41 (3) ◽  
pp. 221-231 ◽  
Author(s):  
Kerry C. Allen ◽  
Henry N. Pitre
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Larval Growth ◽  
Natural Populations ◽  
Corn Earworm ◽  
Bt Corn ◽  
Transgenic Corn ◽  
Diatraea Grandiosella ◽  
Corn Hybrids ◽  
Corn Borer

A 2-yr study was conducted to measure the influence of transgenic corn, Zea mays L., expressing the CrylAb endotoxin of Bacillus thuringiensis (Berliner) (Bt) by means of Event MON810 on natural populations of Helicoverpa zea (Boddie) and Diatraea grandiosella (Dyar). The studies were conducted at Leland and Morgan City, MS, in 1999 and at Morgan City in 2000. Although total numbers of H. zea larvae were not significantly different on transgenic corn hybrids compared with their near-isogenic parent lines, fewer large larvae were found on the transgenic hybrids. Differences in H. zea larval growth were noticeable when larvae fed on Bt corn vs non-Bt corn. The delay in larval growth for insects within a single generation, which could possibly result in asynchronous mating between insecticide resistant and susceptible insects, was observed for larvae feeding on plants expressing the Bt toxin. Diatraea grandiosella caused limited damage to the transgenic corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with the near-isogenic, non-Bt corn parents; however, there was a trend toward higher yields for Bt hybrids compared with their near-isogenic non-Bt parents.

Quantitative genetic analysis of flowering time in tomato

Genome ◽  
2007 ◽  
Vol 50 (3) ◽  
pp. 303-315 ◽  
Author(s):  
José M. Jiménez-Gómez ◽  
Carlos Alonso-Blanco ◽  
Alicia Borja ◽  
Germán Anastasio ◽  
Trinidad Angosto ◽  
...  
Keyword(s):  
Flowering Time ◽  
Solanum Species ◽  
Day Length ◽  
Leaf Number ◽  
Phenotypic Variance ◽  
Days To Flowering ◽  
Solanum Lycopersicum L ◽  
Close Relationship ◽  
Genetic Mechanisms ◽  
Trait Locus

Artificial selection of cultivated tomato ( Solanum lycopersicum L.) has resulted in the generation of early-flowering, day-length-insensitive cultivars, despite its close relationship to other Solanum species that need more time and specific photoperiods to flower. To investigate the genetic mechanisms controlling flowering time in tomato and related species, we performed a quantitative trait locus (QTL) analysis for flowering time in an F2 mapping population derived from S. lycopersicum and its late-flowering wild relative S. chmielewskii . Flowering time was scored as the number of days from sowing to the opening of the first flower (days to flowering), and as the number of leaves under the first inflorescence (leaf number). QTL analyses detected 2 QTLs affecting days to flowering, which explained 55.3% of the total phenotypic variance, and 6 QTLs for leaf number, accounting for 66.7% of the corresponding phenotypic variance. Four of the leaf number QTLs had not previously been detected for this trait in tomato. Colocation of some QTLs with flowering-time genes included in the genetic map suggests PHYB2, FALSIFLORA, and a tomato FLC-like sequence as candidate genes that might have been targets of selection during the domestication of tomato.

Effect of Cuticular Lipids From Silks of Selected Corn Genotypes on the Development of Corn Earworm Larvae

1994 ◽  
Vol 29 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Guang Yang ◽  
B. R. Wiseman ◽  
Karl E. Espelie
Keyword(s):  
Helicoverpa Zea ◽  
Zea Mays L ◽  
Control Diet ◽  
Larval Growth ◽  
Adult Emergence ◽  
Corn Earworm ◽  
Cuticular Lipids ◽  
Cuticular Lipid ◽  
Corn Silk ◽  
Meridic Diet

