Luffa acutangula and L . aegyptiaca are two vegetable species commonly found in South and South East Asia. L . acutangula is widely grown; however, L . aegyptiaca is considered as an underutilized crop. The species delimits, phylogenetic positions, and the varietal identities of L . acutangula and L . aegyptiaca in Sri Lanka are not known. Thus, in the present study, we aimed to establish the species delimits and varietal identities of L . acutangula and L . aegyptiaca varieties grown in Sri Lanka using morphometric, phylogenetic and organoleptic assessments. We assessed five varieties of L . acutangula and three varieties of L . aegyptiaca . The vegetative and reproductive data were collected for the morphometric analysis and DNA sequence polymorphism of the makers rbcL , trnH-psbA and ITS for the phylogenetic analysis. We also conducted an organoleptic assessment based on taste parameters; aroma, bitterness, color, texture, and overall preference using the dishes prepared according to the most common Sri Lankan recipe for Luffa . The variation of the vegetative and reproductive traits grouped L . acutangula varieties into two distinct clusters. The trnH-psbA polymorphism provided the basis for the species delimits of L . acutangula and L . aegyptiaca . The rbcL and ITS polymorphisms provided the basis for the identities of the varieties of L . aegyptiaca and L . acutangula respectively. In the phylogeny, the L . acutangula varieties of Sri Lanka formed a unique clade and the L . aegyptiaca varieties formed a reciprocal monophyletic group in comparison to worldwide L . aegyptiaca reported. The taste parameters aroma, texture, color, and overall preference were significantly different among the Luffa varieties. The L . aegyptiaca varieties received lower preference in the organoleptic assessment. The present study sets the species delimits, phylogenetic positions and the varietal identities of the cultivated germplasm of Luffa and revealed the distinct morphological and organolep...

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Purpose: Gliricidia sepium is a wide spread multipurpose legume plant which is effective in nitrogen fixation and host to many Rhizobial strains. However, few studies have been carried out to identify and characterize the Rhizobial populations inhabiting G. sepium in Sri Lanka. The main objective of this study was to isolate and identify the stress tolerant Rhizobial strains in G. sepium. Research Method: Root nodules of G. sepium were collected from seven locations in Ampara district, which belongs to dry zone in Sri Lanka. Total of 35 isolates were screened for the tolerance for different pH, salinity, drought conditions and temperatures separately as well as in combinations. Genetic diversity of stress tolerant isolates was assessed using ERIC fingerprinting. Findings: All isolates were grown under wide range of stress conditions. The Rhizobial strains isolated from the site closer to the coast showed a high tolerance for all salinity levels as they are adapted to the high salt stress experienced in their natural habitat. The growth response to drought conditions and temperature was variable. Moreover, 14 isolates showed a high tolerance for more than two extreme stress conditions. When extreme conditions were combined, 12 isolates among 14 were survived. These 14 isolates grouped in to ten clusters at 69% similarity coefficient that make them genetically diverse. Research Limitation: The stress tolerance was observed under laboratory conditions and it does not provide enough evidence for the effectiveness of selected isolates in field. Original Value: The 14 stress tolerant Rhizobial isolates can be used to cross inoculate crop legumes to identify possible cross inoculation groups in order to reduce nitrogen fertilizer usage.

The family Solanaceae is composed of a broad list of species, which includes both commercial and wild accessions with enormous medicinal importance. The published phylogenies on Sri Lankan wild and naturalized Solanum spp. confers that S. hispidum, and S. torvum are sister species. However, this has not been proved using multiple barcoding markers. Moreover, S. torvum, an underutilized crop is expected to contain multiple varieties. However, varietal descriptions using morphological and DNA markers have not been done so far. Therefore, our study was aimed at accurate identification of four Solanum spp. found in Sri Lanka (S. torvum 'Bindu' and landraces S. hispidum and S. pubescens) using chloroplast marker based DNA barcoding combined with a morphological description. We used 29 quantitative and 22 qualitative parameters, comprised of vegetative and reproductive traits along with eight DNA barcoding markers. We sequenced rbcL and trnL-F to check the DNA polymorphisms. According to the combined morphological analysis of reproductive and vegetative parameters, the four species clustered separately. There were no separation observed between S. torvum and S. hispidum. Solanum pubescens diverged out and cladded with old world nightshades in molecular analysis. These results are in line with published literature and validates that trnL-trnF could be used as a potential marker to carry out a combined DNA barcoding analysis with matK. However, trnL-trnF could not be used to discriminate between S. torvum and S. hispidum species.

The symbiotic association between Rhizobium and leguminous species plays a significant role in sustainable agricultural systems as it contributes higher amounts of fixed nitrogen to soil through biological nitrogen fixation. Gliricidia sepium is one of the most commonly cultivated agro forestry trees in the world. This leguminous tree is widely distributed throughout Sri Lanka. A very limited number of studies are available on G. sepium-Rhizobium symbiosis in Sri Lanka. The main objective of this study is to isolate and identify the stress tolerant Rhizobium sp. in G. sepium as a preliminary approach to use rhizobial strains for cross inoculation of crop legumes in order to minimize the heavy use of chemical nitrogen fertilizers. The root nodules of G. sepium were collected from seven sites in Anuradhapura district which is located in the dry zone of Sri Lanka. A total of 34 strains were tested for their tolerance to different physiological conditions namely pH, salinity, drought and temperature. Fifteen strains showed a higher tolerance among the isolated 34 strains when grown under a wide range of physiological conditions. When these 15 stress tolerant rhizobial strains were grown under extreme physiological conditions, 12 strains could survive well as they often experience adverse environmental conditions in their natural habitat. DNA fingerprinting analysis with ERIC 1R and ERIC 2R showed that the 15 strains are genetically diverse and they belong to 9 clusters at 71% similarity level.