cl formal presentation
TRANSCRIPT
Correlation Between Early Phenotypes and Survival Rate for Commercial Maize
Lines and Fusarium graminearum
Objectives
1. We will evaluate if the maize genotype and/or fungal genotype determines the plant’s level of resistance to F. graminearum infection.
2. We will determine if seedling height, sheath elongation, third leaf emergence, or root length is correlated with survival rate and can be used as a predictor of disease severity.
Methods
D9:• Total root length is the sum of the primary
root length and length of all lateral roots, measured with the RootReader 2D software.
D3, D5, D7,D9:• Sheath length is the distance
between the crown root emergence point and band marking where the cotyledon splits off from the stalk.
• Seedling height is the distance between the crown root emergence point and tip of the seedling.
• Third leaf emergence is the age at which the distance from the band marking to the tip of the second true leaf exceeds 4 cm.
D14:• Survival rate is the proportion of healthy
seedlings to total seedlings. Healthy seedlings are defined by three criteria:
1. The first and second true leaves are upright and green.
2. The stem is straight and rigid.3. The roots are generally white and do
not show the signs of decay (ex. browning, shrinkage).
third leaf emergence
seedling height
sheath length
Survival rate vs. maize and fungal genotypes
• survival rate vs. fungal isolate (absolute values of data) => discuss general pattern that survival rate heavily affected by fungal isolate’s aggressiveness (supported by NOVA analysis’s p-value) => we need to transform data into numerically ranked– compare Gz & Maize columns for same phenotype (less variation within each fungal isolate)
fungal genotype & maize genotype both contribute to “health”/survival rate, but fungal genotype is more important in determining phenotype
• Excel graph of survival rate vs. fungal isolate (data numerically ranked for each fungal genotype) =>
• Excel graphs of survival rate vs. early phenotypes => discuss potential predictors (supported by R2)
0.80 1.00 1.20 1.40 1.60 1.80 2.000.00
0.20
0.40
0.60
0.80
1.00
R² = 0.197856696444336R² = 0.114489016388204
Seedling Height 3 DPI
Heal
th R
ate
-1.00 -0.80 -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60 0.80 1.000.00
0.20
0.40
0.60
0.80
1.00
R² = 0.211251269018694
Third Leaf Emergence 7 DPI (%)
Heal
th R
ate