Eleven genotypes of corn, Zea mays L., known to vary in their resistance to silk-feeding by larvae of the corn earworm, Helicoverpa zea (Boddie), were used to study the effect of corn silk cuticular lipids on larval growth and development. Growth of the corn earworm was significantly enhanced when larvae were reared on meridic diet containing corn silks from which the cuticular lipids had been removed. Growth of larvae reared on a diet containing unextracted silks from genotypes ‘Stowell's’ ‘Evergreen’, ‘Pioneer 3369A’, and ‘PI340856’ was not affected. When the cuticular lipid extracts of corn silks were added to a meridic diet, no significant differences were found in the weight of 8-day larvae, time to pupation, or days to adult emergence for larvae reared on silks of several corn genotypes. However, the weight of pupae was significantly less when larvae were fed a diet containing cuticular lipids extracted from silks of three corn genotypes ‘Stowell's Evergreen’, ‘GE37’, and ‘Zapalote Chico 2451#(P)C3’ than the weight of pupae from larvae that fed on the control diet.

Stadia, Larval-Pupal Weight, and Width of Head Capsules of Corn Earworm (Lepidoptera: Noctuidae) After Feeding on Varying Resistance Levels of Maize Silks

1991 ◽  
Vol 26 (3) ◽  
pp. 303-309
Author(s):  
B. R. Wiseman ◽  
D. J. Isenhour ◽  
V. R. Bhagwat
Keyword(s):  
Helicoverpa Zea ◽  
Zea Mays L ◽  
Head Capsule ◽  
Developmental Time ◽  
Corn Earworm ◽  
Pupal Weight ◽  
Susceptible Genotype ◽  
Resistant Material ◽  
Maize Silks ◽  
Lepidoptera Noctuidae

Weight of larvae, developmental time to pupation, weight of pupae, length of stadia, and width of head capsule were determined for larvae of the corn earworm, Helicoverpa zea (Boddie), that were fed on meridic diets with silks of ‘Stowell's Evergreen’, a susceptible genotype, or low, intermediate, and high levels of ‘Zapalote Chico’, a corn, Zea mays L., cultivar with antibiotic resistance. As the level of resistance increased, the weight of larvae at 9 days and weight of pupae significantly decreased, and developmental time to pupation significantly increased. Also, as the concentration of resistant material increased in the diet, stadial length also significantly increased. The intermediate and high levels of resistance also resulted in a significant reduction in the width of the head capsule of larvae. Thus, two new characteristics of resistance in maize silks to the corn earworm were identified: increased stadia and decreased width of head capsule.

scholarly journals Inferring Linkage Disequilibrium Between a Polymorphic Marker Locus and a Trait Locus in Natural Populations

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 457-467 ◽  
Author(s):  
Z W Luo ◽  
S H Tao ◽  
Z-B Zeng
Keyword(s):  
Linkage Disequilibrium ◽  
Allele Frequency ◽  
Random Mating ◽  
Natural Populations ◽  
Polymorphic Marker ◽  
Marker Locus ◽  
Model Parameters ◽  
Phenotypic Variance ◽  
Wide Range ◽  
Trait Locus

Abstract Three approaches are proposed in this study for detecting or estimating linkage disequilibrium between a polymorphic marker locus and a locus affecting quantitative genetic variation using the sample from random mating populations. It is shown that the disequilibrium over a wide range of circumstances may be detected with a power of 80% by using phenotypic records and marker genotypes of a few hundred individuals. Comparison of ANOVA and regression methods in this article to the transmission disequilibrium test (TDT) shows that, given the genetic variance explained by the trait locus, the power of TDT depends on the trait allele frequency, whereas the power of ANOVA and regression analyses is relatively independent from the allelic frequency. The TDT method is more powerful when the trait allele frequency is low, but much less powerful when it is high. The likelihood analysis provides reliable estimation of the model parameters when the QTL variance is at least 10% of the phenotypic variance and the sample size of a few hundred is used. Potential use of these estimates in mapping the trait locus is also discussed.

