Characterization of traditional rice (Oryza sativa L.) varieties using grain mineral density (GMD), microsatellite markers, morphoagronomic and grain physico-chemical parameters.

Date

10-2001

Degree

Bachelor of Science in Biology

Major Course

Major in Ecology Genetics

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Adelina A. Barrion

Abstract

A study was done to characterize selected traditional rice germplasm based on its grain mineral density (GMD), molecular characteristics, as well as morphoagronomic and grain physico-chemical traits and establish genetic relationships among these varieties, with an emphasis on their GMD. Forty-six varieties (including 38 Philippine traditional rices) were planted in both field and greenhouse conditions. DNA was extracted from leaf tissue and subjected to PCR amplification using 14 microsatellite primers and run in 5% acrylamide gels. Marker data were then input into NTSys for genotypic diversity analysis. Harvested grains were analyzed for mineral content for the elements iron, zinc, phosphorus, calcium, magnesium, manganese, potassium, sodium, copper, sulfur, molybdenum and boron via Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The varieties were also evaluated for six morphoagronomic and six grain physicochemical characteristics. Of the 37 varieties that were finally included in the study (with 29 Philippine traditional rice varieties) GMD levels showed that most traditional varieties had higher mean iron, zinc, calcium, boron, sodium, potassium, phosphorus and sulfur than commercial varieties/ breeding lines but have but have moderate levels of iron, calcium magnesium, potassium and phosphorus, though individual varieties have unique variations in grain mineral density. The highest positive correlation between minerals was for magnesium and potassium, as well as magnesium and phosphorus (both are 90% correlated). Negative correlations were also present at lower degrees. Marker data generated a dendrogram having two clusters but the small number of markers used resulted into ambiguous clustering of the two varieties, as some indicas were clustered along with japonicas and vice versa. There was also no observed relationship between GMD and the clusters produced by marker data. The traditional varieties were of intermediate to tall types (110- >130 cm), late maturing (124-137 DAS) with well exserted panicles were also a trait common to the traditional varieties studied. Phenotypic acceptability of the varieties was mostly fair to good. The varieties had intermediate grain length and of medium grain shape and mostly had white seed coats. Also, a majority of the varieties had a soft gel consistency, with intermediate amylose content and intermediate gelatinization temperature. Morphoagronomic and grain physicochemical characteristics show considerable among traditional varieties especially those native to Philippines. Preliminary GMD data show varieties to have very high levels of mineral elements, as well as moderately extensive variation, some of which have potential as parents for breeding programs involving improved mineral content in rice.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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