Journal of Threatened Taxa | www.threatenedtaxa.org | 26 July 2021 | 13(8): 19189–19190
ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)
#6218 | Received 24 May 2020 | Final received 07 July 2021 | Finally accepted 09 July 2021
Occurrence of vivipary in Ophiorrhiza rugosa Wall. (Rubiaceae)
Birina Bhuyan 1 & Sanjib Baruah 2
1,2 Department of Botany, Bodoland University, Kokrajhar, Assam 783370, India.
1 firstname.lastname@example.org, 2 email@example.com (corresponding author)
Ophiorrhiza rugosa Wall. (Family Rubiaceae), a highly valuable medicinal herb and a potential source of Campothecin (CPT) used as an anticancer alkaloid producing plant (Gharpure et al. 2010). There are many natural varieties of O. rugosa Wall., which are now considered as strong candidates for the CPT (Hsiang et al. 1985; Vineesh et al. 2007).
Vivipary is the process-by which seeds germinate within the fruits followed by embryo development before the seeds are dispersed from the parent plant. Vivipary has been considered as a precocious germination, relatively unusual phenomenon in angiosperms (Farnsworth 2000).
Here, we report an unusual occurrence of the viviparous germination of seeds of Ophiorrhiza rugosa in the wild. This rare phenomenon was observed during the field visit to Karbi Anglong District, Assam in the last week of May 2019. The sites were located in 25.9540N and 92.6030E, at 128m. The rainy season in this area is with 90% of the rainfall during April–June (60–70 days). On an average, the area receives 1,400–2,000 mm of rainfall; and the soil is clayey loam.
The authors observed an occurrence of the true viviparous germination in the plant growing on hill slopes (Image 1). The plant is fully grown and contains the mature capsules. The capsules of the plant contain two halves and the seedlings were growing within the halves. The germination of seeds was epigeal and one capsule contains an average of 4–5 seedlings (Image 2D). Of the total seeds in a capsule, 75% showed viviparous germination. The species which show viviparous germination were collected during a period of almost continuous rainfall in the region. The location of plant was along the sloppy mountain where splash water could easily accommodate the capsule which might be triggered the germination inside the capsule. We presume that due to continuous precipitation and splashing of water from the stream resulting in inducing vivipary in the species. It has been suggested that vivipary is a specialized feature of evolutionary and biological importance that ensures survival of plant (Cota-Sanchez 2004). The results may be useful in large-scale propagation to meet increasing CPT demand and conservation of this valuable medicinal herb.
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