JIA-2019-11

2488 Hafiz Ghulam Muhu-Din Ahmed et al. Journal of Integrative Agriculture 2019, 18(11): 2483–2491 tolerance. Higher chlorophyll and carotenoid contents in tolerant genotypes have also been reported in earlier findings of Lichtenthaler and Wellburn (1983), Livingston et al . (2009), and Lohithaswa et al . (2013). Photosynthetic pigments (Chl a and b and carotenoid) were reduced with increase in water scarcity and those genotypes exhibited better chlorophyll contents under drought stress were categorized as drought tolerant. Photosynthetic pigment contents of wheat genotypes were affected by drought (Farshadfar and Amiri 2015). 4.3. Correlation among wheat seedling traits Correlation coefficient describes the degree of association between two variables. It is useful in plant breeding because it can indicate a predictive link that can be exploited in practice and provides the information about the association among various desired characters. In the current study, information about the association of seedling traits under normal and drought conditions may further help to develop the strategies for indirect selection (Table 4). Simple correlation coefficients of root length exhibited positively strong association with carotenoid and chlorophyll a while negatively correlated with shoot length. The same results were reported by Ahmad et al . (2006). Shoot length negatively correlated with all studied traits, but with chlorophyll a showed non-significant association. Findings of Khan et al . (2013) were not similar with these findings which observed that root length positively was correlated with shoot length. This indicated that the underground Table 3 Performance of studied wheat genotypes under drought stress Trait Best tolerant genotype Susceptible genotype Root length G61 followed by G11 and G1 G105 followed by G77 Shoot length G51 followed by G44 G3 followed by G98 Chlorophyll a G6 followed by G11 and G16 G105 followed by G77 Chlorophyll b G26 followed by G39 and G21 G98 followed by G91 Carotenoid G51 followed by G6 and G1 G77 followed by G98 G1 G3 G5 G7 G9 G11 G13 G15 G17 G19 G21 G23 G25 G27 G29 G31 G33 G35 G37 G39 G41 G43 G45 G47 G49 G51 G53 G55 G57 G59 G61 G63 G65 G67 G69 G71 G73 G75 G77 G79 G81 G83 G85 G87 G89 G91 G93 G95 G97 G99 G101 G103 G105 CTD-N CTD-D Chl b -N Chl b -D 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Fig. 3 Performance of wheat seedling traits of 105 genotypes under normal and drought conditions. CTD, carotenoid; Chl b , chlorophyll b ; N, normal; D, drought; G, genotype.