Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020)

TROPICAL AGRICULTURAL SCIENCE

Journal homepage: http://www.pertanika.upm.edu.my/

Analysis of Qualitative and Quantitative Trait Variability among Black Pepper (Piper nigrum L.) Cultivars in

Yi Shang Chen1* and Cheksum Supiah Tawan2

1Malaysian Pepper Board, Jalan Utama, Industrial Area, P.O. Box 1653, , 93916, Malaysia 2Department of Plant Science and Environmental Ecology, Faculty of Resource Science and Technology, Universiti Malaysia Sarawak. Jalan Datuk Mohd Musa, , Sarawak 94300, Malaysia

ABSTRACT This project comprehensively documented the morphological characteristics of ten black pepper cultivars in Malaysia, focusing on diagnosing the morphological difference among the cultivars via qualitative traits. These cultivars are cv. ‘Semongok Aman’, cv. ‘Kuching’, cv. ‘Semongok Emas’, cv. ‘Semongok Perak’, cv. ‘Semongok 1’, cv. ‘Nyerigai’, cv. ‘India’, cv. ‘Lampung Daun Lebar’, cv. ‘’, and cv. ‘Yong Petai’. The morphological characteristics had been evaluated via field-grown vine where the randomized complete block design (RCBD) was adopted and potted vine evaluation via completely randomized design (CRD). Cv. ‘Semongok 1’ showed ovate shaped leaf and anthocyanin free shoot tip; cv. ‘Semongok Aman’ had rounded shape of leaf apex and base; cv. ‘Lampung Daun Lebar’ had an oblique shape in leaf base and ‘Nyerigai’ showed erect type branching; cv. ‘Semongok Emas’ had leaf colour of Green group 137 series (RHS code) and fruit colour of Green group 141 series (RHS); cv. ‘India’ had a lanceolate shaped leaf. At the same time, this study also revealed the key differences in quantitative traits that included leaf area, length-width ratio, inflorescent length, fruit spike length, and fresh to dried berry conversion rate. The study showed that cv. ‘India’ had a low length-width ratio (Lw-1) at 1.52 and lightest seed weight at 4.07(x 10-2)

ARTICLE INFO g; cv. ‘Sarikei’ had the smallest leaf area

Article history: (36.90 cm²), shortest inflorescence (6.06 Received: 8 January 2020 cm), shortest fruit spike (8.07 cm), smallest Accepted: 27 April 2020 Published: 28 August 2020 fruit diameter (5.78 cm), smallest seed diameter (3.84 cm), and thinnest pericarp E-mail addresses: [email protected] (Yi Shang Chen) (1.73 cm); cv. ‘Kuching’ had the greatest [email protected] (Cheksum Supiah Tawan) * Corresponding author number of inflorescence per branch per node

ISSN: 1511-3701 © Universiti Putra Malaysia Press e-ISSN 2231-8542 Yi Shang Chen and Cheksum Supiah Tawan

(ca.58.67) and the greatest number of node/ analysis. Whilst in Malaysia, Chen et al. feet of the stem (ca.4.73); cv. ‘Yong Petai’ (2018) had comprehensive analysis on the had the longest inflorescence (12.75 cm), morphology of ten important cultivars while longest fruit spike (17.07 cm), but thinnest Noorasmah et al. (2018) had also recorded fruit spike (2.90 mm); and, lastly, cv. the inflorescence characteristics of some ‘Semongok Perak’ had the conversion rate important pepper variety. (from fresh to dried black) (36.12 %) and The plant was introduced to Malaysia conversion rate (from fresh to dried white) as early as 1856 (Dalton, 1912), with (24.21 %). The comprehensive evaluation of cultivation focus in the state of Sarawak. both qualitative and quantitative traits of all However, the diversity of the black pepper the black pepper cultivars has ensured the cultivar in Malaysia is unidentified because efficiency of cultivar identification. varietal control is not practised. The most common black pepper cultivars Keywords: Black pepper cultivar, qualitative and are cv. ‘Kuching’ and cv. ‘Sarikei’, both quantitative traits widely planted throughout Sarawak (Sim, 1993), while Paulus (2007) reported three important cultivars in his publication, i.e. INTRODUCTION cv. ‘Semongok Perak’, cv. ‘Semongok Black pepper, scientifically called Piper Aman’, and cv. ‘Kuching’. Through the nigrum L., is known as the ‘King of Spice’ International Pepper Community (IPC) and is the most commonly used spice in exchange program, cv. ‘Lampung Daun the world. The plant is woody perennial Lebar’ and cv. ‘Lampung Daun Kecil’ climber required support, living or non- was introduced to Malaysian farmers living to promote normal growth; leaves (Sim, 1993). A manual entitled ‘Pepper alternate and petiolate type, with shape production technology in Malaysia’ was commonly elliptical, lanceolate or ovate; recently released by the Malaysian Pepper inflorescence of catkin types and the flower Board, mentioning the existence of seven is minute, bracteates, bisexual or unisexual cultivated varieties as common cultivars in and protogynous; the fruit of drupe type Malaysia, including cv. ‘Semongok Aman’, with thin pericarp and seed spherical cv. ‘Semongok Emas’, cv. ‘Kuching’, cv. shaped with diameter 3-5 mm; nodal ‘Semongok Perak’, cv. ‘Uthirancotta’, cv. stem with internode ranged from 8-13 cm ‘Nyerigai’, and cv. ‘PN129’ (Paulus, 2011). when mature; shoot tip purplish-green A total of 47 accessions of black pepper or whitish green (Chen, 2011; Ravindran varieties and 46 accessions of wild Piper et al., 2000). In India, the morphological were reported, conserved in form of a living analyses of black pepper cultivars were plant in the Agricultural Research Centre comprehensively studied by Ravindran (ARC) in Sarawak, Malaysia, from 1957 et al. (1997) through morphometric until 1992 (Sim, 1993).

258 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars

Black Pepper Test Guideline for Plant for the preliminary cultivar’s diagnosis. Variety Protection Act implementation The preliminary diagnosis must show at has been established by the Department of least one distinct character to be eligible Agriculture Malaysia (2009). This guideline for further cultivars verification study. listed the entire important characteristic The pepper germplasm centre situated at for the diagnosis of black pepper variety. Agricultural Research Centre Semongok However, the existing documentation on (ARC) Sarawak, Malaysia was referred for cultivated black pepper in Malaysia is less verification on the cultivar designation. comprehensive, and none of the cultivars To develop a comprehensive guide is registered under the National Crop for cultivar identification, a thorough List of Malaysia. The importance of this assessment of morphological characteristics study is to comprehensively document (qualitative or quantitative traits) had been the morphological characteristics of all conducted. Both potted peppers and field- the important black pepper cultivars in grown vines were assessed in this study. Malaysia, focusing on the diagnosis of Vine growing morphology or vigour was the distinctness among the cultivars. The assessed on field-grown mature vines at the Malaysian government strategized a new three field experimental plots while leaf, policy to ensure the sustainability of the inflorescence, fruit, and seed morphology industry by strengthening the quality of studies were based on samples collected peppercorn. A mono-varietal farm concept from potted mature vines grown under a is believed able to strengthen the quality of controlled environment. Data collection was peppercorn. This can be achieved through carried out from January 2016 to December varietal control, and a pre-requisite to this 2017. Microscopy assessment and data policy is comprehensive documentation on analysis were performed at the Malaysian all important cultivars in the country. Pepper Board, Kuching. The field experiments were conducted MATERIALS AND METHODS at three locations, namely Kampung Jagoi, Extensive fieldwork has been undertaken by Serikin; Kampung Karu, Padawan and the first author since January 2014, to cover Kampung Belawan, . The plots all the possible black pepper cultivation areas were laid out in a Randomized Complete throughout Malaysia, to verify the diversity Block Design (RCBD) (Figure 1) having of black pepper cultivars. The black pepper ten treatment with 5 replications, which are farm distribution info was sourced from T1: ‘Semongok Aman’ vine; T2: ‘Kuching’ the Department of Crop, Extension, and vine, T3: ‘Semongok Emas’ vine; T4: Farmer’s Development, from the Malaysian ‘Semongok Perak’ vine; T5: ‘Semongok Pepper Board. Photography data particularly 1’ vine; T6: ‘Nyerigai’ vine; T7: ‘India’ on the leaf, inflorescence, fruit spike, and vine; T8: ‘Lampung Daun Lebar’ vine; shoot tip were comprehensively generated T9: ‘Sarikei’ vine and T10: ‘Yong Petai’

Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) 259 Yi Shang Chen and Cheksum Supiah Tawan vine. Each trial plot at a different location each treatment, i.e. T1: ‘Semongok Aman’ containing ten treatments consists of vine; T2: ‘Kuching’ vine, T3: ‘Semongok 50 vines. Whilst, a pot experiment was Emas’ vine; T4: ‘Semongok Perak’ vine; T5: conducted under a controlled environment ‘Semongok 1’ vine; T6: ‘Nyerigai’ vine; T7: at the Agriculture Research Center (ARC) ‘India’ vine; T8: ‘Lampung Daun Lebar’ Semongok, Department of Agricultural vine; T9: ‘Sarikei’ vine and T10: ‘Yong Sarawak, using Completely Randomized Petai’ vine. The pot was arranged 1m x 1m Design (CRD) (Figure 2) that consist of a (between vine x between row). The data total of 50 potted vines, with 5 replicates for collection was initiated at 2 years old vine.

T2 T8 T6 T7 T1

T1 T3 T7 T6 T10

T10 T4 T1 T5 T9

T9 T7 T2 T1 T8

T8 T6 T9 T2 T3

T3 T5 T8 T4 T7

T4 T1 T3 T3 T2

T7 T2 T10 T8 T4

T6 T9 T4 T10 T5

T5 T10 T5 T9 T6

Figure 1. Randomized complete block design (RCBD) for the field-grown vine of ten cultivars. T1: ‘Semongok Aman’ vine; T2: ‘Kuching’ vine; T3: ‘Semongok Emas’ vine; T4: ‘Semongok Perak’ vine; T5: ‘Semongok 1’ vine; T6: ‘Nyerigai’ vine; T7: ‘India’ vine; T8: ‘Lampung Daun Lebar’ vine; T9: ‘Sarikei’ vine, and T10: ‘Yong Petai’ vine. Each block is differenced by topography elevation

T1 T4 T2 T4 T7 T6 T7 T5 T7 T2

T3 T8 T3 T8 T8 T2 T8 T5 T8 T6

T10 T10 T1 T6 T1 T2 T10 T1 T3 T8

T2 T10 T8 T3 T5 T4 T6 T3 T1 T10

T4 T5 T6 T8 T5 T8 T7 T8 T4 T7

Figure 2. Completely randomized design (CRD) pot arrangement for experimental plot under a controlled environment. T1: ‘Semongok Aman’ vine; T2: ‘Kuching’ vine; T3: ‘Semongok Emas’ vine; T4: ‘Semongok Perak’ vine; T5: ‘Semongok 1’ vine; T6: ‘Nyerigai’ vine; T7: ‘India’ vine; T8: ‘Lampung Daun Lebar’ vine; T9: ‘Sarikei’ vine, and T10: ‘Yong Petai’ vine

260 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars

A total of 26 morphology characteristics, listed in Table 1. A dichotomous key for consisting of both qualitative and quantitative diagnosing the cultivars was constructed as traits, had been assessed in this study, as the outcome for this study.

Table 1 Morphological characteristic used for diagnosis of cultivar distinctness Morphological character Measurement methods

1. Leaf characters Leaf shape; leaf apex and leaf base Description based on UPOV standard Leaf area (cm²); blade width (w) mm; Measured by WinFOLIA image analysis blade length (L) mm and blade length- system width ratio (Lw-1) Leaf colour (fully expanded leaf) RHS colour codes used 2. Inflorescence characters Inflorescence length at stigma withering Measured by Vernier calliper stage (cm) and Inflorescence thickness at stigma withering stage (mm)* Inflorescence colour Number of flowers per inflorescence RHS colour codes used Number of inflorescence (spike) per Counted via stereomicroscope branch per node Counted manually 3. Fruit characters Fruit spike length (cm) and fruit size in Measured by Vernier calliper diameter (mm) Fruit weight (single fresh berry) (g) Measured by analytical balance Fruit colour (hard dough stage) RHS colour codes used Per cent fruit set (%) Counted manually. Percent = (Number of developed fruit)/ (Number of developed fruit + number of underdeveloped fruit) Conversion rate % (fresh to black x 100%. pepper) Measured by analytical balance (Drying specification: Oven dry at 40°C; Conversion rate % (fresh to white moisture content ≤12%) pepper) Measured by analytical balance (Drying specification: Oven dry at 40°C; Pericarp thickness (mm) moisture content ≤12%) Measured by Vernier calliper (Horizontal diameter of fresh berry - Horizontal diameter of seed) 4. Seed characters Seed diameter (mm) Measured by Vernier calliper (Horizontal diameter of seed) Seed weight (g) Measured by analytical balance

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Table 1 (Continued) Morphological character Measurement methods

5. Vigour Branch column By observation Internode length (cm) Measurement by a ruler (Node to node distance) Number of node /1feet stem Counted manually 6. Shoot tips Anthocyanin: Absent or present By observation on shoot tip colouration Greenish colour = Absent of anthocyanin; Purplish colour = Present of anthocyanin

Note. UPOV- International Union for the Protection of New Varieties of Plants; RHS - Royal Horticultural Society

RESULTS AND DISCUSSIONS Daun Lebar’ (LDL), ‘Sarikei’ (SAR), In this study, a total of ten black pepper and ‘Yong Petai’ (YP). Comprehensive cultivars have been assessed, including assessment consisting of both qualitative cultivars ‘Semongok Aman’ (SA), and quantitative traits had been carried ‘Kuching’ (KCH), ‘Semongok Emas’ (SE), out to reveal key diagnostic morphology ‘Semongok Perak’ (SP), ‘Semongok 1’ (S1), for each of the cultivars. The results of the ‘Nyerigai’ (NYE), ‘India’ (IND), ‘Lampung assessment are shown in Table 2.

Table 2 Qualitative and quantitative traits used to diagnose the differences among black pepper cultivars

Morphological Cultivars No. characteristic SA KCH SE SP S1 Leaf (Refer to Figure 3) 1. Leaf shape Elliptical Ovate Elliptical Elliptical Cordate 2. Leaf apex Mucronate Acute Acute Acute Acute 3. Leaf base Acute Rounded Acute Oblique Cordate 4. Leaf area (cm²) 45.40abc 37.70ab 46.60bc 62.80d 132.60f 5. Blade width (w) 6.36b 5.37a 5.67a 7.47c 11.87e 6. (cm) 10.70a 10.83a 13.31c 13.20c 16.67e 7. Blade length (L) 1.70b 2.02d 2.35ef 1.77bc 1.41a (cm) 8. Blade length-width Green Green Green Green Green ratio (Lw-1) group 139 group 139 group 137 group group Leaf colour (fully series series series NN137 139 expanded leaf) series

262 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars

Table 2 (Continued) Morphological Cultivars No. characteristic NYE IND LDL SAR YP Leaf (Refer to Figure 3) 1. Leaf shape Elliptical Lanceolate Ovate Elliptical Elliptical 2. Leaf apex Acute Acuminate Acute Acute Acute 3. Leaf base Oblique Rounded Oblique Acute Acute 4. Leaf area (cm²) 53.60c 50.90c 81.40e 36.90a 66.50d 5. Blade width (w) 6.49b 5.75a 8.85d 5.26a 6.62b 6. (cm) 12.07b 13.63c 13.50c 10.93a 14.75d 7. Blade length (L) 1.86c 2.39f 1.52a 2.10d 2.24e (cm) 8. Blade length- Green Green group Green Green Green width ratio (Lw-1) group 139 139 series group group 139 group 139 Leaf colour (fully series NN137 series series expanded leaf)

Morphological Cultivars No. characteristic SA KCH SE SP S1 Inflorescence (Refer to Figure 4) 7.84d 7.03bc 7.95d 6.93b 12.40e 9. Inflorescence length (cm) 3.50d 3.56d 3.47d 3.73e 3.85f 10. Inflorescence thickness (mm) Green Green Green Green Green 11. Inflorescence group 144 group group group 145 group colour series N144 N144 series N144 88.30de 67.57ab 86.33de 72.70abc 127.90g 12. Number of 12.47a 58.67f 19.57abc 22.20bc 17.60ab flowers per 13. inflorescence (average) Number of inflorescence (spike) per branch per node (average)

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Table 2 (Continued) Morphological Cultivars No. characteristic NYE IND LDL SAR YP Inflorescence (Refer to Figure 4) 9. Inflorescence length 7.06bc 7.80d 7.68cd 6.06a 12.75e (cm) 10. Inflorescence thickness 3.10c 3.00b 3.75e 3.54d 2.90a (mm) 11. Inflorescence colour Green Green Green Green Green group group group 144 group group N144 N144 series N144 145 12. Number of flowers per 73.77bc 80.40cd 100.53f 65.10a series inflorescence (average) 93.57ef 13. Number of 35.83e 27.37cd 21.47bc 34.73de inflorescence (spike) 16.20ab per branch per node (average)

