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EFFICIENCY OF EARLY GENERATION SELECTION :tl'OH INDUCED MICROMUTATIONS IN BLACKGRAM (Vigna mungo (L.) Hepper)

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Title EFFICIENCY OF EARLY GENERATION SELECTION :tl'OH INDUCED MICROMUTATIONS IN BLACKGRAM (Vigna mungo (L.) Hepper)
 
Creator Charumathi, M
 
Contributor Brahmeswara Rao, M.V
 
Subject mutagens
 
Description The mutagenic effects of gamma rays (single and
fractionated doses}, chemical mutagens EMS (0.4%), NMU
(0.01~%) and their combination treatments were studied on
black~ram, variety LBG-17 to assess effectiveness of these
mutagens on various quantitative characters, the character
association, heritability and genetic gain in M2 and M3
generations.
Macromutations including chlorophyll and morphological
mutants such as extre~ยท dwarf and tall plants, early and
late flowering, fasciated mutant, unifoliate, tetrafoliate
and round leaf mutants, brown seed mutants were observed in
M2 and M3 generations.
The direct, fractionated treatments of higher gamma ray
dose (40kR} and combination treatments of higher ~aroma ray
dose with EMS or NMU showed more drastic effects for almost
all the characters studied.
There was decrease in the efficiency of treatment as
the dose increased among the direct doses, fractionated and
combination treatments for days to flowering, days to maturity
and plant height in M2 and M3 . For these characters
selection can be done mostly in M2 there by time and effort
can be economized.
All the treatments in both the generations exhibited
higher pollen sterility percentage than their controls. The
mean per cent of pollen sterility increased with increase in
dose. However, the per cent of pollen sterility was much
lower in M3 than in M2 .
High amount of variation was induced by mutagenic
treatments for number of branches, number of pods per plant,
pod length, seeds per pod, seed yield per plant, 100 seed
weight and protein per cent in M3 generation than in M2 .
For these characters selection can be d~ne in M3 generation.
It is reasonable to assume that the variability generated by
the mutagenic treatments starts manifesting in M2 , which is
the first segregating generation. Further, segregation for
the polygenic systems in M3 is expressed as release of
additional variability. This being the mechanism of induction
and inheritance of micromutations, selection in M2 can
certainly help in identifying progenies that are likely to
show more variability and better response to selection, and
simultaneously reduce the volume of material by rejecting
'roughage'.
Medium to high estimates of heritability with moderate
to high expected genetic advance were recorded for almost
all characters under study in M3 than M2 except for
proteinper cent where very low expected genetic advance
values were recorded in both the generations.
Correlation studies revealed that single plant yield
exhibited a strong positive and significant association with
days to 50% flowering, days to maturity, plant height,
number of branches per plant, number of pods per plant,
number of seeds per pod, pod length and protein per cent in
M3 generation. The shifts in the direction in association
of various characters were observed from M2 to M3 generation
and most correlations were positive and significant in M3
than in M2 .
 
Date 2017-01-20T09:37:51Z
2017-01-20T09:37:51Z
1992
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/97229
 
Language en
 
Relation D3926;
 
Format application/pdf
 
Publisher ANDHRA PRADESH AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD