Inheritance Studies In Barley

Author : Ali Bayraktar
Publisher :
ISBN 13 :
Total Pages : 112 pages
Book Rating : 4.:/5 (999 download)

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Download or read book Inheritance of Plant Height in Barley (Hordeum Vulgare L. Emed. LAM.) written by Ali Bayraktar and published by . This book was released on 1972 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four, six-rowed, spring barley cultivars were used as parental material in this study. The parents were distinctly different in plant height. Washington-6124-62 is a standard height selection while Short Wocus and Minn. 66-102 are intermediate. The fourth parent was a dwarf selection obtained from India. The two intermediate cultivars and the dwarf cultivar were crossed to the tall parent, Wa-6124-62, with a portion of the F1 progeny backcrossed to the shorter parent. In addition, the intermediate parent, Short Wocus, was crossed to Indian Dwarf. The following generations were available for study: parents, BC1F1, F1, and F2. The purpose of this study was to obtain information concerning the inheritance of plant height and to determine when selection for this trait could be made in the breeding program most effectively. To achieve this objective heritability and the mode of gene action were studied as well as number of genes segregating for plant height. The effect of temperature on plant height was also investigated in a growth chamber utilizing two temperature levels, 19° C and 30° C. Plant height was recorded on an individual plant basis at two sites that were distinctly different environmentally and in the growth chamber. The number of nodes were counted, and the length of internodes measured for genetic interpretation of culm length. Broad sense heritability values for plant height of each cross were estimated by using the variance of parents, F1's and F2' s. Heritability values were quite high in the F2 generation ranging from 50 to 90 percent, and suggest that plant phenotype gave a relatively good indication of the genotype for plant height. Height of the F1 plants was between the mid-parent and tall parent indicating partial dominance for tall culm length. In earlier studies, many investigators found that additive gene action was the major component of genetic variability for plant height. Results obtained from this study suggest that the nature of gene action is a function of the parents used. Where large differences exist between parents, plant height appeared to be largely influenced by non-additive gene action. When the parents were similar in height the trait was controlled mainly by additive gene action. Fairly discrete height classes in the segregating populations indicated that plant height was controlled by only a few genetic factors in these populations. Ratios obtained from segregating populations suggested the presence of three recessive genetic factors for short height in the dwarf parent (Indian Dwarf). The tall parent, Wa-6124-62, and intermediate parent, Minn. 66-102, appeared to differ for plant height by one major genetic factor. Difference in height among the cultivars was mostly due to difference in internode length rather than the number of nodes. It was concluded that the rather simple inheritance of plant height in barley will allow effective selection in the F2 generation for short stature, and progress to develop semi-dwarf barley cultivars should be possible if stiffness of straw can also be obtained along with short stature. In the cross between the tall and dwarf parent, selection for intermediate plant height would be more effective if delayed for several generations of selfing due to the relatively large dominance component of genetic variance.