Temporal tillering behavior of Sri Lankan elite rice varieties in response to phosphorus availability

As rice is the staple food of most Asian countries, rice straw has become one of the largest agricultural wastes in Asia. It has not been subjected to adequate value additions yet. However, it has excellent potential to be converted to valuable materials, as it contains a significant amount of cellulose. Therefore, it would be beneficial in many ways to identify the cellulose yields of straws of different rice varieties. In general, the cellulose content of biomass is determined by wet chemical methods. Though these methods are accurate, they are not convenient to use under industrial conditions. This research work focuses on investigating the potential of thermal analysis as an alternative way to predict cellulose yields. For the study, rice straws of most frequently cultivated traditional Sri Lankan rice varieties: Suwandel and Raththal, as well as technically modified Sri Lankan rice varieties: BG300 and BG352, were selected. The results obtained by the proposed method were validated by an established three-step chemical extraction process.

Download Full-text

Morphological diversity of Sri Lankan traditional rice varieties “Pachchaperumal” and “Suduru samba”

Open Agriculture ◽

10.1515/opag-2017-0058 ◽

2017 ◽

Vol 2 (1) ◽

Author(s):

Elpitiya Udari Uvindhya Rathnathunga ◽

Sudarshanee Geekiyanage

Keyword(s):

Yield Components ◽

Growth Parameters ◽

Morphological Diversity ◽

Hierarchical Cluster ◽

Morphological Characters ◽

Sri Lankan ◽

Rice Varieties ◽

Grain Width ◽

Positive Correlations ◽

Traditional Rice

AbstractSri Lankan traditional rice varieties consist of more than one accession mostly which, exhibit a wide variation in morphological characters, flowering time and yield. The objective of this study was to evaluate the diversity based on days to flowering (DF) and 12 morphological characters of two Sri Lankan traditional rice varieties Pachchaperumal and Suduru samba comprising of 13 and 7 accessions respectively. DF of Pachchaperumal and Suduru samba varied from 60 - 72 and 79 - 99 days respectively. Vegetative morphological characters and yield components also varied among Pachchaperumal and Suduru samba accessions while pericarp colour, grain width, and length were distinct characters between the two varieties. According to the hierarchical cluster analysis, 2 major clusters were identified at the rescale distance of 25 separating accessions of Pachchaperumal and Suduru samba except for accession 3136 of Pachchaperumal, which was located in Sudura samba cluster. Seven clusters were derived at rescaled distance of 5 where accessions of similar quantitative and qualitative morphological characters were clustered together. There were negative correlations between DF and selected yield components in contrast to positive correlations between DF and selected vegetative growth parameters. Our results may be useful in the determination of identity of accessions belonging to the same variety, which could be further supported by molecular analysis.

Download Full-text

Development of a core collection from Sri Lankan traditional rice (Oryza sativa) varieties for phenotypic and genetic diversity

Nusantara Bioscience ◽

10.13057/nusbiosci/n130109 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Shyama Weerakoon ◽

Seneviratne Somaratne

Keyword(s):

Genetic Diversity ◽

Oryza Sativa ◽

Sri Lanka ◽

Core Collection ◽

Morphological Characters ◽

Morphological Features ◽

Sri Lankan ◽

Rice Varieties ◽

Traditional Rice ◽

Phenotypic And Genetic Diversity

Abstract. Weerakoon SR, Somaratne S. 2021. Development of a core collection from Sri Lankan traditional rice (Oryza sativa) varieties for phenotypic and genetic diversity. Nusantara Bioscience 13: 61-67. A collection of over 2000 traditional rice varieties are conserved at Gene Bank, Plant Genetics Resource Center, Sri Lanka. Oryza sativa varieties grown in Sri Lanka from ancient times to the middle of the last century are known as traditional rice. These varieties show adaptability to biotic and abiotic stresses and, an important component of biodiversity of Sri Lanka. A detailed understanding of the diversity of traditional rice varieties is essential for effective utilization of rice genetic resources and identification of potential parents possessing valuable genetic traits for future crop improvement. Study objectives were phenotypic and molecular characterization of one-hundred traditional rice varieties and to identify a core collection for phenotypic and genetic diversity. Rice varieties were grown in a plant house following RCBD with 4 replicates and 5 plants per replicate. Thirty-two agro-morphological characters were observed/collected. Genomic DNA was extracted from 20-days-old seedlings. Thirty?three microsatellite (Simple Sequence Repeat-SSR) primer pairs were used to assay genetic variation and PCR products were subjected to fragment analysis by capillary electrophoresis. Descriptive statistics and basic inferential statistical analyses were performed to access variation of agro-morphological characters among rice varieties. Cluster analysis and Multidimensional scaling produced 07 groups which were further analyzed using Classification and Regression Analysis to extract the diagnostic agro-morphological features. Groups of rice varieties were characterized by lemma palea color, awn color at maturity, seedling height, and flag-leaf angle. Traditional varieties represent distant clusters on agro-morphological features. Molecular analyses revealed all 33 loci displayed polymorphism (66.7-96.9%) among 100 traditional rice varieties with a total of 387 alleles identified with an average of 11.72 alleles per variety. All varieties were genetically structured into fifteen well-separated groups. UPGMA analysis based on Jaccard's similarity separated varieties into 05 major clusters. Genetic diversity information is useful in the efficient use of Sri Lankan rice germplasm and managing in situ and ex situ germplasm collections in conserving traditional rice varieties.

Download Full-text