JIA-2019-11

2489 Hafiz Ghulam Muhu-Din Ahmed et al. Journal of Integrative Agriculture 2019, 18(11): 2483–2491 part of the plant plays an important role under drought stress conditions (Dhanda et al . 2004). Higher chlorophyll and carotenoids contents in tolerant genotypes have also been reported earlier by Livingston et al . (2009) and Lohithaswa et al . (2013). Ul-Allah et al . (2014) conducted an experiment and their findings related to current study in term of that shoot length is negatively correlated with root length. In this experiment, strong association exists of the carotenoid with chlorophyll a and b . Chlorophyll b had negative association with shoot length. Chlorophyll a had non-significant positive correlation with shoot length while the remaining studied traits exhibited the significant positive correlation. Present results supported with the findings of Dhanda et al . (2004). The findings of Kumar et al . (2014) were similar to present results that root length had non-significant relationship with shoot length under drought conditions. Adnan (2013) investigated six wheat genotypes for their capacity to stand under drought conditions. The results of Khan et al . (2002) were similar with this experiment. The relationship between chlorophyll a and b was positive and highly significant while both negatively correlated with carotenoids. The results of Khan et al . (2010) were similar with these findings. Ghafoor et al . (2013) evaluated physiological traits as indicators of drought tolerance in wheat and concluded that those genotypes which possessed higher chlorophyll contents resist more against drought than genotypes which possessed lower chlorophyll contents. Various responses of the trait under different environments for correlation may be due to the different response of genotypes under different environments. The obtained results are in accordance with the findings of Khan et al . (2002) and Dhanda et al . (2004). The parameters that were negatively correlated can affect the performance of other during the selection process. As root length, chlorophyll a , b , and carotenoid were positively correlated among themselves in both environments, therefore, selection of any one of these traits, enhances the performance of other traits. As the shoot length was non significant and negatively correlated with all other traits, so selection for shoot length seems not to be the promising criterion for this material. 5. Conclusion On the basis of performance, 105 wheat genotypes at the seedling stage of studied traits under normal and drought conditions were classified as drought tolerant and drought susceptible. Those genotypes performed better among 105 spring wheat genotypes were categorized as drought tolerant and those having the lowest performance under both environments were classified as drought susceptible. So using this criterion, 10 genotypes (G1, G6, G11, G16, G21, G26, G39, G44, G51, and G61) were selected as drought tolerant and five genotypes (G3, G77, G91, G98, and G105) as drought susceptible. Strong association amongst the photosynthetic attributes under drought condition indicated the significance of these indices for future wheat breeding programs for rainfed areas. Shoot length was non significant and negatively correlated with all other traits, so adequate attention should be given to the negatively correlated seedling parameters during selection. Acknowledgements The authors gratefully acknowledge the National Key R&D Program of China (2018YFD0200500) for the financial support. Appendix associated with this paper can be available on http://www.ChinaAgriSci.com/V2/En/appendix.htm References Adnan M. 2013. Effect of drought stress on the physiology and yield of the Pakistani wheat germplasm. International Journal of Advanced Research and Technology , 2 , 419–430. Table 4 Correlation matrix among wheat seedling traits under normal and drought conditions Trait Environment Root length Shoot length Carotenoid Chlorophyll a Shoot length Normal 0.11 ns Drought –0.33 ** Carotenoid Normal 0.46 ** –0.04 ns Drought –0.47 ** 0.15 ns Chlorophyll a Normal 0.42 ** 0.07 ns 0.68 ** Drought 0.44 * 0.01 ns 0.65 * Chlorophyll b Normal 0.51 * –0.24 * 0.58 ** 0.48 * Drought 0.48 ** 0.02 ns 0.62 ** 0.82 ** * and ** , significant at P =0.05 and P =0.01, respectively; ns, non significant.