Bael (Aegle marmelos L. Corrêa) is an economically valuable tree species in South Asia. The ripen bael fruits are popular among people because of the delicious fruit pulp, which is ideal for making jam, syrup, and pudding. Bael possesses many medicinal values and therefore used as an ingredient in ayurvedic herbal medical preparations. The fruits, bark, leaves, seeds, and roots of bael contain bioactive compounds such as coumarin, xanthotoxol, imperatorin, aegeline, and marmeline. These compounds can provide antidiabetic, anticancerous, antifertility, antimicrobial, immunogenic, and insecticidal activities. Bael is also essential as a species for reforestation, especially in the unfertile marginal lands. Bael seeds possess a unique fatty acid (12-hydroxyoctadec-cis-9-enoic acid or ricinoleic acid), a convertible item into biodiesel. Bael is an underutilized fruit species in South Asian countries. However, numerous studies report the medically significant properties and industrially vital characteristics of bael in India. The present review focused on summarizing and discussing the essential details and potentials of bael for industrial applications towards economic development.

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.

Bael (Aegle marmelos (L.) Corr.) is a medicinal fruit tree species belongs to the family Rutaceae grown in South Asian countries including India, Sri Lanka and Bangladesh. It is an underutilized fruit species in Sri Lanka, although it has food as well as medicinal value with a good economic potential. Popularizing bael as a profitable cash crop is often hindered by the limited availability of high quality planting material. In Sri Lanka, five elite bael accessions namely Beheth Beli, Paragammana, Mawanella, Rambukkana and Polonnaruwa Supun have been identified and used for mass propagation through budding and grafting. But this effort is often hampered by many limitations faced in large scale production. Micropropagation is an alternative technique to produce clonal plants in large scale. However, the complex phenological behaviour of the bael trees could affect its success. Therefore, the present study was undertaken to identify the correct phenological stage of bael trees to collect explants for the micropropagation. Leaves and twig explants were collected for micropropagation from five elite bael accessions during the period of July, 2016 to June, 2017 on monthly basis to capture the best phenological stage. The Beheth Beli tree and grafted plants of other four accessions were established at the Fruit Crop Research and Development Institute, Department of Agriculture, Sri Lanka. The surface sterilized explants were established on Murashige and Skoog medium supplemented with 1 mg/L of 6-Benzylaminopurine, 3% sucrose, solidified with phytogel. A successful organogenesis was only observed in explants collected in the months of April, May and June (39 to 68 %) where there was no significant difference in success was observed between the leaf and twig explants (P>0.05). However, grafted bael accessions exhibited a significantly different mean success percentage in organogenesis where Paragammana and Rambukkana accessions showed a high success for leaf explants and Mawanella and Rambukkana accessions showed a high success for twig explants. These results could be readily employed to multiply the elite bael accessions in Sri Lanka.

Abstract:The genetic studies of tropical tree species containing high amount of phenols are greatly hampered by the inability to extract sufficient quantities of high quality DNA and the presence of PCR inhibitors in extracted DNA samples. While there are some DNA extraction and PCR protocols for such species, no consistency in results. Hence, optimization of such protocols is a prerequisite for conducting research studies on tropical flora. This study reports the optimization of cheaper DNA extraction and PCR procedures for plants having high amount of phenolic compounds and PCR inhibitors. Three fruit crop species, Bael (Aegle marmelos L. Correa), Pomegranate (Punica granatum L.) and Mango (Mangifera indica L.), with distinctly diverse secondary metabolic profiles, were used as examples. The CTAB DNA extraction method, with some modifications, was compared with two commercially available DNA extraction kits namely; Promega Wizard® Genomic DNA purification kit and QIAGEN DNeasy® Plant Mini kit. DNA from three to five genotypes from each species was extracted from each method and the quality and quantity were assessed. Spermidine was added to the PCR mix at the rate of 0.8 µM to block the PCR inhibitors and the DNA samples were amplified using universal plant barcoding primer pair rbcL, and SSR or ISSR primers. The modified CTAB method resulted significantly higher quantity of quality DNA in all samples compared to two commercial kits. Henceforth DNA extracted from CTAB method, and the two commercial kits were used to precede PCR. However, expected bands were not generated in regular PCR. Interestingly, the inclusion of spermidine amplified the relevant band/s in relatively easy PCR reactions such as rbcL, as well as trickier reactions such as SSR and ISSR. These results suggest that cheaper alternative procedures used in this research study could be used successfully for the range of applications in plants with array of secondary metabolic profiles.

Tomato (Solanum lycopersicum L.) is a commonly grown vegetable crop in