Genetic variation and inter-relationship between morphological characteristics and grain yield in advanced bread wheat (Triticum aestivum L.) cultivars using multivariate analysis

Genetic diversity of 30 varieties of advanced bread wheat (Triticum aestivum L.) was studied. A field experiment was conducted using a randomized complete block design with four replications at the Research Farm of Islamic Azad University, Miyaneh Branch in 2009. All agronomic practices were carried out by current procedure. Nineteen traits included days to germination, stem elongation, heading, physiologic maturity, ripening, awn length, leaf number main stem, flag leaf area, penultimate flag leaf area, plant height, peduncle length, number of spike/m2, grain numbers/spike, 1000 grains weight, biologic yield, harvest index, grain filling period, straw yield and grain yield were measured. Data were analyzed using multivariate techniques like principle components, stepwise regression and cluster approaches. Principal components analysis showed that first and second components could explain a 75.51% of total variations. Based on the characteristics in the first and second components, first components were considered for yield and the second one for phonology traits. Stepwise regression analysis for grain yield as a dependant variable and other characters as independents revealed that grain number/ spike, spike/ m2, plant height and main spike length could explain 98.7% of the variations. Finally, examined variety were grouped in three clusters and the third cluster contained 23.3% of total variations which presented higher grain yield than the first and second groups. According to the results obtained in this study, N-76-16 line could be introduced as a high-performance genotype and would have advantages in the breeding programs.