Genetic variability and multivariate analyses of floral traits related to outcrossing in rice (Oryza sativa L.)

Date

6-2016

Degree

Bachelor of Science in Agriculture

Major Course

Major in Agronomy

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Jose E. Hernandez

Restrictions

Restricted: Not available to the general public. Access is available only after consultation with author/thesis adviser and only to those bound by the confidentiality agreement.

Abstract

A detailed morphological characterization of 16 outcrossing-related floral traits on 70 cultivated rice parental lines was conducted in the screenhouse at Bayer CropScience, Calauan, Laguna. The study is aimed at estimating the genetic parameters that can provide information towards floral trait improvement and determining the association among the floral traits and the floral trait profiles of a set of rice parental lines through principal component analysis (PCA). Stigma size (STGS), style length (STYL), total stigma exsertion rate (TSER), single stigma exsertion rate (SSER) and double stigma exsertion rate (DSER) showed high genetic advance as percentage of mean (%GA) coupled with high heritability (H²), which implies that considerable improvement could be achieved in these traits by simple phenotypic selection. Stigma width (STGW) and pollen count per anther (POLC) had high H² but moderate %GA. The lowest H2 came with pollen diameter (POLD), followed by stigma length (STGL) and style + stigma length (SSTL), which emphasizes the significant role of the environment in their inheritance. High H² coupled with low %GA was noted for anther length (ANTL), spikelet length (SPKL), spikelet width (SPKW) and spikelet shape (SPKS), indicating non-additive gene action. Results of phenotypic correlation analysis show that TSER was positively and significantly correlated with SSTL (0.67) and SPKL (0.84). Significant positive correlation between POLC and ANTL (0.96) was also obtained. TSER and POLC are based on tedious count data gathering, hence, prediction equations for these parameters through simple and multiple linear regression analyses are hereby proposed. PCA involving 10 floral parameters resulted in three principal components (PC1, PC2 and PC3) that accounted for 85% of total data variability, with the first two having the cumulative contribution of 72%. PC1 and PC2 were used to generate the score (samples) and loading (variables) plots. The plots showed the distinct aggregation of stamen traits POLC and ANTL as well as the pistil traits STGL, STYL, SPKL, SPKS and TSER. Correspondingly the association of samples according to the variable patterns was revealed, which could allow identification of superior rice lines for the parameters of interest. Overall, this study revealed valuable genetic information and data patterns toward selection of useful genotypes and improvement of outcrossing-related floral traits in rice through breeding and selection.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2016 A3 /D45

Document Type

Thesis

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