Cultivar selection importance

The aim of the present study was to find whether differences could be detected in the compositions of mixture of volatile compounds sampled from the root zone of two different cultivars of barley. To have a reasonable base for a relevant genetic variation in the plant material, two cultivars with different adaptation to acid soils were selected. The sampling was done from young plants, as the establishment of the rhizosphere microflora is of importance in early stages of plant development. 

In conclusion, we have found that even young unstressed plants of different cultivars show a variation in the chemical composition of their undisturbed root zones. We suggest that this variation shows a genetic potential of the plant in its control of the root zone environment and especially of its rhizosphere microflora. We suspect that this genetic potential will be of importance in selection and adaptation of agricultural crop plants in the future. 

Resistance to insects has been successfully selected and introduced into important cultivars of a number of plant species including potatoes, wheat, corn, grapes, alfalfa, barley, beans sorghum, rice and sugar cane (25). This resistance is usually due to a combination of factors and only in a few cases is a single chemical factor identifiable as responsible for resistance (32). 

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