Pak. J. Bot., 35(2): 167-174, 2003. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
RELATIONSHIP AMONG YIELD COMPONENTS AND SELECTION CRITERIA FOR YIELD IMPROVEMENT IN WINTER RAPESEED BRASSICA NAPUS L.) NAAZAR ALI, FARZAD JAVIDFAR*, JAFARIEH YAZDI ELMIRA* AND M. Y. MIRZA
Abstract: Twenty-five winter type rapeseed varieties introduced
from diverse sources of the world were studied for variability, heritability,
genetic advance, correlation and path analysis of seed yield and yield
components. Significant differences among genotypes for most of the
traits indicated that there is sufficient variability available to have
an effective selection. Genotypic and phenotypic variances were highest
for pods/plant followed by plant height, whereas the maximum genotypic
and phenotypic coefficients of variability were found in seed yield/plant
and pods/plant, respectively. Broad sense heritability estimates ranged
from very low to high. Maximum heritability of 0.903 was obtained for
days to maturity followed by flower duration (0.662), seed weight (0.548)
and seed yield (0.477). High heritability for flower duration, seed
weight and seed yield coupled with high genetic advance indicated that
these traits could be improved through mass selection. Positive and
significant correlation was found between seed yield and harvest index,
seed weight and flower duration. Significant and positive correlation
of seed weight with harvest index, flower duration and seed yield indicated
that improvement in seed weight will give higher harvest index ultimately
resulting high seed yield. Harvest index, seed weight and pods/plant
have shown a considerable direct positive effect on seed yield. Positive
direct effect of seed weight and harvest index associated with significant
and positive correlation with seed yield suggested that these yield
components may be a good selection criteria to improve seed yield of
winter type rapeseeds. Oilseed Research Program, National Agricultural Research Centre, Islamabad, Pakistan. |
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