Fig. 1
Principal component analysis of chromosome substitution lines for identification of traits governing drought tolerance and genotypes with drought tolerance. (a) The principal component scores (PC1 and PC2) for identification of traits governing drought tolerance; (b) classification of 48 wheat-alien chromosome lines and the CS check based on factor scores of PC1 and PC2 for 16 trait variables. Description for (a) factor loading values for variables are indicated by black arrows radiating from the centre showing the direction (angle) and magnitude (length) and the contribution of the variables shown as the size of the circle, (b) four distinct groups are formed among the lines and the CS check (white circle). Legends for (a) 1: maximum root length (cm); 2; maximum root length: shoot length ratio (unitless); 3: number of seeds per plant, 4; number of seminal roots; 5: seed set percentage, 6: total root length (cm); 7: quantum yield of PSII (ΦPSII; unitless); 8: seed yield (g plant−1); 9: harvest index (%); 10: chlorophyll index (SPAD units);11: root volume (cm3); 12: individual seed weight (mg); 13: seminal root angle (°); 14: root diameter (mm); 15: seedling root length (cm),; and 16: thylakoid membrane damage (Fo/Fm ratio; unitless). (b) I, II, III and IV indicates four groups. 3008, Chinese Spring