Abstract
In order to study of diversity and classify agro-morphological characters under normal irrigation and drought stress in spring wheat cultivars, 20 cultivars were evaluated in the research farm of University of Tabriz, Iran. According to the results, significant correlation was found between grain yield and number of spikes per plant, number of tiller per plant, number of fertile tillers, spike length, root length, root number, root volume, root diameter and root dry weight under both conditions. Moreover, 1,000 grain weight and plant dry weight had significant positive correlation with grain yield under drought stress. Factor analysis detected four and two factors which explained 96.77% and 90.59% of the total variation in normal irrigation and drought stress conditions, respectively. In drought stress condition the first factor justified 69.52% of total variation and was identified as yield factor. The second factor explained 21.07% of total variation and represented the biomass and plant height factor. Cluster analysis was based on the four and two factors obtained. According to the amount of factors for clusters obtained under drought stress, ‘Kavir’, ‘Niknejhad’, ‘Moghan 3’, ‘Darya’ and ‘Marvdasht’ were identified as the most drought tolerant cultivars. Other cluster was comprised of ‘Bahar’, ‘Pishtaz’, ‘Bam’, ‘Sepahan’, ‘Sistan’, ‘Pars’ and ‘Sivand’ and was named as the most sensitive under drought stress. Tolerant cultivars identified within the study can be used for direct culture or as genitors in breeding programs.
Highlights
All the biotic and abiotic stress factors are reducing crop production ; drought stress is the most important factor limiting yield in agricultural systems in arid and semi-arid regions (Mollasedeghi et al, 2011)
Cluster analysis can be used to identify variables which can be classified into main groups and subgroups based on similarity and dissimilarity. This technique is useful for parental selection in breeding programs (El-Deeb and Mohamed, 1999) and crop modelling (Jaynes et al, 2003). The objectives of this investigation were to evaluate the relations of different characters and to identify effective factors for yield improvement in spring wheat cultivars, grouping the tested cultivars according to the achieved factors under normal irrigation and drought stress conditions
Correlation analysis According to the results of the correlation, significant correlations were found between grain yield and number of spikes per plant, number of tillers per plant, number of fertile tillers, spike length, root length, roots number, root volume, root diameter and root dry weight under both conditions (Tables 2 and 3)
Summary
All the biotic and abiotic stress factors are reducing crop production ; drought stress is the most important factor limiting yield in agricultural systems in arid and semi-arid regions (Mollasedeghi et al, 2011). Walton (1971) used the factor analysis to identify growth and morphological traits relevant to yield in spring wheat and introduced four 666 factors which included yield components, morphological traits, spike length and the number of grain per plant. Cluster analysis can be used to identify variables which can be classified into main groups and subgroups based on similarity and dissimilarity This technique is useful for parental selection in breeding programs (El-Deeb and Mohamed, 1999) and crop modelling (Jaynes et al, 2003). The objectives of this investigation were to evaluate the relations of different characters and to identify effective factors for yield improvement in spring wheat cultivars, grouping the tested cultivars according to the achieved factors under normal irrigation and drought stress conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
