scholarly journals Inheritance of Resistance to Phaeosphaeria Leaf Spot of Maize

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 798-800 ◽  
Author(s):  
M. L. Carson
Keyword(s):  
Leaf Spot ◽  
Gene Action ◽  
Inbred Lines ◽  
Gene Interactions ◽  
Inheritance Of Resistance ◽  
Generation Mean Analysis ◽  
Kernel Development ◽  
Effective Factors ◽  
Southern Florida ◽  
Winter Breeding

Phaeosphaeria leaf spot is a potentially important maize disease that has recently appeared in the continental United States in winter breeding nurseries in southern Florida. Inbred lines re lated to B73 are particularly susceptible to Phaeosphaeria leaf spot, whereas inbreds related to Mo17 are highly resistant. The inheritance of resistance to Phaeosphaeria leaf spot was studied in the parents, F1, F2, and backcross generations derived from the cross B73 × Mo17. A replicated experiment was conducted over two winter nursery seasons in a southern Florida nursery Individual plants in plots were evaluated for Phaeosphaeria leaf spot severity (0 to 9 scale) at the mid-dent stage of kernel development. Variation in segregating generations appeared continuous, so generation mean analysis was used. Additive and, to a lesser extent, dominance gene action were determined to play a role in the inheritance of reaction to Phaeosphaeria leaf spot There was no evidence for epistatic gene interactions. Heritabilities (both narrow and broad sense) were high (0.70 to 0.85) and the magnitude of genotype × environment interactions was low. Estimates of the number of effective factors (genes) involved in the inheritance of resistance ranged from three to four. Selection should be highly effective in developing inbred lines with adequate levels of resistance to Phaeosphaeria leaf spot.

scholarly journals Inheritance of Resistance to Gray Leaf Spot in Crosses Involving Selected Resistant Inbred Lines of Corn

1998 ◽  
Vol 88 (9) ◽  
pp. 972-982 ◽  
Author(s):  
S. T. Coates ◽  
D. G. White
Keyword(s):  
Leaf Area ◽  
Leaf Spot ◽  
Inbred Lines ◽  
Gray Leaf Spot ◽  
Inheritance Of Resistance ◽  
Generation Mean Analysis ◽  
Susceptible Parent ◽  
Dominance Model ◽  
Resistant Parent ◽  
Naturally Occurring

Three populations derived from crosses of selected resistant inbreds (061, B37HtN, and DS:74:1071) with susceptible inbred FR1141 and a population derived from a cross of B37 × B37HtN were evaluated for gray leaf spot severity in 1992 and 1993 at Urbana, IL, and Andrews, NC. Populations included the susceptible parent (P1), the resistant parent (P2), F1 and F2 generations, backcrosses BCP1 and BCP2, and, when space and seed were available, one or more of the F3, BCP1S1, and BCP2S1 generations. Plants at Urbana were inoculated, and naturally occurring disease was relied upon at Andrews. Individual plants were rated by visually estimating the percent leaf area blighted (necrotic). Generation mean analysis of data combined over years or locations indicated that a simple additive-dominance model was able to explain the inheritance of resistance for all populations. Dominance effects were detected in all population evaluated. For the FR1141 × 061 and FR1141 × B37HtN populations, dominance was significant at early ratings, but not at late ratings. Results from generation mean analysis for individual years, locations, and rating were variable.

scholarly journals Quantitative Trait Loci Conditioning Resistance to Phaeosphaeria Leaf Spot of Maize Caused by Phaeosphaeria maydis

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 571-574 ◽  
Author(s):  
M.L. Carson ◽  
C.W. Stuber ◽  
M.L. Senior
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Leaf Spot ◽  
Inbred Lines ◽  
Inheritance Of Resistance ◽  
Additive Interaction ◽  
Trait Loci ◽  
The Cross ◽  
Southern Florida ◽  
Ri Lines

Phaeosphaeria leaf spot (PLS) is a potentially important disease of maize (Zea mays) that has appeared in winter breeding nurseries in southern Florida. Inbred lines related to B73 are particularly susceptible to Phaeosphaeria leaf spot, whereas inbreds related to Mo17 are highly resistant. A previous study of the inheritance of resistance to Phaeosphaeria leaf spot in the cross B73 × Mo17 found that resistance is highly heritable and controlled by mostly additive gene action at three or four loci. In this study, we used 158 recombinant inbred (RI) lines derived from the cross B73 × Mo17 to map quantitative trait loci (QTL) governing resistance. The RI lines along with the parent inbred lines and the F1 were evaluated for PLS resistance in replicated trials over two winter growing seasons in southern Florida. Using the composite interval mapping (CIM) function of PLABQTL software, five QTL on four different chromosomes were found to control PLS resistance in Mo17. In addition, the × additive interaction between two of these QTL was found to be significant. Our results are in close agreement with the previous study, where generation mean analysis was used to study the inheritance of resistance to PLS.

