BREEDING AFLATOXIN RESISTANT CORN LINES
AND HYBRIDS THROUGH A COORDINATED
BREEDING AND TESTING EFFORT IN THE
SOUTHERN STATES
Wenwei Xu1, Seth Murray2, Gary Odvody3, Tom Isakeit2, Matt
Krakowsky4, Xinzhi Ni5, Paul Williams6, Dewey Lee7; Brian Scully5
1Corn
Breeder, Texas A&M AgriLife Research, Lubbock, TX 79403; 2Texas
A&M University, College Station, TX; 3Texas A&M AgriLife Research,
Corpus Christi, TX; 4Matt Krakowsky, USDA-ARS, Raleigh, NC; 5Xinzhi Ni,
USDA-ARS, Tifton, GA; 6Paul Williams, USDA-ARS, MS, 7University of
Georgia, Tifton, GA.
Objectives
• Develop new high yielding lines for making
hybrids that can yield well and also have low
aflatoxin in the southern states;
• Provide extensive testing of new inbred lines,
hybrids, and technologies in the southern
states for improving yield performance and
reducing aflatoxin risks.
Materials and Methods
Materials and Methods - Objective 1 Develop new high yielding lines for making
hybrids that can yield well and also have
low aflatoxin in the southern states
Development of a corn hybrid involves three major steps:
- Collect and evaluate germplasm
- Make breeding crosses, create segregating populations,
select desirable plants and advance them to inbred
lines.
- Make hybrids by cross inbred lines, evaluate the
hybrids and select the best ones for commercial
production.
Breeding Strategies For Aflatoxin Resistance
Drought/heat
tolerance
Tight husk
CEW/FAW
Resistance
Kernel
resistance
Association
mapping
High yielding
Low-aflatoxin
Multiple-stress
Tolerant hybrids
Gene
Expression
Coordinated
testing
New sources
of resistance
Halfway
Lubbock
Weslaco
Corpus
Christi
College
Station
Starkville Tifton
Raleigh
Gary Odvody and Tom Isakeit prepared and provided A.
flavus inoculum.
Gary Odvody conducted aflatoxin evaluation and analysis at
Corpus Christi.
Wenwei Xu:
• Focused on developing inbred lines by
using tropical and wild species
• Selecting for drought and heat
tolerance, insect resistance, and kernel
resistance to fungal infection

Selfed ears of F1
plants

Ears of BC3F1 plants
with 6.25% teosinte
germplasm.
Teo-Lines
Seth Murray:
• Continued to advance and characterize inbreds
derived from the LAMA germplasm.
• Led the expanded screening effort of evaluating
inbred lines in Weslaco and College Station.
• All 4 lines exhibit high potential for resistance to
aflatoxin accumulation
• Traits associated: kernel hardness, husk
coverage, insect resistance, etc.
• Currently selfing down selected ears for
earliness and Aflatoxin resistance
Dr. Xinzhi Ni, Dr. Brian Scully, USDA-ARS, Tifton, GA
Dr. Matt Krakowsky, Raleigh, NC
• FAW 1382 and FAW 1430
• Identified best breeding
Whorl-feeding fall armyworm
crosses.
• Evaluated 50 new breeding
crosses and 40 lines for fall
armyworm, corn earworm
damage with natural
infestation, and aflatoxin
accumulation with
inoculations.
• From GEM breeding crosses
and lines, identified new
promising germplasm.
Ear-colonizing pests
Pual Williams’s group:
• Select lines with kernel resistance to aflatoxin accumulation,
conducted genetic mapping work, and identified DNA makers for
aflatoxin resistance.
• Development of near-isogenic lines with QTLs for resistance to
aflatoxin accumulation previously identified in Mp313E and Mp715.
• Three additional populations of F2:3 families (Mp715 x Va35,
Mp313E x Mo18w , and Mp717 x PHW79) were phenotyped for
resistance to aflatoxin accumulation, and tissue samples were
collected for DNA extraction.
• Evaluated breeding crosses produced by Matt Krakowsky for
resistance to aflatoxin accumulation and identified several of these
breeding crosses exhibited low levels of aflatoxin contamination
and are potentially useful for future breeding efforts.
Marker-Assisted Selection For Aflatoxin Resistance?
• QTL markers to be validated.
• Most resistant lines are late in maturity
and need improvement in yield.
Shuttle Breeding for New Lines with Improved Aflatoxin
Resistance and Stress Tolerance
• Developed 4-way and 8-way cross populations from
known sources of resistance (Warburton et al. 2013).







Tx740:Mp313E x Tx772:Mp715
Tx772:Mp313E x Tx740:Mp715
(CML108:Mp715 x A6:Tzi8) x (Tzi18:Ki3 x NC334:Hi27)
(CML 108/NC334 x Tx740/CML 348)
x (Tzi18:Mp313E x CML 311:Mp715)
(Tzi18:CML 69 x Tzi8 x Mp313E)
x (CML108:A6 x CML311:Mp715)
• Breeders select inbred lines from these populations
across different environments, and share the
selected early generation lines.
Materials and Methods - Objective 2
- Provide extensive testing of new inbred lines, hybrids, and
technologies in the southern states for improving yield performance
and reducing aflatoxin risks.
• SERAT Tests:
- Most extensive uniform testing for aflatoxin resistance
- 41 hybrids in 2015: 9 hybrids each from Seth Murray,
Georgia, Paul Williams and Wenwei Xu, and 5 checks.
- 8 locations in Georgia (1), North Carolina (4),
Mississippi (1), and Texas (2).
- Pioneer hosted two locations in NC. Other companies
previous years.
• Other tests: more hybrids, fewer locations.
• Hybrids of ANTIGO01:N16-derived inbred lines had
low aflatoxin and high grain yield when compared
with commercial hybrids.
 ANTIG01:N16-derived lines: a useful source of
aflatoxin resistance and high grain yield.
• ANTIG01:N16 is a breeding population from GEM
project. It was made by crossing elite temperate
line and ANTIGO1 - yellow semi-dent tropical
Criollo race from Antigua.
Technology Transfer
 The 2nd AMCOE Corn Breeding Field Day was held on July 22-24,
2015 in College Station, TX.
 Material Transfer Agreements with seed companies for evaluating
our new lines and hybrids for commercialization:
 In 2014, Murray had two MTAs, Xu had two MTAs.
 In 2015, Murray had one MTA, Xu had two MTAs.
 Seth Murray is in the process of releasing inbred lines Tx741,
Tx775, Tx777, Tx779, Tx780 and Tx782.
 Wenwei Xu is the process of releasing 5 lines and filed an IP
disclosure with Texas A&M System Technology Commercialization
Office for 17 inbred lines that are available to seed companies for
evaluation and potential commercialization.
Technology Transfer – Commercial Hybrids
 Inbred lines developed by Xu have been used in
producing commercial hybrids in southern U.S.
since 2012.
 One hybrid has high grain yield, excellent grain
quality, and and low aflatoxin.
Acknowledgement
Funding from the National Corn Grower
Association/AMCOE, Texas Corn
Producers Board, USDA and other
agencies are greatly appreciated.
Thank You