| Analysis of wheat mutants for straw and leaf characteristics
A.S. LARIK, H.M.I. HAFlZ* and M.B. KUMBHAR Department of Plant Breeding and Genetics, Sind Agricultural University, Tandojam, Pakistan In recent years very useful models of production processes have been developed by DEWIT (1965) and DUNCAN et al (1967), using straw and leaf characteristics as architectural elements influencing grain yield. The recognition of genetic variation in any character which is envolved in the synthesis of yield leads to the possibility of crop improvement and in this context all stages of plant growth and development are of importance (BELL and KIRBY, 1966). Enhanced characters may be transfered from the donor parent to a gene pool from which improved genotypes may be developed. This assembling of attributes into a genotype follows the concept of ideotypes (DONALD, 1968), although the success of such improvement programme depends on the expression of the enhanced characters in the new genetic background and against the interaction of environmental factors. In present studies data on straw and leaf characteristics of wheat mutants were analysed and correlated with grain yield. While operating a breeding methodology, it seems obvious that selection is likely to change two or more characters simultaneously and a plant breeder must therefore exert different magnitude of pressures on various attributes. Material and Methods Four high yielding mutants (No's 27, 31, 35 and 44) derived from Nayab (Mexican origin) were investigated along with control during Rabi 1978-79. Morphological traits of agronomic significance were studied with reference to straw architecture and leaf characteristics that contributes toward yield. The first three spikes (ontogenetically) of each M9 mutants were used to raise M10 generation. Sowing of homogeneous seeds of mutants and cultivar was done by dibbling single seed per hole at 30.5 cm intervals in single row each 3.1 m long with 30.5 cm interrow distance with path ways 1.0 m wide between blocks of a plot in randomized block design with four replications accomodating 31 plants in each replication on fertile soil type at the Botanical Garden, Sind Agricultural University, Tando Jam, Pakistan. Data on 10 randomly selected M10 Plants in each replication were recorded for ten metrical traits Viz., plant height, first internode length, second internode length, third internode length, harvest index, first flag leaf length, first flag leaf width, second flag leaf length, second flag leaf width and first flag leaf L/B ratio. Thus 40 plants were studied from each mutant genotype. The data was analysed statistically and the mean values were used to calculate coefficient of correlation. Harvest index was calculated after DONALD (1962). HI expressed in percentage, gives the ratio of the economic yield (grain yield) and the biological yield (total dry matter) as follows: Harvest Index (HI) = (Economic Yield / Biological Yield) x 100 |
| * Associate Professor, Department of Botany, Punjab University, Lahore, Pakistan. |
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