Table 1. Partitioning the variance in PEV attributed to genetic and environmental factors.

	Principal Component 1		Principal Component 2
Variable	Proportion of Variance (%)	P-value	Proportion of Variance (%)	P-value
Among line	27.7	<1.0 × 10−22	15.3	<1.0 × 10−22
Second chromosome	50.9	<1.0 × 10−22	<0.1	0.88
Vial	<0.1	0.33	<0.33	1.6 × 10−6
Among line × second chromosome	1.9	<1.0 × 10−22	31.2	<1.0 × 10−22
Within line and residuals	19.5	—	53.2	—