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STUDIES ON GENETIC VARIABILTY AND SELECTION GAIN IN SEGREGATING GENERATIONS FOR YIELD AND BRAN OIL CONTENT IN RICE (Oryza sativa L.)

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Title STUDIES ON GENETIC VARIABILTY AND SELECTION GAIN IN SEGREGATING GENERATIONS FOR YIELD AND BRAN OIL CONTENT IN RICE (Oryza sativa L.)
 
Creator MAHESH BABU PEBBETI
 
Contributor CHANDRA MOHAN, Y
 
Subject yields, selection, rice, genetics, developmental stages, grain, oils, planting, humus, biological phenomena
 
Description In the present investigation, 200 progenies of four crosses of rice were evaluated
to study the genetic variability and selection gain in segregating generations, to estimate
the genetic parameters among the progenies for yield and bran oil content and the extent
of association between the yield and its component characters including the direct and
indirect effects. The experiment was laid out in a randomized block design with two
replications at Indian Institute of Rice Research (IIRR) farm, International Crops
Research institute for Semi Arid Tropics (ICRISAT) campus, Patancheru, Hydarabad,
during Kharif, 2014.
Analysis of variance indicated the existence of significant differences among the
progenies for all the traits under study. High GCV and PCV values were observed for
number of filled grains per panicle and total number of grains per panicle. High
heritability coupled with high genetic advance was observed for plant height, number of
filled grains per panicle and total number of grains per panicle indicating the
predominance of additive gene effects in controlling the character. Hence, the
improvement in these characters could be possible through simple selection. However,
high heritability coupled with low genetic advance was observed for number of
productive tillers per plant, panicle length, kernel length, 1000-grain weight and bran oil
content indicating the predominance of non-additive gene effects in controlling the
character. Hence, the improvement in these characters is not possible through simple
selection and requires recurrent selection or heterosis breeding for improvement.
Highest selection intensity was observed for the crosses Keshari x NDR359 and
Keshari x IR-64, whereas lowest selection intensity was observed for the cross Keshari x
Swarna. When comparing selection intensity between F2 & F3 generations, it was
increased for all crosses studied in the experiment, indicating that the selections were
progressed towards yield improvement. Selection gain is greater than the expected mean
yield in F3 generation for the cross Keshari x RPBio226 and Keshari x Swarna and
further increased for both crosses in next generation, indicating that selection is
effective for that particular character. Selection gain is lower than expected mean yield
for the cross Keshari x IR-64 and Keshari x NDR359 and decreased for both crosses in
next generation, indicating that selection is ineffective for grain yield.
Character association studies revealed that the character grain yield per plant
showed significant positive association with number of productive tillers per plant,
number of filled grains per panicle, total number of grains per panicle, spikelet fertility
and 1000-grain weight. This indicated that simultaneous selection of all these characters
were important for yield improvement.
A critical analysis of the results by path analysis revealed that total number of
grains per panicle exerted the highest positive direct effect on grain yield followed by
spikelet fertility, 1000-grain weight, number of productive tillers per plant, L/B ratio,
kernel breadth, panicle length, days to 50% flowering, days to maturity, indicating that
the selection for these characters was likely to bring about an overall improvement in
grain yield per plant directly.
High bran oil content (>15%) was recorded in seven progenies of Keshari x IR-64
(i.e. 1st, 5th, 7th, 13th, 35th, 36th & 37th progenies), five progenies of Keshari x RPBio226
(i.e. 6th, 7th, 17th, 18th & 19th progenies), three progenies of Keshari x Swarna (i.e. 17th,
21st & 31st progenies), and three progenies of Keshari x NDR359 (i.e. 2nd, 3rd & 43rd
progenies) and these superior progenies can be further promoted to get high bran oil
content.
 
Date 2017-01-03T09:40:54Z
2017-01-03T09:40:54Z
2015
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/94033
 
Language en
 
Relation D9897;
 
Format application/pdf
 
Publisher PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY. HYDERABAD