Category: Ginger

Kaempferia parviflora Wall. ex Baker, also known as Thai black galingale, Thai ginseng or Cekur Hitam in Malay and Krachaidam in Thailand, is an important medicinal plant from the Zingiberaceae family. K. parviflora is a perennial and herbaceous stemless plant with dark purple rhizomes with a taste that has spiciness to it, but much more subdued than ginger. It is originally found in the North and Northeast of Thailand. The leaves of K. parviflora is approximately 6 to 8 cm long, oblong to lanceolate in shape with red margins, and produces purple and white flowers (Labrooy et al., 2013; Labrooy et al., 2020). In the Zingiberaceae family, Zingiber officinale and Curcuma longa are commonly used in culinary to enhance the taste and aroma of the dishes.

Nowadays, natural product derived medicine is preferable to modern medicine because of its low side effects. K. parviflora is widely used as an alternative medicine in treating various types of diseases including fungal infections, gastrointestinal disorders, and decreased vitality and allergies (Tewtrakul et al., 2008; Trisomboon, 2009). In several studies conducted on K. parviflora, the extract of this plant has potential as an anti-inflammatory, anti-allergies, anti-cancer, anti-plasmodial, anti-fungal, anti-HIV-1 protease activity, and antispasmodic effects (Sookkongwaree et al., 2006; Wattanapitayakul et al., 2008; Sae-wong et al., 2009; Saokaew et al., 2016). It is known as health-promoting herbs and traditionally used as a folk medicine for managing a variety of diseases, including ulcers, gout, colic disorder, abscesses, and osteoarthritis.

This phenomenon has led to the demand for medicinal plants including K. parviflora, to increase drastically. This plant undergoes a vegetative stage for three months and a reproductive stage for two months. This plant produces flowers, but the flowers are inconspicuous and do not produce seeds (Labrooy et al., 2020). The long dormancy period and the inability to set seed affect raw material production for K. parviflora. However, the demand for K. parviflora rhizomes in Malaysia can hardly be fulfilled due to the scarcity of planting materials (Labrooy et al., 2013). Propagation of K. parviflora via conventional propagation is time consuming due to the long dormancy period after senescence, which is approximately 5 to 7 months during November to May according to the Malaysian climate (Techaprasan et al., 2010). To overcome the limited supply of K. parviflora raw materials, plant tissue culture technique plays a pivotal role in cloning the black ginger at mass scale.

Medicinal plants have long been used in the treatment of several diseases throughout the world. Ginger (Zingiber officinale Roscoe), a herbaceous perennial plant from the Zingiberaceae family, is one of those plants. There are 24 genera and 300 species under this family; the genus Zingiber has about 20 species as well (Newman, 2001). It is found in tropical and subtropical regions that bear flowers. It used as a spice, food, flavouring agent, and medicine.

In 2019, the global production of ginger was 4.08 million tons, which demonstrates its significant economic value in world trade (Li et al. 2021). It cannot be sexually propagated due to poor flowering and ginger is an unfertile species that failed to set seed (Kambaska & Santilata, 2009). Therefore, ginger plant possesses perennial tuberous or rhizomatous that are used for its vegetative propagation (Nair, 2019). The plant generates an upright, annual stalk (pseudo-stem), 60 to 90 cm tall, with dark green leaves. Its stalks are covered with flat sheaths that may be taken off stalk; 8 – 12 distiches leaves are present on the stem. The leaves are with long blades, or flat and stalk less blades; are alternative (alternate), lance late, linear lance late, specula, 10 to 21 cm tall and 2 to 2.5 cm wide.

The presence of a high polyphenols and flavonoids content in its leaves, stem, and rhizome has been defined as the critical factor for its pharmacological effects (Ghasemzadeh et al., 2010). These polyphenols and flavonoids compounds are natural sources of antioxidants (Haida et al., 2019). As rhizome is an economically exploited part of the plant, using a high proportion of ginger rhizomes as starting material for cultivating the plant in the next growing season negatively affects its supply in the market. It has been used as spice and medicine for treating cancer (Zhang et al., 2021); cardiovascular disease (Ghafoor et al., 2020); diabetes (Said et al., 2020); and several other illnesses such as cold, nausea, asthma, and cough (Choi et al., 2018). Owing to the global pandemic of COVID-19, ginger consumption gained more interest. It helped alleviate the severe symptoms of COVID-19 positive patients and reduced the recovery time in those patients (Rangnekar et al., 2020).

The success of in vitro technique largely depends on the aseptic culture establishment, shoot regeneration capacity, rooting, and acclimatization. Rhizome buds, which are often used as the source of explants in Zingiberaceae, have been proven to be more responsive. However, the initial establishment of contamination-free culture is difficult owing to the exposure of rhizomes to various soil pathogens (Meenu & Kaushal, 2017; Thakur et al., 2018). These pathogens need to be eliminated by surface sterilization of the explants. Vegetative propagation of ginger has a high risk of spreading infections. Slow propagation rate and the risk of disease transmission by sectioning of the rhizomes have deprived propagation by conventional means. Therefore, plant tissue culture is considered the best alternatives method that may supply a large number of planting materials (Hamirah et al., 2010).