Resistance to Aspergillus Ear Rot and Aflatoxin Accumulation in Maize F 1 Hybrids

Crop Science ◽  
2002 ◽  
Vol 42 (2) ◽  
pp. 360-364 ◽  
Author(s):  
G. Naidoo ◽  
A. M. Forbes ◽  
C. Paul ◽  
D. G. White ◽  
T. R. Rocheford
Keyword(s):  
Ear Rot ◽  
Aflatoxin Accumulation ◽  
Aspergillus Ear Rot

Resistance to Aspergillus Ear Rot and Aflatoxin Accumulation in Maize F Hybrids

Crop Science ◽  
2002 ◽  
Vol 42 (2) ◽  
pp. 360 ◽  
Author(s):  
G. Naidoo ◽  
A. M. Forbes ◽  
C. Paul ◽  
D. G. White ◽  
T. R. Rocheford
Keyword(s):  
Ear Rot ◽  
Aflatoxin Accumulation ◽  
Aspergillus Ear Rot

scholarly journals Tissue-Specific Components of Resistance to Aspergillus Ear Rot of Maize

2012 ◽  
Vol 102 (8) ◽  
pp. 787-793 ◽  
Author(s):  
Santiago X. Mideros ◽  
Gary L. Windham ◽  
W. Paul Williams ◽  
Rebecca J. Nelson
Keyword(s):  
Control Measure ◽  
Ear Rot ◽  
Maize Hybrids ◽  
Maize Germplasm ◽  
Components Of Resistance ◽  
Multiple Components ◽  
Kernel Composition ◽  
Aflatoxin Accumulation ◽  
Aspergillus Ear Rot

Aspergillus flavus and other Aspergillus spp. infect maize and produce aflatoxins. An important control measure is the use of resistant maize hybrids. There are several reports of maize lines that are resistant to aflatoxin accumulation but the mechanisms of resistance remain unknown. To gain a better understanding of resistance, we dissected the phenotype into 10 components: 4 pertaining to the response of silk, 4 pertaining to the response of developing kernels, and 2 pertaining to the response of mature kernels to inoculation with A. flavus. In order to challenge different tissues and to evaluate multiple components of resistance, various inoculation methods were used in experiments in vitro and under field conditions on a panel of diverse maize inbred lines over 3 years. As is typical for this trait, significant genotype–environment interactions were found for all the components of resistance studied. There was, however, significant variation in maize germplasm for susceptibility to silk and kernel colonization by A. flavus as measured in field assays. Resistance to silk colonization has not previously been reported. A significant correlation of resistance to aflatoxin accumulation with flowering time and kernel composition traits (fiber, ash, carbohydrate, and seed weight) was detected. In addition, correlation analyses with data available in the literature indicated that lines that flower later in the season tend to be more resistant. We were not able to demonstrate that components identified in vitro were associated with reduced aflatoxin accumulation in the field.

scholarly journals Evaluation of the MI82 Corn Line as a Source of Resistance to Aflatoxin in Grain and Use of BGYF as a Selection Tool

Plant Disease ◽  
2003 ◽  
Vol 87 (9) ◽  
pp. 1059-1066 ◽  
Author(s):  
L. M. Maupin ◽  
M. J. Clements ◽  
D. G. White
Keyword(s):  
Gene Action ◽  
Correlation Coefficients ◽  
Ear Rot ◽  
Yellow Fluorescence ◽  
Greenish Yellow ◽  
Aflatoxin Concentration ◽  
Aflatoxin Accumulation ◽  
Low Levels ◽  
Selection For ◽  
Aspergillus Ear Rot