Morphological Cultivars No. characteristic SA KCH SE SP S1 Fruit (Refer to Figures 5 and 6) 14. Fruit spike length (cm) 10.38c 9.37b 10.62c 9.27b 16.48d

15. Fruit size in diameter 6.68e 6.75e 6.76e 6.86e 7.27f (mm) 16. Fruit weight (single 0.20d 0.17b 0.17b 0.19c 0.20d fresh berry) (g) 17. Fruit colour (hard Green Green Green Green Green dough stage) group group group group group NN137 NN137 141 NN137 NN137 series series series series series 18. Per cent fruit set (%) 70.68f 61.10bc 68.75ef 61.51bc 64.24cde 19. Conversion rate (%) 37.35ab 41.68cd 42.24cd 36.12a 42.35d (fresh to black pepper) 20. Conversion rate (%) 30.37de 31.08e 31.68e 24.21a 27.70bc (fresh to white pepper) 21. Pericarp thickness 2.00bc 2.20c 2.16bc 2.22cd 2.46de (mm)

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Table 2 (Continued) Morphological Cultivars No. characteristic NYE IND LDL SAR YP Fruit (Refer to Figures 5 and 6) 14. Fruit spike length (cm) 9.39b 10.38c 10.22c 8.07a 17.07d 15. Fruit size in diameter 6.48d 6.02b 6.30c 5.78a 7.27f (mm) 16. Fruit weight (single 0.14a 0.14a 0.15a 0.17b 0.19cd fresh berry) (g) 17. Fruit colour (hard Green Green Green Green Green dough stage) group group group 139 group group NN137 NN137 NN137 NN137 series series series series 18. Per cent fruit set (%) 66.93def 65.76cdef 55.10a 64.28cde 56.26ab 19. Conversion rate (%) 41.06bcd 40.51bcd 38.31abc 39.55abcd 36.25a (fresh to black pepper) 20. Conversion rate (%) 31.89e 28.16cd 29.62cde 29.69cde 25.70ab (fresh to white pepper) 21. Pericarp thickness 2.25cd 1.94ab 2.06bc 1.73a 2.69e (mm)

Morphological Cultivars No. characteristic SA KCH SE SP S1 Seed (Refer to Figure 6) 22. Seed diameter (mm) 4.80e 4.44c 4.60d 4.60d 4.82e 23. Seed weight (g) (x 10-2) 6.11g 5.13e 5.40f 4.85d 5.46f

Morphological Cultivars No. characteristic NYE IND LDL SAR YP Seed (Refer to Figure 6) 22. Seed diameter (mm) 4.44c 3.90a 4.32b 3.84a 4.45c 23. Seed weight (g) 4.91d 4.07a 4.30b 4.56c 4.98de (x 10-2)

Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) 265 Yi Shang Chen and Cheksum Supiah Tawan

Table 2 (Continued)

Morphological Cultivars No. characteristic SA KCH SE SP S1 Vigour 24. Branch column Horizontal Horizontal Drooping Horizontal Horizontal 25. types 11.42e 8.33a 11.40e 10.10cd 8.73ab 26. Internode length 3.67ab 4.73f 3.33a 4.13cdf 4.17cdf (cm) Number of node /feet of stem (average)

Morphological Cultivars No. characteristic NYE IND LDL SAR YP Vigour 24. Branch column Erect Horizontal Drooping Horizontal Horizontal 25. types 9.77bc 9.57bc 11.23de 9.83bc 12.7f 26. Internode length 3.83bc 4.30de 4.43ef 3.97bcd 3.33a (cm) Number of node /feet of stem (average)

Morphological Cultivars No. characteristic SA KCH SE SP S1 Shoot tips (Refer to Figure 7) 27. Anthocyanin: Present Present Present Present Absent Absent or present

Morphological Cultivars No. characteristic NYE IND LDL SAR YP Shoot tips (Refer to Figure 7) 27. Anthocyanin: Present Present Present Present Present Absent or present Note. SA - ‘Semongok Aman’; KCH - ‘Kuching’; SE - ‘Semongok Emas’; SP - ‘Semongok Perak’; S1 - ‘Semongok 1’; NYE - ‘Nyerigai’; IND - ‘India’; LDL - ‘Lampung Daun Lebar’; SAR - ‘Sarikei’, and YP - ‘Yong Petai’. Means followed by the different superscript letter within the same row are significantly different Pat ≤0.05

266 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars

The dichotomous key for cultivar Identification key to black pepper cultivars diagnosis was constructed by considering in Malaysia: both the qualitative and quantitative traits of the ten black peppers.

1a Leaf area <80 cm² 2 5a Inflorescence 6 (fully developed thickness 2.8-3.2 mm leaf from matured thick; Internode 9-10 and vigorous vine); cm long Number of flowers 5b Inflorescence 7 per inflorescence less thickness 3.2-4.0 mm than 90 thick; Internode 10- 1b Leaf area >80 cm² 8 11 cm long (fully developed 6a Leaf shape ‘India’ leaf from matured lanceolate; Leaf and vigorous vine); apex acuminate; Number of flowers Plagiotropic per inflorescence branching horizontal more than 90 type 2a Blade length less than 3 6b Leaf shape elliptical; ‘Nyerigai’ 11 cm long; Blade Leaf apex acute; width-length ratio Plagiotropic -1 (Lw ) ranged from branching erect type 2.0 to 2.3 7a Mature leaf, blueish- ‘Semongok 2b Blade length more 4 green colour (RHS Emas’ than 12 cm long; colour code: Green Blade width-length group137 series); -1 ratio (Lw ) ranged Mature unripe fruit, from 1.7 to 2.0 or pale green (RHS >2.3 colour code: Green 3a Pericarp thickness ‘Kuching’ group 141 series) 2.0-2.2 mm thick; 7b Mature leaf, greyish ‘Semongok Seed weight 5.0-5.2 green colour (RHS Perak’ -2 (x 10 ) g colour code: Green 3b Pericarp thickness ‘Sarikei’ group NN137); 1.6-1.8 mm thick; Mature unripe fruit, Seed weight <4.8 (x dark green (RHS 10-2) g colour code: Green 4a Leaf base acute; ‘Semongok group NN137 series) Percent fruit set Aman’ 8a Anthocyanin absent ‘Semongok >70% in shoot tip (green 1’ 4b Leaf base rounded; 5 whitish colour); Seed -2 Percent fruit set 60- weight, >5.4(x 10 ) 70% g; internode length, 8 - 9 c m

Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) 267 Yi Shang Chen and Cheksum Supiah Tawan

8b Anthocyanin present 9 in shoot tip (Purplish green colour); Seed weight, <4.8(x 10-2) g or 4.8-5.0(x 10-2) g; internode length, >11 cm 9a Fruit spike length, ‘Lampung 7-9 cm; Fruit size in Daun diameter, 6-7 mm Lebar’ 9b Fruit spike length, ‘Yong >11 cm; Fruit size in Petai’ diameter, >7 mm

Figure 3. Cultivar designation and leaf shape. A. cv. ‘Semongok Aman’- Elliptical; B. cv. ‘Kuching’- Ovate; C. cv. ‘Semongok Emas’- Elliptical; D. cv. ‘Semongok Perak’- Elliptical; E. cv. ‘Semongok 1’- Cordate; F. cv. ‘Nyerigai’- Elliptical; G. cv. ‘India’- Lanceolate; H. cv. ‘Lampung Daun Lebar’- Ovate; I. cv. ‘Sarikei’- Elliptical; J. cv. ‘Yong Petai’- Elliptical. Scale bar: 1cm

268 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars

Figure 4. Inflorescence. SA - ‘Semongok Aman’; SE - ‘Semongok Emas’; KCH - ‘Kuching’; SP - ‘Semongok Perak’; NYE - ‘Nyerigai’; SAR - ‘Sarikei’; IND - ‘India’; S1 - ‘Semongok 1’; YP - ‘Yong Petai’, and LDL - ‘Lampung Daun Lebar’. Scale bar: 2cm

Figure 5. Fruit spike. SA - ‘Semongok Aman’; KCH - ‘Kuching’; SE - ‘Semongok Emas’; SP - ‘Semongok Perak’; S1 - ‘Semongok 1’; NYE - ‘Nyerigai; IND - ‘India’; LDL - ‘Lampung Daun Lebar’; SAR - ‘Sarikei’, and YP - ‘Yong Petai’. Scale bar: 2cm

Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) 269 Yi Shang Chen and Cheksum Supiah Tawan

Figure 6. Cross section of ripe and mature fruit. A. ‘Semongok Aman’; B. ‘Kuching’; C. ‘Semongok Emas’; D. ‘Semongok Perak’; E. ‘Semongok 1’; F. ‘Nyerigai; G. ‘Lampung Daun Lebar’; H. ‘Sarikei’, and I. ‘Yong Petai’. Scale bar: 2mm

Figure 7. Shoot tips. SA - ‘Semongok Aman’; KCH - ‘Kuching’; SE - ‘Semongok Emas’; SP - ‘Semongok Perak’; S1 - ‘Semongok 1’; NYE - ‘Nyerigai; IND - ‘India’; LDL - ‘Lampung Daun Lebar’; SAR - ‘Sarikei’, and YP - ‘Yong Petai’. Scale bar: 1cm

270 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars

Qualitative trait analysis showed study showed qualitative traits are more leaf shape, leaf apex, leaf base, branch influential compared to quantitative traits. column types (branching behaviour), and This is supported by Khan et al. (2015), anthocyanin colouration at shoot tip were Olakojo and Adetula (2014), and Stephan crucial for diagnosing morphological et al. (2016). However, qualitative traits differences among cultivars. Most of the alone with limited variability are insufficient cultivars exhibited elliptical shaped leaf; for the diagnosis of certain black pepper however, cultivar ‘India’ had a lanceolate cultivars. In this study, the ANOVA test shaped leaf and the cultivar ‘Semongok proved the variability for quantitative traits 1’ exhibited cordate-shaped leaf. Thus, was more substantial compare to qualitative leaf shape distinctness is an important key traits. The analysis showed seed weight diagnosis for the two cultivars. Leaf apex is among the most important quantitative observation showed cultivar ‘Semongok trait, exhibiting seven significantly different Aman’ was substantially distinct, with groups among the ten cultivars. Next are a mucronate-shaped leaf apex; thus, the traits like blade length-width ratio, fruit cultivar could be identified through this size in diameter, conversion rate (%) (fresh trait easily. The only cultivar ‘Lampung to black pepper), inflorescence thickness, Daun Lebar’ showed ovate leaf shape and number of inflorescence per branch per oblique leaf base at the same time, another node, number of flower per inflorescence, important key diagnosis. In branch column per cent fruit set (%), number of node/feet of analysis, most cultivars showed a horizontal the stem, and internode length that exhibited type of branching, but the cultivar ‘Nyerigai’ six significant groups in the ANOVA test, exhibited an erect type of branching, while respectively. The quantitative traits of blade both cultivar ‘Semongok Emas’ and cultivar width, blade length, pericarp thickness, seed ‘Lampung Daun Lebar’ exhibited a drooping diameter, and conversion rate (fresh to white type. Another important key diagnosis is to pepper) showed five significant different shoot tip colouration analysis, where the groups, also an important diagnosis key arrival of anthocyanin at the shoot tip will for the ten black pepper cultivars. Thus, lead to an exhibition of a purplish colour. the quantitative plays a pivotal role as an Among the ten cultivars, the only cultivar additional indicator when the qualitative ‘Semongok 1’ was anthocyanin-free at the traits are unable to assist the identification. shoot tip, thus exhibiting a whitish-green The phenetic analysis was done by shoot tip. However, qualitative traits, like Chen et al. (2018) revealing that cultivars leaf colour and inflorescence colour, were ‘Semongok Aman’ and ‘Semongok 1’ had less substantial for the diagnosis, because high distinctive values for identification, the colour intensity is influenced greatly by thus varietal diagnostic could be very easy. biotic and abiotic factors (Anita & Anna, Cultivars ‘Nyerigai’, ‘India’, ‘Semongok 2012; Szakiel et al., 2011). Analyses in this Perak’, and ‘Semongok Emas’ were grouped

Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) 271 Yi Shang Chen and Cheksum Supiah Tawan in the most diverse cluster among all per cent of fruit set. This cultivar exhibited clusters. The four cultivars had a similarity per cent fruit set as high as 76%, averagely. index as high as 92%; however, investigation Qualitative trait analysis also discovered on leaf width, leaf width-length ratio, seed the morphological distinctness of cultivar weight, and conversion rate (fresh to black ‘Lampung Daun Lebar’. This cultivar pepper) could determine the characteristic showed ovate leaf shape and oblique leaf differences. Cultivar ‘Lampung Daun base at the same time, unique among all the Lebar’ and the cultivar ‘Yong Petai’ had a cultivars. The identification for this cultivar similarity of 96%; however, the two showed was further supported by the quantitative distinctive differences on leaf width, leaf trait of blade length-width ratio (Lw-1), length-width ratio, spike thickness, and where the cultivar showed the lowest ratio spike length characteristics. The study also among all cultivars. Cultivar ‘Nyerigai’ reported cultivars ‘Kuching’ and ‘Sarikei’ exhibited a unique branching behaviour showed the highest similarity index, thus (branch column type) of an erect type, while were among the most difficult cultivars to others exhibited horizontal or drooping diagnose morphological differences. This behaviour. The only cultivar that showed a finding proved the importance of both distinctness in leaf and fruit colouration was qualitative analysis and quantitative analysis cv. ‘Semongok Emas’, with the leaf colour in varietal identification of black pepper of green group 137 series (RHS code) and cultivars. fruit colour of green group 141 series (RHS). Cultivar ‘India’ exhibited a lanceolate CONCLUSIONS shaped leaf, an important diagnosis key for Qualitative trait analysis has assisted the this cultivar. Quantitative trait uniqueness diagnosis of ten important cultivars of black for this cultivar was seed weight; it was pepper in Malaysia as mentioned above the lightest seed among all. Cv. ‘Kuching’, while the quantitative traits are crucial as cv. ‘Sarikei’, cv. ‘Semongok Perak’, and an additional indicator for the diagnosis cv. ‘Yong Petai’ did not show qualitative beside played the role as an indicator of trait distinctness; however, quantitative the potential agronomic performance of the trait analysis had assisted the diagnosis. cultivar. This study showed cv. ‘Semongok Cv. ‘Sarikei’ had a great distinctness in 1’ exhibited two distinct qualitative traits, quantitative traits, including the smallest a cordate shaped leaf and anthocyanin free leaf area, shortest inflorescence and fruit shoot tip, and was among the easiest cultivar spike, smallest fruit and seed size, and to identify. Another cultivar with two distinct thinnest pericarp. Cv. ‘Kuching’ showed qualitative traits is cv. ‘Semongok Aman’, the highest number of inflorescence (spike) with mucronate shaped leaf apex. The per branch per node and the greatest number identification for this cultivar can be further of node/feet of the stem, while cv. ‘Yong verified by quantitative traits, counting the Petai’ had the longest inflorescence and

272 Pertanika J. Trop. Agric. Sci. 43 (3): 257 - 274 (2020) Morphological Analysis of Black Pepper Cultivars fruit spike, but the thinnest fruit spike. Cv. November 25, 2019, from https://www.hindawi. ‘Semongok Perak’ only showed significant com/journals/ija/2018/3894924/ variability in the conversion rate (from fresh Dalton, G. (1912). Pepper growing in upper Sarawak. to dried berry), with the lowest rate in both Sarawak Museum Journal, 1(2), 55. conversions to black (pericarp remained) Department of Agriculture Malaysia. (2009). Plant and white (pericarp removed) peppercorns. variety protection: Guidelines for the conduct The findings of this study enable efficient of tests for distinctness, uniformity and stability identification of black pepper cultivar on black pepper (Piper nigrum L.). Putrajaya, in Malaysia. This is prerequisite toward Malaysia: DOA. implementation of the varietal regulation Khan, S. A., Shah, A., Abbasi, F., Javed, A., Rahman, act in the country, at the same time serve as I. U., & Ahmad, H. (2015). Quantitative and conservation information for the crop. qualitative traits analyses in the advance breeding lines of rice. International Journal of Biosciences, 6(8), 50-61. ACKNOWLEDGMENTS Noorasmah, S., Nurul A’in, J., & Shiamala, D. R. The authors would like to thank Mr. Kevin (2019). Flower composition of black pepper Muyang Anak Tawie for assistance in (Piper nigrum L.) varieties in , Sarawak. morphological assessment via WinFOLIA In 28th Malaysian Society of Plant Physiology image analysis system. Appreciation also Conference: Challenges and strategies for plant goes to Mr. Wan Ambi and Mr. Juvian productivity and resilience, Kelantan, Malaysia, 28-30 August 2018 (pp. 33-38). Serdang, Jacob, research assistants of the Malaysian Malaysia: Malaysian Society of Plant Physiology Pepper Board, for their excellent technical (MSPP). assistance in the field. This project is fully Olakojo, S. A., & Adetula, O. A. (2014). Comparison funded by the Malaysian Pepper Board, of qualitative and quantitative traits of some sourced from the Economic Planning Unit advanced breeding lines of tomato (Lycopersicon (EPU) of Malaysia. esculentum L.). African Journal of Plant Science, 8(10), 457-461.

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