Biology subjects

Bandaranayake, P. C. G.

Publications and source records attributed to Bandaranayake, P. C. G..

2 recordsLinked to original sources

bioRxiv2022

Macroscopic and microscopic study on floral biology and pollination of Cinnamomum verum Blume (Sri Lankan)

Cinnamomum verum Blume (syn Cinnamomum zeylanicum) commonly known as Ceylon cinnamon, has gained worldwide attention and well supported by experimental data. Maintaining the yield quality and quantity are essential, especially for high-end value-added products. Breeding superior varieties and producing good quality planting materials are critical for commercial cultivation efforts. However, limited literature is available on the floral development and biology of C. verum. We assessed the seasonal flowering, floral development and pollination of type A and type B varieties of C. verum. Both macroscopic and microscopic data were collected on floral biology, pollination, male and female floral organs before and after pollination. Cinnamomum verum is morpho-anatomically, structurally, and physiologically adapted for cross-pollination, possible between the two cultivars; type A (Sri Gemunu) and type B (Sri Wijaya) flowers; naturally evolved with Protogynous Dichogamy. It possesses a dry stigma, which changes its surface characteristics after pollination. During close-pollination, a higher percentage of pollen shrink and shrivel on stigma while it develops callose plugs to obstruct the growth of the pollen tube. However, during changes in environmental conditions, female and male stages in the same tree overlap for about 45-60 min suggesting possible close-pollination within the same plant. Moreover, 4-8% of the flowers formed fruits after natural close and hand pollination. pollen was found fully hydrated even after close-pollination. Although C. verum is adapted for cross-pollination, natural close-pollination is also possible. The data suggest the complex nature of the sexual reproduction of C. verum. Well-managed breeding attempts will develop superior C. verum varieties.

plant biology↗

bioRxiv2022

A unique single nucleotide polymorphism in Agouti Signalling Protein (ASIP) gene changes coat colour of Sri Lankan Leopard (Panthera pardus kotiya) to dark black

The Sri Lankan Leopard (Panthera pardus kotiya) is an endangered subspecies restricted to isolated and fragmented populations in Sri Lanka. Among them, the melanistic leopards have been recorded on rare occasions. The existing literature suggests that melanism evolved several times in the Felidae family, with three separate species revealing distinct mutations. Nevertheless, the mutations in the remaining species, including Sri Lankan black leopard, are unknown. We used reference-based assembled the nuclear genomes of Sri Lankan normal and black leopard and de novo assembled mitogenomes of the same to investigate the genetic basis, adaptive significance, and evolutionary history of the Sri Lankan black leopard. Our data suggested coalescence time of Sri Lankan regular and black leopards at [~]0.5 Million years, sisters to Panthera pardus lineage. Interestingly, in the black leopard, a single nucleotide polymorphism in exon-4 possibly completely ablates Agouti Signaling Protein (ASIP) function. Existing genomic data suggest new a species-specific mutation of the ASIP gene in the Felidae family, contributing to naturally occurring colouration polymorphism. As such, the Sri Lankan black leopard and normal leopard probably evolved from the same ancestor, while the mutation in the ASIP gene resulted in black coat colour. This rare mutation could be adaptable to the environment that back leopards reported, camouflage, with a likelihood of recurrence and transmission to future generations. However, protecting this sensitive environment is critical for the conservation of the existing populations and providing breeding grounds.

genomics↗