Implications of Genetic Heterogeneity Among Cultivated Genotypes for Global Food Security in Climate Change Era

The experiment was undertaken in three water stress environments to assess the inherent diversity of the primary gene pool of sunflower (Helianthus annuus L.) following morphophysiological criteria and thereafter validation of these genotypes in the current trend of climate change. Plot achene yield was maximum in control and ranged from 10.3g to 54.7g in W1, 7.2 to 52.2 in W2, 9.7 to 49.8 in W3 and 10.0 to 51.8 in W4.The genotypes P-94-R, P-115-R and P-119-R were found to be severely affected by the treatments, however, 95-C-1-R and P-87-R resisted to water stress and showed minimum reduction in seed yield. D2 statistics grouped the test genotypes into 6 clusters. Cluster I comprised of maximum number of genotypes (27 genotypes), followed by cluster II (5 genotypes), cluster III and V (3 genotypes in each), cluster IV (2 genotypes), and cluster VI (1 genotypes). Among the traits evaluated, leaf area index contributed the maximum (18.54%) towards the observed diversity, followed by early vigour (18.35%), oil content (12.35%), 100 seed weight (10.59), photosynthetic capacity (9.58%), and plant height (9.29%), and leaf water potential (6.16%), achene yield per plant (4.50%), head diameter (4.19%) and canopy temperature (3.16%). Genotypes P69R, P87R, P93R, P115R, NDLR2 (Cluster I), P107RP1 (Cluster II), P121R (Cluster III), P111R (Cluster IV), 40B and 50B (Cluster V) and 7-1B (Cluster VI) identified as stress tolerant genotypes. The study concludes cytoplasmic restorer lines P111R, P112R and P110R and maintainer lines 71B, 40B and 50B as putative genetic material to comply threatening climatic phenomenon.