Morphological and molecular characterization of fifteen Bangladesh and Philippine traditional rice (Oryza sativa L.) varieties for salt tolerance at reproductive stage.

Date

4-2013

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Duka, Marcelo A.

Abstract

The salt tolerance of 15 native rice varieties from Bangladesh (7) and the Philippines (8) at the reproductive stage was determined to obtain new sources of salinity tolerance for rice breeding programs. Screening for tolerance at seedling stage was first studied to conform the results of a previous study by Aala in 2012. The results of the studies were were different but the discrepancies may be attributed to some differences in the screening methods and the time of rating injury symptoms. However, the results of Aala (2012) and this study consistently show that Na/K ratio is a good indicator of salt tolerance. The tolerance at the reproductive stage was then determined. Morphological, biomass and yield data were observed. The sensitive check, IR29, was not able to survive under saline condition. n general, Bangladesh lines performed poorly while most of the Philippine lines also performed poorly. This is specially true for Philippine lines closely related with IR29 and FL478 (IR64856-38-178-1-1). Reppeng, a traditional variety from the Philippines, had the highest yield under saline conditions with an average total rain weight of 8.98 grams (610.5 seeds). Molecular data for 32 markers obtained with permission from Aala (2012) and for 3 markers from the International Rice Research Institute were used in molecular characterization of the 15 varieties from Bangladesh and the Philippines. A total of 90 alleles were detected by the 35 markers. Three markers (AP3206f, RM1287, RM127) were able to detect heterozygotes and nine markers (RM3843, RM3412b, RM7075, RM20224, RM413, RM493, RM10764, and RM144) had a high PIC value indicating higher marker strength. A dendogram was constructed based on the molecular data. Two distinc clusters were formed, Cluster 1 consisted two Bangladesh lines while Cluster 2 consisted of the remaining 13 accessions, IR29 and FL478. Within Cluster 2, the remaining Bangladesh lines formed a separate subcluster. Six Philippine traditional varieties clustered together with FL478 and IR29. Reppeng formed a single branch indicating that this variety may have tolerance mechanisms that the other varieties do not have. Thus, it may be potential novel source of salinity tolerance traits.

Language

English

Location

UPLB Main Library Special Collections Section

Call Number

Thesis

Document Type

Thesis

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