A NEW RECORD OF THE CREEPING CUCUMBER, Melothria pendula L. (Cucurbitaceae) FROM HALMAHERA, NORTH MALUKU, INDONESIA

Article Highlights
- Botanical inventory in Halmahera island, North Maluku has found the species Melothria pendula for the first time.
- In Indonesia, the species Melothria pendula is previously known only from Java, Sumatra, Sulawesi, and Lesser Sunda Island.
- DNA barcodes for the species Melothria pendula from Indonesia firstly deposited in NCBI GenBank.

Abstract
This study was conducted to explore Melothria pendula on Halmahera Island. Previously, the species is known to occur in Bali, Sulawesi, Sumatra, Java (Indonesia), Malay Peninsula, Sabah (Malaysia), as well as the Philippines. Results of this study improved insights into the current knowledge about geographic distribution of Melothria. Moreover, the description of the species, habitat, critical taxonomic notes, color plates, distribution map, and DNA barcode were also presented in this study.

INTRODUCTION

The genus Melothria is part of the tribe Benincaseae in the Cucurbitaceae, a family of vines, shrubs, and herbs. This genus, commonly known as "melonettes" or "mouse melons," was first described by Linnaeus in 1753. Melothria species are small to medium-sized herbaceous climbers, with simple leaves, usually small, yellow or white flowers, and berry fruits having smooth surface. The fruits contain a large number of highly compressed seeds, and the testa is typically smooth, white, and often covered with long, appressed hairs(Wilde WJJO & BEE, 2010). These plants require warm weather to thrive and are typically grown as annual crops. Due to rapid growth and spreading habit, the plants are well suited for use on trellises or in hanging baskets. Furthermore, the abundant fruit production throughout the growing season makes the plants to be favored by horticulturists(Sinha et al., 1996)(Mahr, 2014).

Approximately 10 Melothria species have been found in the New World, including M. pendula L. This species is considered a weed and indigenous to the Caribbean, Mexico, Central America, and was reported as locally invasive in West Africa and tropical Asia(Wilde WJJO & BEE, 2010). Melothria pendula has been reported as widely distributed in the Malesian region, including Indonesia (Bali, Java, Sumatra, Sulawesi), Sabah (Borneo), Peninsular Malaysia, the Philippines(Wilde WJJO & BEE, 2006),(Wilde WJJO & BEE, 2010);(Mustaqim & Putra, 2020);(Husaini et al., 2024).

Melothria pendula occurs in a variety of habitats, including moist and seasonal dry tropical woodlands, oak woodlands, cloud woodlands, scrub/thicket, and disturbed areas, at altitudes from 0 to 2,050 m. This species blooms and bears fruits throughout the year(Guerrero-Torres et al., 2022)and in the Philippines, the herb has been traditionally used in treatments of several ailments, including inflammation, constipation, burns, and wounds. In Mexico, the plant has been used for treating anemia, headaches, gonorrhea, and hemorrhoids, as well as for the relief of heart pain. Additionally, the fruits and leaves are edible and can be used in the preparation of a variety of sauces. The medicinal properties of the species are attributed to the phytochemical content, such as alkaloids, anthraquinones, quinones, saponins, steroids, terpenes, and xanthoproteins(, 2021).

Halmahera is the largest island of the Maluku Islands, covering an area of 17,780 km² and a part of North Maluku Province. From a biogeographical stand point, Halmahera is also part of Wallacea, which is known for unique flora and fauna. Wallacea region is rich in minerals, including nickel, cobalt, copper, gold, and silver elements(Konopka et al., 2022). Currently, there are numerous mining projects underway in Halmahera that pose a serious threat to the biodiversity of the island(, 2021), underscoring the need for botanical surveys to understand the species at risk(, 2022). This study was conducted to explore and enumerate the species present at Aketajawe Lolobata National Park and adjacent areas. Furthermore, distribution of Melothria pendula was evaluated to update the geographic distribution range. Selected taxa were also barcoded to provide the sequences in the GenBank.

A total of three specimens of small vines belonging to the Cucurbitaceae family were discovered and collected during a botanical survey in Halmahera Island, North Maluku Province. These vines have small yellow flowers and hanging elliptic fruits resembling small pickles. Locals refer to this plant as timun tikus in Halmahera language, which means mouse cucumber. These collections were gathered from two sites, namely an open, disturbed forest in the area of Geltoli Village, Maba Regency, and a roadside scrub in the area of Saramaake Village, South Wasile Regency, East Halmahera Regency. The plants were subsequently identified as Melothria pendula L. Comparison with literature and herbarium databases, including the Herbarium Bogoriense (BO), GDC, K, L, M, and S (retrieved from GBIF and JSTOR Global Plants), shows that Melothria pendula has not been previously identified. Therefore, this is the first record of the species from Halmahera Island, North Maluku Province.

MATERIALS AND METHODS

Fieldwork was carried out in October 2022 and using the standard herbarium technique described by(Djarwaningsih et al., 2002). The flowering and fruiting specimens were collected, examined, preserved, as well as deposited in Herbarium Bogoriense (BO). The morphological description of this species was determined based on the examination of the fresh plant, the voucher specimen, and the literature. To barcode this species, the internal transcribed spacer (ITS) region was used. Plant Genomic DNA Mini Kit from Geneaid was used to extract the DNA genome from silica gel dried leaves. A pair of ITS-5 (5’-GGA AGT AAA AGT CGT AAC AAG G-3’) as forward primer and ITS-4 (5’-TCC TCC GCT TAT TGA TAT GC-3’) as reverse primer was used for amplification of ITS regions according to White et al. (1990). Heat shock at 95 ºC for 3 minutes was used to start the PCR process and amplification was performed for 35 cycles in three steps. DNA was denatured at 95 ºC for 30 seconds and annealing was performed at 55 ºC for 30 seconds. Furthermore, DNA extension was conducted at 72 ºC for 90 seconds and the final extension occurred at 72 ºC for 5 minutes. Purification and Sanger sequencing were performed by a company, 1^stBase-Singapore, and sequences were deposited in GenBank.

RESULTS AND DISCUSSION

Melothria pendula L. —Figure 1&Figure 2.

Melothria pendula L., Species Plantarum Ed. 1 (1753) 35;

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