Back to Contents

FREE FULL TEXT PDF

GRAPHICAL ANALYSIS OF MULTI-ENVIRONMENT TRIAL (MET) DATA  IN  SUNFLOWER (HELIANTHUS ANNUUS L.) THROUGH CLUSTERING AND GGE BIPLOT TECHNIQUE

IHSAN ULLAH, M. AYUB, ^*M. RASHID KHAN, M. ASHRAF, M.Y. MIRZA AND M. YOUSAF

Abstract: Multi-environment trial (MET) data of 10 sunflower hybrids were analyzed to: (1) group similar genotypes and similar environments into homogenous groups through cluster analysis, (2) show their interaction with each other through genotype main effects plus genotype x interaction (GGE) biplot graphic display which facilitates the visual evaluation of both the genotypes and environments, and (3) to show the performance of different genotype groups across environments and different environment groups over all genotypes through performance plots. Cluster analysis revealed 5 genotypic and 4 environment groups for seed yield (kg ha^-1) and five genotypic and 3 environment group for oil content (%). Pooled analysis showed highly significant results (P< 0.01) with Environments, Genotypes and G X E contributing 81.89, 2.59 and 11.12 % for seed yield kg ha^-1 and 51.66, 18.11 and 19.2 % for oil content respectively. The GGE biplot was constructed by plotting the primary effect scores of each genotype (as x-axis) and each environment against their respective secondary effect scores (as y-axis). In these biplots, genotypes are represented by numbers and environments by vectors generating from the origin. Biplots can be used to evaluate cultivars for their yield potential and stability and to evaluate trial sites for their discriminating ability and representiveness. Genotypes that are close together viz., G1, G4, G5 and G6 are similar in their yield performance across environments, while adjacent environments (E3, E6 and E7) having acute angle between them, are similar in the way they discriminate among genotypes. High yielding and stable genotypes (G1, G4, G5 and G6) usually tend to be on the bottom right quadrant of the joint plot. Regarding oil content (%), E1 and E5 proved to be closely related due to acute angle between them, in the way they discriminated among genotypes. Genotypes G1, G2, G4, G5, G7 and G10 are similar in their behavior across environments in terms of % oil content.

Oilseed Programme, National Agricultural Research Centre (NARC) Islamabad

^*Department of Biology, Quaid-i-Azam University, Islamabad, Pakistan.