Raj, Devaki , Govindaraju, Diddahally .
Path Analysis of Developmental Variation of Phenotypic Components among Pitch Pine (Pinus rigida Mill.) Families from the Walden Woods.
Path analysis was employed to investigate the magnitude of developmental variation among six quantitative characters in thirty-five pitch pine families from the Walden Woods, Lincoln, MA. The seedlings were grown for six months in two environments: sand (poor) and loam (better) with four replications under green house conditions. Data were recorded on stem height and weight, crown height and weight, total height and weight. Data were analyzed using analysis of variance, heritability and path analysis. Path analysis measures both direct and indirect effects of independent variables on dependent variables through intermediary variables. Hence, it is a powerful approach for evaluating the causal flow of physiological variables among a system of morphological characters during growth and development. Significant genotype-environment interaction was found for most characters. Heritability for four characters was greater for families raised in sand than in loam. Path analysis suggested that the physiological resources may be channeled differentially among various quantitative characters in relation to their environments. Environment modulates not only the development of individual phenotypic or morphological components but also their relationship to the entire organism. Occasionally, however, environmental effects may overwhelm the genetic expression of a given quantitative trait. Thus context dependent expression of genetic variation may be common to most quantitative traits. Knowledge of relative flexibility/plasticity of individual characters in relation to specific environmental resources may be useful toward understanding developmental biology, growth and reproduction in plants.
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1 - 4 Marshall Road, Lexington, Massachusetts, 02420, USA
Pitch pine, Development, Heritability.
Presentation Type: Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM