1. INTRODUCTION

Chaba (Piper chaba Hunter) is a herbaceous plant, commonly known as "King of Bitters," in the family Piperaceae. Piperaceae has about 350 species [1]. It grows abundantly in southeastern Asia. i.e., India, Sri Lanka, Pakistan, Java, Malaysia, and Indonesia, while it cultivated extensively in India, China, and Thailand [2]. It is a creeper type flowering vine that spreads on the ground under Piperaceae family. It may also grow around large trees. It is used as spices in meat, fish and mutton curry and other famous dishes. Chaba is called Chui Jhal or Choi Jhal in the Khulna-Jashore region of Bangladesh, Tripura (India) and West Bengal (India). People in Bangladesh's south-western districts like Khulna, Jessore, Bagerhat, Satkhira & Narail cut down the stem, roots, peel the skin and chop it into small pieces and cook them with meat and fish, especially with mutton. The spicy pungent flavor of Choi Jhal is a year-round additive spice. In Indian states of West Bengal and Tripura people use this spice similarly with exception to some people in southern Bengal who prepare a complete dish with the Chaba as the base ingredient, it is very spicy. It is a relatively expensive spice in Bangladesh, and the roots are usually more expensive than the stems because of their stronger aroma. In Bangladesh and India, this plant has many more medicinal values in a wide variety of diseases including asthma, bronchitis, piles, colic pain, dyspepsia and gastralgia [3,4]. Studies have shown that chemicals (pipernonaline, guineensine etc) isolated from the Chaba plant have potential anti-inflammatory, antibacterial, antifungal and analgesic activities. The primary bioactive component of the chaba is a Piperine [5,6]. Piperine has also been shown to have certain serious toxicities such as antifertility [7], respiratory paralysis, hemorrhagic necrosis, urinary bladder and adrenal glands [8]. In Ayurvedic medicine, there are 26 different remedies containing Piper chaba used to treat liver disorders. Administration of Piper chaba Hunter prevented hexachlorocyclohexane induced increase in the activities of glutamyl transpeptidase. glutathione-S-transferase and lipid peroxidation in mouse liver, an indication of potential antioxidant and hepatoprotective effects of Piper chaba Hunter [9]. Potential of chaba as an antioxidant to preserve endothelial function resulting in maintenance of the balance of nitric oxidefendothelin [10]. The arterial narrowing caused by injury to the inner lining of the blood vessel and by high cholesterol in the diet was also found to be decreased by Piper Chaba [11]. Leaves and bark are used for diabetes, malaria and jaundice. The arial part of this plant has also exhibited anti-diarrhoeal, anti-hypertensive, carminative, diuretic, stimulant, expectorant, and smooth muscle relaxant properties [12]. The bark is used for making an external application for pain and chest. Stem is used to reduce post-delivery pain in mothers and also fruitful in rheumatic pains [13]. Chaba fruits were reportedly used as pungent, aromatic, stimulant, anthelmintic, expectorant and carminative [14]. Phytochemical evaluation of P.chaba fruits revealed the presence of various classes of compounds such as lignans, amides, long-chain ester, terpenoids, steroids, pyrones, chalcones and flavonoids [15]. Extracts of chaba stem have also been found to exhibit anti-diarrhoeal and diuretic activities [16]. The fruits are applied as a gastro-protective, anti-flatulent, appetizing property, and also possesses cholesterol lowering properties [17]. The urging for more drug candidates from this kind of natural sources is continuously increasing day by day. In the scenario of increasing demand and lack of recommended varieties, there is immediate need to develop high-yielding varieties in accordance to usage of this plant. In Bangladesh, It is widely known and used throughout the south-western region but these spices are not well known in other parts of the country.