scholarly journals Vulnerability of U.S. Maize Germ Plasm to Phaeosphaeria Leaf Spot

Plant Disease ◽  
1999 ◽  
Vol 83 (5) ◽  
pp. 462-464 ◽  
Author(s):  
M. L. Carson
Keyword(s):  
Leaf Spot ◽  
Inbred Lines ◽  
Hybrid Seed Production ◽  
Maize Crop ◽  
Public And Private ◽  
Maize Production ◽  
Seed Industry ◽  
Parental Inbred ◽  
Southern Florida ◽  
The U.S

Phaeosphaeria leaf spot (PLS) is a potentially important maize disease that has recently appeared in the continental United States in winter breeding nurseries in southern Florida. To better predict the potential of this newly introduced disease to inflict damage on the U.S. maize crop, 64 public and private inbred lines and 80 proprietary commercial maize hybrids representing the genetic diversity in the U.S. maize crop were evaluated for resistance to PLS in the 1996-97 and 1997-98 winter nursery seasons. Plots were evaluated for PLS severity (0 to 9 scale) at the early to mid dent stages of kernel development. Relatively few hybrids or inbreds were free from PLS at this growth stage. Inbred lines related to B73 were particularly susceptible to PLS. Relatively few commercial hybrids were as severely diseased as a susceptible check hybrid, indicating that U.S. maize production is not particularly vulnerable to damage from PLS at this time. However, the susceptibility of several widely used parental inbred lines makes PLS a potential concern to the seed industry should it become established in areas of hybrid seed production.

scholarly journals Inheritance of Resistance to Aflatoxin Production in the Cross Between Corn Inbreds B73 and LB31

1997 ◽  
Vol 87 (11) ◽  
pp. 1144-1147 ◽  
Author(s):  
K. W. Campbell ◽  
A. M. Hamblin ◽  
D. G. White
Keyword(s):  
Gene Action ◽  
Dominant Gene ◽  
Aflatoxin Production ◽  
Inheritance Of Resistance ◽  
Generation Mean Analysis ◽  
Additive Variance ◽  
Resistant Parent ◽  
Frequency Distributions ◽  
Selection For ◽  
The Cross

The inheritance of resistance to aflatoxin production in corn (Zea mays) caused by the fungus Aspergillus flavus was studied following inoculation in progeny derived from the cross between the susceptible inbred B73 and the resistant inbred LB31. In 1993, the susceptible parent B73 (P1), resistant parent LB31 (P2), F1, F3, and BCP1-selfed generations were evaluated. In 1994, the study was expanded to include the F2, BCP1, and BCP2 generations. Aflatoxin concentrations were higher in 1993 than 1994. Generation mean analysis showed that additive and dominant gene action were important for resistance to aflatoxin production. Potence ratios indicated dominance for resistance in both years. In 1993, aflatoxin values of the F1 generation were significantly lower than the calculated mid-parent values, indicating dominant gene action favoring resistance. In 1994, values of the F1 generation were not significantly lower than the calculated midparent value. The frequency distributions of aflatoxin values for families of the F3 and BCP1-selfed generations were skewed toward the resistant parent, also indicating dominance. Heritability based on a progeny mean basis of F3 families representing the additive variance plus one-fourth of the dominance variance was estimated at 66% over both years combined. Based on these results, selection for resistance to aflatoxin production in progeny derived from the cross between B73 and LB31 should be effective.

scholarly journals RIL-StEp: epistasis analysis of rice recombinant inbred lines (RILs) reveals candidate interacting genes that control seed hull color and leaf chlorophyll content

2021 ◽  
Author(s):  
Toshiyuki Sakai ◽  
Akira Abe ◽  
Motoki Shimizu ◽  
Ryohei Terauchi
Keyword(s):  
Chlorophyll Content ◽  
Recombinant Inbred ◽  
Complex Traits ◽  
Genetic Architecture ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Gene Interactions ◽  
Leaf Chlorophyll Content ◽  
Leaf Chlorophyll ◽  
Seed Hull

Abstract Characterizing epistatic gene interactions is fundamental for understanding the genetic architecture of complex traits. However, due to the large number of potential gene combinations, detecting epistatic gene interactions is computationally demanding. A simple, easy-to-perform method for sensitive detection of epistasis is required. Due to their homozygous nature, use of recombinant inbred lines (RILs) excludes the dominance effect of alleles and interactions involving heterozygous genotypes, thereby allowing detection of epistasis in a simple and interpretable model. Here, we present an approach called RIL-StEp (recombinant inbred lines stepwise epistasis detection) to detect epistasis using single nucleotide polymorphisms in the genome. We applied the method to reveal epistasis affecting rice (Oryza sativa) seed hull color and leaf chlorophyll content and successfully identified pairs of genomic regions that presumably control these phenotypes. This method has the potential to improve our understanding of the genetic architecture of various traits of crops and other organisms.

