engleski

Variation in the yield and yield components of winter wheat genotypes

Main goals of winter wheat breeding are increase of grain yield and achieving high quality requirements. Winter wheat yield, as a complex trait, depends of various plant traits and it is influenced by genotype and agroecological conditions (Drezner et al., 2007). Variations in yield and yield components influence breeding work on winter wheat and can hinder selection of high yielding and quality genotypes. Splitting genetic variation of yield and yield components in parts of variations using principal components analysis (PCA) can improve selection of superior winter wheat genotypes. The objective of this paper was to determine variations between examined winter wheat genotypes analyzing yield and six traits important for yield formation: hectoliter weight, thousand kernels weight, plant height, number of ears per m/2, number of spikelets per ear and number of kernels per spikelet. Research work included 25 winter wheat genotypes, 22 of them were new breeding lines and three were recognized varieties Žitarka, Srpanjka and Divana. Žitarka and Srpanjka are high yielding varieties while Divana is high quality variety. The PCA of analyzed traits revealed that 75.41% of the variation could be captured within first three principal components (PC1 to PC3). These components had eigenvalues grater that 1.0. The first principal component had an eigenvalue of 2.27 explaining 32.39% of the whole variation. Number of ears per m/2, number of spikelets per ear, and number of kernels per spikelet contributed strongly to variation for this principal component with eigenvectors above 0.7. Number of spikelets per ear and number of kernels per spikelet were in strong positive correlation while the number of ears per m/2 was in negative correlation with these two traits. The second principal component’ s eigenvalue was 1.69 and it explained 24.20% of total variation. To the variation of this principal component strongly contributed yield, thousand kernels weight and plant height with eigenvectors above 0.5. These traits were in negative correlation. The third principal component’ s eigenvalue was 1.32 ; it explained 18.82% of total variation. Trait that strongly contributed to its variation with eigenvector -0.88 was hectoliter weight. PCA biplot showed that examined genotypes formed three groups around three examined traits ; first group was around thousand kernel weight, second around number of spikelet’ s per ear and third around yield. Varieties Žitarka and Srpanjka grouped close together while Divana was on the opposite side. That was expected since Žitarka and Srpanjka have high yield, number of ears per m/2 and short plant. On the other hand Divana has higher plant, lower yield and number of ears per m/2, but it has high quality parameters.

winter wheat ; yield ; genotypes ; spikelets per ear ; number of kernels per ear

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