Data from: Evaluation of combining ability in expired plant variety protection maize lines for southern U.S. adaptation and aflatoxin resistance
Data files
Sep 03, 2026 version files 429.82 KB
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Data_from_Knoll_et_al_2026.xlsx
426.59 KB
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README.md
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Abstract
Contamination of maize (Zea mays L.) grain with aflatoxin, produced by the fungus Aspergillus flavus, is a major concern in southern U.S. environments. Development of adapted hybrids with genetic resistance to aflatoxin accumulation is one strategy to mitigate this problem. Crossing inbred lines with recently expired Plant Variety Protection (ex-PVP) provides a new, relatively untested, source of germplasm with improved agronomic traits to utilize in breeding aflatoxin resistant hybrids. This study assessed the combining abilities of 32 ex-PVP lines and six aflatoxin-resistant USDA-ARS lines in four environments for yield, agronomic traits, and aflatoxin. USDA-ARS lines Mp313E, Mp715, and Mp717 had positive general combining ability (GCA) for anthesis, silking, and plant height, resulting in later-maturing, taller hybrids, though many had low aflatoxin. Mp717 consistently demonstrated negative GCA for aflatoxin level. The USDA-ARS line GT1309 had negative GCA for flowering time and plant height. Ex-PVP lines from both major U.S. heterotic groups (PHGV6, PHJ65, PHM57, LH195, F118, FBLL, LH200, LH236, and PHMK0) demonstrated a favorable combination of GCA for yield, ear rot resistance, and/or reduced aflatoxin when crossed with the USDA-ARS lines. Among tested hybrids, Mp717 × PHMK0 had positive specific combining ability (SCA) for yield and negative SCA for aflatoxin level suggesting that PHMK0 is a promising ex-PVP inbred to use in second cycle breeding.
Dataset DOI: 10.5061/dryad.6djh9w1jc
Description of the data and file structure
This dataset contains all raw data from all four environments of the study (GA-2022, GA-2023, MS-2022, and MS-2023) in Excel (.xlsx) format.
Missing data are represented by empty cells. Parents of commercial hybrid checks are unknown and are thus coded as missing data.
Files and variables
File: Data_from_Knoll_et_al_2026.xlsx
Description: Four hybrid yield/aflatoxin trials, each arranged in a 10 x 20 alpha lattice with two replications (200 entries per replication).
Variables
- Loc - Location where the plot was grown, either Tifton, Georgia (GA) or Starkville, Mississippi (MS).
- Year - Year the plot was grown (2022 or 2023).
- Env - Environment, or Location-Year combination (GA22, GA23, MS22, or MS23).
- Pedigree - Pedigree of the maize hybrid.
- Rep - Replication (1 or 2).
- I_BLK - Incomplete block in the alpha lattice design (number from 1 - 10).
- UNIT - Randomly assigned unit within the incomplete block (number from 1 - 20).
- Lat_ENTRY - Numerical identifier for each maize hybrid (number from 1 - 200).
- GT_Mp_Line - The USDA-ARS parent of the hybrid (usually used as the male parent).
- Ex_PVP - The expired-PVP parent of the hybrid (usually used as the female parent).
- Ex_PVP_Het_Group - The heterotic group of the Ex-PVP parent (SS or NSS), based on information from the PVP certificate.
- anthesis - The number of days from planting to 50% tassel (male) anthesis.
- silk - The number of days from planting to 50% silking (female anthesis).
- ASI - Anthesis-silking interval (days).
- Stand - Total number of plants in the plot, counted just before harvest.
- Ear_Ht - Height (cm) from the ground to the node bearing the topmost (primary) ear.
- Plant_Ht - Height (cm) from the ground to the tip of the tassel.
- EP_Ratio - Ratio of ear height to plant height.
- S_Lodging - Number of stalk-lodged plants, counted just before harvest.
- R_Lodging - Number of root-lodged plants, counted just before harvest.
- Total_Lodging - Sum of stalk-lodged and root-lodged plants.
- Lodging% - (Total Lodging/Stand) x 100%
- Lodging_arcsin - Arcsin-square-root transformed Lodging%. y = arsin (sqrt (x/100))
- MST - Moisture percentage in the grain at harvest.
- WGT_lbs - Raw plot weight (lbs) from the combine.
- TWT_lbs/bu - Test weight (lbs/bushel), only measured in Georgia.
- five_ear_wt_g - Shelled weight (g) of the grain from the hand-harvested ears. In Georgia, this was usually 5 ears, but up to 10 in Mississippi.
- total_wt_kg_15_5% - Total plot weight (combine + hand-harvested), adjusted to 15.5% moisture and converted to kg.
- kg_ha_15_5 - Yield in kg/ha, adjusted to 15.5% moisture.
- ER% - Ear rot percentage, estimated visually from the hand-harvested ears.
- ER_arcsin - Arcsin-square-root transformed ER%. y = arsin (sqrt (x/100))
- Afla_ppb - Aflatoxin from the hand-harvested ears, measured in parts per billion (ppb = ng/g).
- Log_afla+1 - Log-transformed aflatoxin. y = log(x + 1)