GENETIC ANALYSIS FOR GROWTH AND OLEORESIN TRAITS OF CHIR PINE (Pinus roxburghii Sargent)
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Date
2015
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Abstract
ABSTRACT
The present investigations entitled “Genetic Analysis for Growth and Oleoresin Traits of Chir
pine (Pinus roxburghii Sargent)” were carried out in the Research field and Laboratory of the
Department of Tree Improvement and Genetic Resources, College of Forestry, Dr YSP University of
Horticulture and Forestry, Nauni, Solan (HP) during the year 2010-2012, to: 1) evaluate different
growth traits (height, diameter at breast height, bark thickness, crown height and crown length),
needle characteristics (colour, length, thickness and number of stomata per mm of row), wood traits
(moisture content, specific gravity and tracheid length) of different half sib chir pine progenies; 2) to
carry out molecular characterization through RAPD, ISSR and SSR markers, and, 3) to carry out
marker trait association for the aforesaid traits, besides the oleoresin yield of the different genotypes.
All the traits varied significantly, with mean values height (18.08 m), diameter at breast height
(34.76 cm), bark thickness (2.73 cm), crown height (7.80 m), crown length (10.38 m), needle length
(20.78 cm), thickness (0.61 mm), number of stomata per mm of a row (9.71), wood moisture content
(54.31%), specific gravity (0.41) and tracheid length (1.68 mm). Variability estimates, genetic
parameters, correlation studies, principal component analysis and divergence studies exhibited high
variability among all the half sib progenies. Characters which exhibited high heritability like crown
height (H2=0.45), wood specific gravity (H2=0.66), needle thickness (H2=0.48), followed by higher
genetic gain show additive genetic variation and can be exploited quiet well in advanced breeding
programs, thus more effective in selecting the best genotypes for a trait. Genetic divergence was
studied through cluster analysis and dendrograms. Molecular characterization through RAPD, ISSR
and SSR revealed high polymorphism percentage (90.14, 94.84 and 100, respectively); with
respective band size ranges 105-1490 bp, 198-2015 bp and 103-239 bp. Dendrogram based on these
markers, individually as well as combined, were made for diversity analysis. Structural analysis was
carried out for the population diversity studies, and for association mapping. Three clusters resulted
for each marker, beside some genotypes as admixtures. Association mapping with different traits
revealed 12 associations with RAPD markers, 6 associations with ISSR markers, 8 associations with
SSR markers at P value (<0.05). Coefficient of determination, R2 value, ranged from 0.0757 for
UBC841 with wood specific gravity to 0.1495 for NAD3-1 with crown length.
Description
Keywords
genetics, genotypes, wood, biological phenomena, polymorphism, biological development, rapd, selection, phenotypes, yields, Chir pine (Pinus roxburghii Sargent), Genetic Analysis