Genetics of Cercospora Leaf Spot Resistance in Mungbean [Vigna radiata (L.) Wilczek] through Generation Mean Analysis

2021 ◽  
Author(s):  
Priyanka Choudhary ◽  
Ramesh Chand ◽  
Anil Kumar Singh
Keyword(s):  
Latent Period ◽  
Leaf Spot ◽  
Vigna Radiata ◽  
Generation Mean Analysis ◽  
Cercospora Leaf Spot ◽  
Progress Curve ◽  
High Heritability ◽  
Efficient Breeding ◽  
Important Disease ◽  
Selection Of

Background: Cercospora leaf spot (CLS) is a fungal disease of mungbean [Vigna radiata (L.) Wilczek] caused by Cercospora canescens and now emerged as an important biotic stress. A better understanding of the genetics of CLS resistance will help in formulating efficient breeding procedures in mungbean.Methods: The present investigation focused on genetics of CLS resistance through generation mean analysis (six parameter model) in two intra-specific mungbean crosses namely, Kopergaon × HUM12 and Kopergaon × ML1720. Four quantitative disease resistance components, viz., Area under disease progress curve (AUDPC), Incubation period (IP), Latent period (LP) and degree of sporulation (SP) were studied.Result: A high correlation of AUDPC with latent period (r = –0.68 to –0.79, P less than 0.0001) and SP (r = 0.72 to -0.81, P less than 0.0001) advocated that both are main contributor for CLS disease development. High heterosis along with high heritability in terms of AUDPC ( greater than 0.09) indicated the importance of genetic factor(s) in controlling CLS resistance. Generation mean analysis of both the crosses revealed duplicate epistatic interaction and involvement of two genes for CLS resistance in terms of AUDPC. This study supports oligogenic nature of inheritance, advocating AUDPC along with IP, LP and SP as important disease indicator for selection of CLS resistance in mungbean.

scholarly journals DYNAMICS OF HERITABILITY IN DIFFERENT CHARACTERS OF LETTUCE

2021 ◽  
Vol 34 (3) ◽  
pp. 514-526
Author(s):  
ALISSON HENRIQUE GAMA DE OLIVEIRA ◽  
GABRIEL MASCARENHAS MACIEL ◽  
ANA CAROLINA SILVA SIQUIEROLI ◽  
JOSÉ MAGNO QUEIROZ LUZ ◽  
ERNANI CLARETE DA SILVA
Keyword(s):  
Chlorophyll Content ◽  
Gene Action ◽  
Gene Interactions ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Dominant Type ◽  
Partial Dominance ◽  
Number Of Genes ◽  
Number Of Leaves

ABSTRACT The lack of knowledge of the genetic parameters and the type of gene action results in difficulties to obtain varieties that combine agronomic and functional characteristics. The objective of this study was to determine the type of gene action associated with the contents of chlorophyll and agronomic characteristics in lettuce populations. The research was conducted at the Experimental Station of Vegetables, Monte Carmelo, Brazil. To perform the crosses and obtain the generations P1, P2, F1, F2, Bc1 and Bc2 the genotypes UFU-Albina#2, UFU-Albina#3, UFU-Lisa124#2#1, UFU-Crespa199#1#1 and UFU-Lisa217#5#2 were used as parents. The generations were evaluated for three characteristics: number of leaves, plant diameter and chlorophyll content. The parameters: genetic, phenotypic, environmental and additive variance, the dominance in F2, heritability in the broad and narrow-sense, the average degree of dominance based on averages, number of genes, the measure of the dominance deviations, additive effects and all interactions of ‘additive x additive’, ‘additive x dominant’ and ‘dominant x dominant’ type, were evaluated. Chlorophyll content was the most influenced by the environment. Plant diameter had the highest narrow-sense heritability for the cross UFU-Lisa-124#2#1 x UFU-Albina#3 (82.1%). The number of genes for the number of leaves varied from inconclusive to a minimum of 9 genes. The gene interactions for number of leaves were of overdominance type, while for plant diameter and for chlorophyll content the gene interactions were of partial dominance. The characteristics are suggested as being of polygenic or oligogenic nature.

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