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.

Essential oil composition of Aegle marmelos (L.) Correa: chemotypic and seasonal variations.

BACKGROUND: Aegle marmelos (L.) Correa is a sacred medicinal and nutraceutical tree of India. The present study planned to explore the chemotypic and seasonal variability of the leaf essential oil of A. marmelos from north India for proper industrial utilization. RESULTS: The essential oil yield varied from 0.37% to 0.80% in leaves of A. marmelos populations. Analysis of the essential oils by gas chromatography and gas chromatography-mass spectrometry, and the subsequent classification by statistical analysis showed three types of chemical compositions for A. marmelos with significant variations in their terpenoid compositions. Major components of the essential oils were limonene (31.0-90.3%), α-phellandrene (<0.05-43.5%), (E)-ß-ocimene (0.7-7.9%), α-pinene (<0.05-7.5%), (E)-caryophyllene (0.5-5.3%), ß-elemene (<0.05-4.2%) and germacrene B (0.0-3.3%). In addition to this, essential oil of a locally growing A. marmelos population was also investigated for seasonal variations. The essential oil yield in this population varied from 0.37% to 0.82% during different seasons. Major constituents, namely α-phellandrene (35.8-49.8%), limonene (24.7-34.3%), (E)-ß-ocimene (4.2-10.0%) and α-pinene (6.0-8.0%), showed considerable variations due to season of collection. CONCLUSIONS: The growing location and harvesting season had a close relation to yield and quality of A. marmelos leaf essential oil. The results obtained are of significance for determining a suitable time for harvesting A. marmelos leaves.