Our objectives were to determine if the corn (Zea mays) inbred MI82 has alleles for resistance to Aspergillus ear rot (caused by Aspergillus flavus) and aflatoxin accumulation in grain that can be transferred to commercially used inbreds, and to determine the types and magnitudes of gene action, heritabilities, and gain from selection for low levels of bright greenish-yellow fluorescence (BGYF), aflatoxin, and ear rot with MI82. Also, we hoped to determine if selection against BGYF would substantially reduce the concentration of aflatoxin in grain. Primary ears and ground grain from inbred MI82 (P1), the susceptible inbred B73 (P2), and the F1, F2, F3, BCP1S1, and BCP2S1 generations developed from these inbreds were evaluated for BGYF, concentration of aflatoxin in grain, and severity of Aspergillus ear rot in 2000 and 2001. Dominance was the most important gene action associated with low levels of BGYF and a low concentration of aflatoxin in grain. Heritabilities for low levels of BGYF (83.5%), aflatoxin (74.1%), and ear rot (62.8%) were high. Correlation coefficients between aflatoxin and BGYF were high in both years (r = 0.75 and 0.79 for 2000 and 2001, respectively). Unlike aflatoxin, BGYF was not affected by the year in which plants were grown. Selection for low levels of BGYF prior to selection based on aflatoxin concentration is as effective as selection for either factor alone. MI82 has value in programs designed to improve the resistance of commercially used corn inbreds.

scholarly journals Inheritance of Resistance to Aflatoxin Production and Aspergillus Ear Rot of Corn from the Cross of Inbreds B73 and Oh516

2004 ◽  
Vol 94 (10) ◽  
pp. 1107-1115 ◽  
Author(s):  
K. N. Busboom ◽  
D. G. White
Keyword(s):  
Gene Action ◽  
Aflatoxin Production ◽  
Ear Rot ◽  
Greenish Yellow ◽  
Generation Means ◽  
Aflatoxin Concentration ◽  
Single Factor Analysis ◽  
Aflatoxin Accumulation ◽  
The Cross ◽  
Aspergillus Ear Rot

Our objective was to determine the value of corn (Zea mays) inbred Oh516 as a source of resistance to Aspergillus ear rot and aflatoxin accumulation in grain. Types and magnitudes of gene action associated with resistance were determined with generation means analysis. Molecular markers associated with resistance were identified from BCP1S1 families developed from the cross of the susceptible inbred B73 and Oh516. In 2001 and 2002, B73 (P1), Oh516 (P2), and the F1, F2, F3, BCP1, BCP2, and BCP1S1 generations were evaluated for aflatoxin concentration in grain, percent bright greenish yellow fluorescence (BGYF), and severity of Aspergillus ear rot following inoculation in Urbana, IL. BCP1S1 families testcrossed with LH185 also were evaluated at three locations in 2002. Molecular marker-quantitative trait loci (QTL) associations with all traits were determined with single factor analysis of variance. Dominance gene action was associated with aflatoxin concentration in grain and percent BGYF. QTL associated with aflatoxin accumulation in grain were identified on chromosomes 2, 3, and 7 (bins 2.01 to 2.03, 2.08, 3.08, and 7.06). Alleles from inbred Oh516 on chromosomes 2, 3, and 7 should improve resistance of commercially used, B73-type inbreds.

scholarly journals Assessing Genotype-By-Environment Interactions in Aspergillus Ear Rot and Pre-Harvest Aflatoxin Accumulation in Maize Inbred Lines

Agronomy ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 86 ◽  
Author(s):  
Sheila Okoth ◽  
Lindy Rose ◽  
Abigael Ouko ◽  
Nakisani Netshifhefhe ◽  
Henry Sila ◽  
...  
Keyword(s):  
Inbred Lines ◽  
Ear Rot ◽  
Genotype By Environment Interactions ◽  
Genotype By Environment ◽  
Maize Inbred Lines ◽  
Aflatoxin Accumulation ◽  
Aspergillus Ear Rot

Resistance to Aflatoxin Accumulation in Kernels of Maize Inbreds Selected for Ear Rot Resistance in West and Central Africa

