Genomic characterization of a core set of the USDA-NPGS Ethiopian sorghum germplasm collection: implications for germplasm conservation, evaluation, and utilization in crop improvement

Table 5 Principal component analysis of 16 phenotype traits evaluated in 374 accessions from NPGS Ethiopian germplasm collection

Trait	PC1	PC2	PC3	PC4
Phenols¹	0.37*	−0.08	−0.31	0.09
Protein²	0.35*	−0.05	0.30*	0.25
Tannins³	0.36*	−0.05	−0.33	0.08
3-DOAs⁴	0.31*	−0.21	0.20	0.03
Plant height⁵	0.08	0.57*	0.12	−0.10
Length⁶	0.09	0.57*	−0.21	0.28
Diameter⁷	0.29	0.34*	−0.02	−0.48
Dhurrin ⁸	0.10	−0.03	0.38*	0.04
Ratio⁹	−0.13	0.18	−0.18	0.70*
Flowering¹⁰	0.05	0.28*	0.23	−0.10
Seed Size¹¹	−0.31	0.00	0.20	0.07
Fat²	0.25	0.15	0.18	0.04
Fiber²	−0.29	0.13	−0.05	−0.06
Ash²	−0.33	0.13	0.26	0.03
Starch²	−0.20	0.03	−0.47	−0.29
G15	0.01	−0.14	−0.08	−0.02
% Variance	24.4	13.6	12.6	9.90
% Cumulative	24.4	38.0	50.6	60.5

Phenotype evaluations were completed at Isabela and Mayaguez, Puerto Rico in 2013 and 2014
¹Total phenols based on milligram of gallic acid equivalent (GAE)/gram
²Values are based on percent
³Condensed tannins based on milligram of catechin equivalents (CE)/gram
⁴3-Deoxyanthocyanidins content based on absorbance (abs)/milliliter/gram
⁵Plant height refer to the distance from the base of the main stalk to the top of the panicle without sorghum converted accessions
⁶Panicle length refers to the distance from the base to the top of the panicle
⁷Panicle diameter refers to the wider region
⁸Dhurrin content in leaf measure at post-flowering stage using HPLC [53]
⁹Ratio refers to the length/diameter
¹⁰Flowering time refers to days to 50% flowering of the plot
¹¹Seed size refers to the volume of 100 seeds
* most important variable in the component

ISSN: 1471-2164