Underutilized wild Dioscorea Species Found in the Dry Zone Forests of Sri Lanka

Wild germplasm of Dioscorea aculata (syn. Dioscorea pentaphyla) known as Katuala andDioscorea obcuniata known as Hiritala were explored, investigated and characterized from forests of Anuradhapura, Polonnaruwa and Hambantota areas. These species grew vigorously in dry, sandy and stony areas. They were field planted at Aralaganwila and evaluated the performance. Katuala and Hiritala species produced aerial auxiliary bulbils that dispersed naturally. Tubers and aerial bulbils of Katuala were suitable for propagation. Tubers exhibited dormancy for about 5 months and another 5 months from planting to harvesting. Both species produced yams once a year. Planted tubers produced vigorously growing vines and then female flowers and bulbils in about 2 months and male flowers in about 2.5 months. Planted bulbils produced slow growing vines but no flowers, bulbils or under ground tubers in 5 month period. Cultivated germplasm produced bulbils (0.4-0.9 g) along the main stem and lateral stems at about 12-46 cm above the ground level. Katuala and Hiritala species possessed a spiny stem. Succulent aerial parts died off but tubers remained dormant during dry season in yala. They produced shoots with the onset of rains in maha. Characteristic differences of growth and morphology of aerial parts and tubers are given. Tubers of Hiritala species were edible in fresh form and that of both species were cooked and consumed. Dioscorea species inhabited in Sri Lanka are in danger due to urbanization, habitat destructions, unsustainable harvesting, damage by wild animals and lack of protection, replanting or cultivations programs

Local Fractal Dimensions and Multifractal Analysis of the Root System of Legumes

The fractal dimension (D) is the main concept of fractal geometry. D may have the potential to describe morphology in overall terms for root systems quantitatively. However, it is often difficult to discriminate root systems possessing a common D but having a different morphological appearance. We tested the potentiality of multifractal analysis as a tool for characterizing the morphology and architecture of root systems, and applied this method for discrimination of such root systems having similar Ds. We adopted mass fractal measure and determined Ds for small area (local fractal dimension, DLocal) at different locations of root systems. The multifractal spectrum indicated that Dlocal varied with the location on the roots, suggesting that root systems possess a multifractal structure, the complexity is unevenly distributed, and its characteristic can be partly described with the Dlocal spectrum. The skewness and kurtosis of histogram of Dlocal varied among species, even when they possess root systems with a common D which was determined by the box-counting method as an overall morphology of the system (global D). The spectrum of Dlocal was further analyzed in relation to topological parameters. We found significant correlation between topological index and skewness as well as between topological index and kurtosis. These suggest that the variation of Dlocal spectrum can be an indication of variability of architecture in a locally restricted area of root system. The multifractal analysis can be applicable and it has a potential for discriminating and characterizing root systems having a common global D, but with different morphology

Assessment of the elite accessions of bael [Aegle marmelos (L.) Corr.] in Sri Lanka based on morphometric, organoleptic, and elemental properties of the fruits and phylogenetic relationships.

Aegle marmelos L. (Bael) is a native tree fruit species in the Indian subcontinent and Southeast Asia. Bael is a popular fruit because of its significant nutritional and medicinal properties. However, bael is an underutilized fruit species in Sri Lanka. Thus, Fruit Crop Research and Development Station of the Department of Agriculture of Sri Lanka has selected five elite bael accessions (Beheth Beli, Paragammana, Mawanella, Rambukkana, and Polonnaruwa-Supun). We assessed these five accessions for the variation of the fruit size, pulp, organoleptic preference, elemental properties, genetic diversity, and evolutionary history. The fruits at the golden-ripe stage were collected during the peak fruiting seasons in 2015, 2016, and 2017. The fruit size, pulp, shell thickness, and seed size were measured and subjected to the General Linear Model (GLM) and Principal Component (PC) Analyses. The fruit pulp was distributed among a group of 30 taste-panelists to rank for the parameters: external appearance, flesh color, aroma, texture, sweetness, and overall preference. The rank data were subjected to association and PC analyses. The elemental contents of the fruit pulp samples were measured using Inductively coupled plasma mass spectrometry and subjected to GLM and PC analyses. We observed a significant diversity in fruit size, organoleptic preference, and elemental contents among bael accessions. Rambukkana and Polonnaruwa-Supun yield the biggest and most preferred fruits. We used trnH-psbA, atpB-rbcL spacer, matk-trnT spacer, and trnL markers to construct phylogenies. Sri Lankan bael split from an Indian counterpart, approximately 8.52 MYA in the Pliocene epoch. However, broader germplasm of Indian bael must be assessed to see the presence of any independent evolution within Sri Lanka