2001 ◽  
Vol 64 (3) ◽  
pp. 396-400 ◽  
Author(s):  
ROBERT L. BROWN ◽  
ZHI-YUAN CHEN ◽  
ABEBE MENKIR ◽  
THOMAS E. CLEVELAND ◽  
KITTY CARDWELL ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Natural Infection ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Central Africa ◽  
Aflatoxin Contamination ◽  
Ear Rot ◽  
Screening Assay ◽  
West And Central Africa ◽  
Aflatoxin Accumulation

Thirty-six inbred lines selected in West and Central Africa for moderate to high resistance to maize ear rot under conditions of severe natural infection were screened for resistance to aflatoxin contamination using the previously established kernel screening assay. Results showed that more than half the inbreds accumulated aflatoxins at levels as low as or lower than the resistant U.S. lines GT-MAS:gk or MI82. In 10 selected aflatoxin-resistant or aflatoxin-susceptible inbreds, Aspergillus flavus growth, which was quantified using an A. flavus transformant containing a GUS-β-tubulin reporter gene construct, was, in general, positively related to aflatoxin accumulation. However, one aflatoxin-resistant inbred supported a relatively high level of fungal infection, whereas two susceptibles supported relatively low fungal infection. When kernels of the 10 tested lines were profiled for proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, significant variations from protein profiles of U.S. lines were observed. Confirmation of resistance in promising African lines in field trials may significantly broaden the resistant germplasm base available for managing aflatoxin contamination through breeding approaches. Biochemical resistance markers different from those being identified and characterized in U.S. genotypes, such as ones inhibitory to aflatoxin biosynthesis rather than to fungal infection, may also be identified in African lines. These discoveries could significantly enhance the host resistance strategy of pyramiding different traits into agronomically useful maize germplasm to control aflatoxin contamination.

Comparison of Aspergillus Ear Rot and Aflatoxin Contamination in Grain of High-Oil and Normal-Oil Corn Hybrids

2003 ◽  
Vol 66 (4) ◽  
pp. 637-643 ◽  
Author(s):  
DINA E. SEVERNS ◽  
MICHAEL J. CLEMENTS ◽  
ROBERT J. LAMBERT ◽  
DONALD G. WHITE
Keyword(s):  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Ear Rot ◽  
Male Sterile ◽  
Corn Hybrids ◽  
Growing Seasons ◽  
High Oil Corn ◽  
Corn Kernels ◽  
Aspergillus Ear Rot ◽  
Corn Grain

High-oil corn (Zea mays L.) grain is a valuable component of feed for monogastric livestock. One method of increasing the concentration of oil in corn grain is the TopCross method. With TopCross, ears of a cytoplasmic male-sterile, normal-oil hybrid are pollinated by a male-fertile, high-oil synthetic hybrid. The concentration of oil in the resulting grain is increased because of xenia effects. Kernels of high-oil corn typically have a larger germ and a smaller endosperm than kernels of comparable normal hybrids. The growth of Aspergillus flavus Link:Fr within germ tissue has been reported to be more extensive than that on the whole corn kernel; therefore, the severity of Aspergillus ear rot could be more extensive and aflatoxin concentrations could be higher in high-oil grain produced by TopCross than in grain with a lower concentration of oil. The objective of this study was to compare Aspergillus ear rot severity levels and aflatoxin concentrations in the grains of hybrids crossed with high-oil or normal-oil pollinators. Fifteen hybrids were evaluated in 1998 and 1999 in Urbana, Ill. Primary ears were inoculated with A. flavus and evaluated for susceptibility to Aspergillus ear rot and aflatoxin production in grain. Concentrations of aflatoxin and oil in corn kernels were significantly higher for high-oil hybrids than for normal-oil hybrids; however, ear rot severity was unaffected by the type of pollinator. These results suggest that grain from high-oil hybrids is at greater risk for aflatoxin contamination during some growing seasons.

Sign in / Sign up

Export Citation Format

Share Document