Molecular Clustering and Interrelationships among Agronomic Traits of Jordanian Barley Cultivars

Abstract

To make barley breeding programs more effective, comprehensive information on the amount of molecular diversity in barley cultivars and on interrelationships among agronomic traits is needed. Path-coefficient and principal-component analyses were used to study the interrelationships among barley grain yield and various grain yield components. Eleven amplified fragment-length polymorphism (AFLP) primer combinations were used to cluster barley cultivars into distinct groups. Path analysis across cultivars showed that number of fertile tillers per plant had the largest positive direct effect (0.94) on grain yield, followed by biological yield (0.491), and spike weight (0.357). However, number of tillers per plant (−0.917) and spike length (−0.263) showed negative direct effects. Principal component analysis using GGEbiplot showed that ‘Rum’ cultivar had the highest values for biological yield, spike weight, plant height at maturity, leaf width, peduncle length, and days to heading. It also had the highest grain yield, followed by Acsad-176; the other three cultivars yielded below average. This cultivar separation was confirmed by cluster analysis. Such molecular and morphological differentiation should be of great help for barley breeding programs.