Morpho-physiological screening of rice (Oryza sativa L.) genotypes for salinity tolerance

Date

10-2007

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Maribel L. Dionisio-Sese

Abstract

This study aims to evaluate rice genotypes for morpho-physiological traits contributing. to salinity tolerance. Sixteen rice genotypes were subjected to salinization with 12 dS ft during the seedling stage. Vigor was measured 14 days after immersion in nutrient solution whereas growth. sodium and potassium content were obtained 10 and 25 days after salinization. Visual evaluation of salinity stress symptoms based on modified standard evaluation system (SFS) as %%ell as leaf chlorophyll content were measured 25 days after salinization. Varietal differences were found to exist in the rice genotypes. Prior to salinization, Pokkali followed by Cheriviruppu exhibited the two highest vigor scores, and 1R29 and CSR II the two lowest. Ratings of salinity stress symptoms ranked Pokkali, FL478 and 1R651 as tolerant varieties and 11229. CSR 11 and Kalimekri as susceptible varieties. Salinity generally caused suppression of growth in terms of root and shoot weights which was evident in 1R29. CSR II and 1R74. Highest accumulation of sodium ions both in roots and shoots was observed in 11229 whereas Pokkali. FI.478. 1R651. Cheriviruppu and 1124630 maintained low shoot sodium concentrations. Shoot Na/K ratio was also observed to be highest in 11229 and lowest in Pokkali and Cheriviruppu. Shoot sodium concentrations, in turn, may have resulted in the observed low and high leaf chlorophyll contents in 11229 and Pokkali. respectively. Correlation analysis of the morpho-physiological characters studied indicates that both vigor and SETS morphologically. and shoot sodium concentration or shoot Na/K ratio and total chlorophyll content physiologically are good characters in evaluating rice genotypes for tolerance to salinity..

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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