| dc.description.abstract | The experiment was conducted at Plant breeding Research Field during transplant Aman
season (July-December) of 2016. The experimental materials comprised with 32
advanced generation (F4) derived from eight crosses involving six fine rice parental lines.
A total of thirteen characteristics viz. plant height (cm), productive tillers/hill (maximum
vegetative stage), panicle length (cm), fertile grains/panicle, sterile grains/panicle,
panicle weight (g), sterility percentage (%), lodging percentage (%), 1000-grain weight
(g), grain yield/hill (g), days to 50% flowering, days to maturity and harvest index were
studied to assess genotypic and phenotypic correlations and genetic diversity pertained
among the advanced lines. The analysis of variance showed significant difference among
each of the selected traits in the advanced lines. The means of different traits were
separated by DMRT test, the advanced line, PL6 derived from Kataribhog x Chinigura
produced the highest grain yield/ hill (41.51g) but ranking of the advanced lines based on
yield enhancing traits, PL5 derived from the same cross showed the best performance.
Among the 13 characteristics, fertile grains per panicle, panicle weight and 1000-grain
weight exhibited positive and significant correlation with grain yield both at genotypic
and phenotypic levels, suggested inherent association of these traits to increment grain
yield in the advanced lines. All the 32 advanced lines were incorporated in the genetic
diversity analysis based on 13 traits. The lines were distributed into six clusters; cluster II
comprised with eight lines and the cluster V only with two lines. The intra-cluster
distance was maximum (1.232) in the cluster V, indicated two advanced lines included in
the cluster were relatively more diversified from each other. The inter-cluster distance
(16.594) was between the cluster I and V. Therefore, further genetic diversity might be
extended through crossing or direct selection of promising parental lines. Since the main
objective of breeding is to increase yield potential in advanced lines, cluster mean of the
traits must be taken into deliberation. Accordingly, the cluster I might be deliberately
selected to improve yield potential in the advanced lines. The simultaneous consideration
character association both at genotypic and phenotypic levels and genetic and genetic
diversity fertile grains per panicle, panicle weight and 1000-grain weight along with the
advanced line, PL6 may be included in further breeding to evolve super quality fine rice
varieties suitable for our country. | en_US |