scholarly journals Linkage mapping identifies a non-synonymous mutation in FLOWERING LOCUS T (FT-B1) increasing spikelet number per spike

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Brassac ◽  
Quddoos H. Muqaddasi ◽  
Jörg Plieske ◽  
Martin W. Ganal ◽  
Marion S. Röder
Keyword(s):  
Flowering Time ◽  
Aspartic Acid ◽  
Synonymous Substitution ◽  
Minor Effect ◽  
Phenotypic Variance ◽  
Spikelet Number ◽  
Wheat Varieties ◽  
Trait Locus ◽  
A Minor ◽  
Spikelet Number Per Spike

AbstractTotal spikelet number per spike (TSN) is a major component of spike architecture in wheat (Triticumaestivum L.). A major and consistent quantitative trait locus (QTL) was discovered for TSN in a doubled haploid spring wheat population grown in the field over 4 years. The QTL on chromosome 7B explained up to 20.5% of phenotypic variance. In its physical interval (7B: 6.37–21.67 Mb), the gene FLOWERINGLOCUST (FT-B1) emerged as candidate for the observed effect. In one of the parental lines, FT-B1 carried a non-synonymous substitution on position 19 of the coding sequence. This mutation modifying an aspartic acid (D) into a histidine (H) occurred in a highly conserved position. The mutation was observed with a frequency of ca. 68% in a set of 135 hexaploid wheat varieties and landraces, while it was not found in other plant species. FT-B1 only showed a minor effect on heading and flowering time (FT) which were dominated by a major QTL on chromosome 5A caused by segregation of the vernalization gene VRN-A1. Individuals carrying the FT-B1 allele with amino acid histidine had, on average, a higher number of spikelets (15.1) than individuals with the aspartic acid allele (14.3) independent of their VRN-A1 allele. We show that the effect of TSN is not mainly related to flowering time; however, the duration of pre-anthesis phases may play a major role.

Rapid identification of a stripe rust resistance gene YrXK in Chinese wheat line Xike01015 using specific locus amplified fragment (SLAF) sequencing

Plant Disease ◽  
2021 ◽  
Author(s):  
Cai Sun ◽  
Yike Liu ◽  
Qiang Li ◽  
Baotong Wang ◽  
Shuhui Chen ◽  
...  
Keyword(s):  
Stripe Rust ◽  
Puccinia Striiformis ◽  
Gene Annotation ◽  
Dominant Gene ◽  
Rapid Identification ◽  
Wheat Breeding ◽  
Stripe Rust Resistance ◽  
Phenotypic Variance ◽  
F2 Population ◽  
Chinese Wheat

Wheat stripe rust, an airborne fungal disease and caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is one of the most devastating diseases on wheat. It is the most effective and economical measure for the diseases control to identify high-level resistance genes and apply in wheat breeding. Chinese wheat cultivar Xike01015 presents high levels of all stage resistance (ASR) to the current predominant Pst race CYR33. In this study, a single dominant gene, designated as YrXk, was identified in Xike01015 conferring resistance to CYR33 with genetic analysis of F2 and BC1 population from cross of Mingxian169 (susceptible) and Xike01015. The specific length amplified fragment sequencing (SLAF-seq) strategy was used to construct linkage map in the F2 population. QTL analysis mapped YrXk to a 12.4 Mb segment on chromosome1BS, explaining over 86.96% phenotypic variance. Gene annotation in the QTL region identified three differential expressed candidate genes , TraesCS1B02G168600.1, TraesCS1B02G170200.1, and TraesCS1B02G172400.1. The qRT-PCR results displayed that TraesCS1B02G170200.1 and TraesCS1B02G168600.1 significantly up-regulated and down-regulated, respectively, and TraesCS1B02G170200.1 slightly up-regulated after changed with CYR33 in the seedling stage, which indicating these genes may function in wheat resistance to stripe rust. The results of this study can be used in wheat breeding for improving resistance to stripe rust.

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