STUDIES ON THE INDUCED VARIABILITY FOR QUANTITATIVE CHARACTERS IN M3 GENERATION OF RICE VARIETY AKSHAYA (BPT 2231)
Loading...
Files
Date
2012
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
Abstract
The present investigation was carried out during kharif 2011, at
Agricultural College Farm, Bapatla, with twenty five mutagenic treatments on
rice variety Akshaya (BPT 2231) to obtain information on the nature and extent
of induced mutations, variability, heritability, genetic advance and character
association, the magnitude of direct and indirect effects of yield components on
yield in M3 generation.
Considerable amount of variability was observed for all the fourteen
characters viz., plant height, number of productive tillers per hill, days to 50%
flowering, number of fertile grains per panicle, spikelet fertility, panicle length,
test weight, grain yield per plant, kernel length, kernel breadth, L/B ratio,
amylose content, protein content and alkali spreading value.
From the results of present study it may be concluded that majority of the
morphological mutations observed in M3 generation were obtained from
combination treatments of EMS particularly with 30 Kr series followed by 40 Kr
series. Among all types of visible morphological mutations, dwarf plant types
occupy the major share followed by tall plants and early maturing genotypes.
When compared with untreated Akshaya variety, the treatments T 2, T 3 and
T 21 induced dwarf and early flowering mutants. In addition, these mutants
possess all quality parameters in the desirable range which gives immense scope
for isolation of improved variety with medium duration and slender grain type
without changing the original Akshya plant type. The mutants isolated from T 3
treatment possess more number of fertile grains per panicle among all induced treatments studied. From the treatments T 3, T13, T14, T16 and T21 mutants
were isolated with 8-10 % higher yield advantage which will be isolated in the
further generations of study. The treatments T 15 and T 16 induced mutants with
long slender grain type while from the treatment T18, long bold grain types were
isolated. The treatments T 3, T15, T16 and T21 induced mutants with straw
coloured husk. Based on the above results, it may be concluded that from the
variability induced in the present study would give scope for selection of early
maturing plants combining dwarf plant stature and high yield potential from
advanced generations.
The results of genetic parameters revealed that moderate to high GCV,
PCV coupled with high heritability and moderate to high genetic advance as
percent of mean were observed for plant height, number of fertile grains per
panicle, grain yield, test weight and alkali spreading value suggesting the
predominance of additive type of gene action in controlling these traits. The
remaining characters under study viz., number of productive tillers per hill, days
to 50 % flowering, spikelet fertility, panicle length, test weight, kernel length,
kernel breadth, length-breadth ratio and protein content manifested low GCV,
PCV, high heritability estimates along with low to high genetic advance as
percent of mean indicating the operation of both additive and non-additive gene
effects in the inheritance of these traits.
Character association studies indicated significant positive association of
plant height, number of productive tillers per hill, number of fertile grains per
panicle, spikelet fertility, test weight and kernel length with grain yield per plant.
Hence, selection of these traits would be more effective to bring simultaneous
improvement in grain yield and to evolve high yielding varieties in rice.
Negative and significant association was observed between days to 50%
flowering and grain yield.
Path coefficient analysis revealed that plant height, number of productive
tillers per hill, number of fertile grains per panicle, spikelet fertility, and test
weight showed a positive direct effect. These parameters also manifested
significant positive correlation with grain yield per plant at both phenotypic and
genotypic level. Hence, these traits may be given prime importance for the direct
improvement of grain yield.
Description
Keywords
grain, rice, planting, yields, developmental stages, genotypes, genetics, fertilizers, biological phenomena, phenotypes