1.1 Botanical Description of Piper chaba

The plant Piper chaba is an herbaceous plant. It is a creeper that spreads on the ground or way take support of other trees. The leaves are simple, oval-shaped and about 3 to 5 inches long opposite and decussate; stipules are lacking. The older leaves are demtate dark in colour and shaped. The flowers are monoecious, zygomorphic and usually are associated with conspicuous, often brightly colored bracts and blossom during the monsoon. The calyx is usually deeply 4-5 lobed or sometimes is highly reduced with more numerous minute teeth. The corolla is sympetalous, usually 5-merous, mostly, zygomorphic and commonly 2 lipped. The androecium usually consists of 4 didynamous stamens or only 2 stamens adnate to the corolla tube or epigynous zone, alternate with the lobes. The gynoecium consists of a single compound pistil of 2 carpels, a single style and a superior ovary with 2 locules, each with usually 2-10 axial ovules in one or two collateral vertical tiers. An annular nectar disk is usually found around the base of the ovary. The fruit looks similar to other varieties of long pepper, with an elongated shape that can grow up to 3 inches long. The fruit is red when ripe, which turns dark brown or black when dry. The seed stalk or funiculus of each seed is modified into a hook shaped jaculator or retinaculum that functions in flinging out the seeds during dehiscence.

2. MATERIALS AND METHODS

The study was carried out at the research field of Regional Spices Research Centre, Magura during 2018-19 to evaluate the performance of different Chaba germplasm and to select the promising one(s) for releasing a variety. The experimental site represents agro-ecological zone (AEZ)-11 recognized as to high Ganges river floodplain. The land was medium high and the soil was clay loam in texture. Germplasm was collected from five upazila under four districts. Vine and sapling was collected during April to July 2018 and transpl anted near different tree species to support for the creeping. Fertilizer and manures were applied according to fertilizer recommendation guide. One light irrigation was given just after transplanting to ensure optimum soil moisture for normal growth and development. The crop was managed by recommended package of intercultural practices. The Observations on different morphological and yield attributing characters viz., % germination, days to germination (d), plant height (cm), number of tiller/plant, number of leaves/plant, leaf length (cm), root length (cm), 1st emergence of spike (days), days to 50% flowering, number of spikes/plant, length of spike (cm), number of seeds/spike, 1000 seeds weight (g), weight of seeds/ plant (g) and seed yield (kg/ha) were recorded from five randomly selected plants from each replications. Collected data were statistically analyzed using MSTAT-C computer package program. Difference between treatments was assessed by Duncan’s Multiple Range Test at 5% level of significance [18]. Table 1. Source of collection of different Chaba germplasm Chaba germplasm Source of collection PCmag001 Chuknagar, Khulna PCmag002 Batiaghata, Khulna PCmag003 Dumoria, Khulna PCmag004 Fakirhat, Bagerhat PCmag005 Tala, Satkhira PCmag006 Monirampur, Jashore 2.1 Collection and Analysis of Soil Nutrients Soil sample was also collected from the exact location from where the germplasm was collected.The soil sample was air dried, ground and sieved. Then the soil sample was ready for analysis. Soil properties were analyzed by using the following methods (Table 2). All soil chemical properties were analyzed in the Regional Laboratory, Soil Resource and Development Institute (SRDI), Batiaghata, Khulna.

3. Soil Nutrient Status

Table 3 showed that nutrients status of different soil that were collected from different Chaba growing area. It was found that average pH was 6.6 to 7.6, electrical conductivity was 2.2 to 6 dS/m, organic matter was 1.1 to 3.5 percent, available potassium was 0.29 to 0.87 meq/100g soil, available phosphorus was 0.07 to 0.16 μg/g soil, available sulfur was 13.47 to 207.70 µg/g soil and available zinc was 0.63 to 2.33 μg/g soil. Morphological data was collected from one year aged plant. Some morphological variations were found among the six germplasm. Leaf shape was ovate in all the germplasm but leaf color varied from green to greenish yellow. Among the six germplasm PCmag-001, PCmag-002, PCmag-004, PCmag-006 were found climbing type and PCmag-003 and PCmag-005 were bushy type. Germplasm PCmag-003 and PCmag-005 were profusely branched and PCmag-001, PCmag-002 PCmag-004 and PCmag-006 were tendrils or twinning type branching behavior. Vine color of germplasm PCmag-003 and PCmag-005 were light green color while germplasm PCmag-001, PCmag-002 PCmag-004 and PCmag-006 were deep gr