Heliyon 7 (2021) e07940 Contents lists available at ScienceDirect Heliyon journal homepage: www.cell.com/heliyon Research article Evaluation of growth and yield traits in rice genotypes using multivariate analysis Jiban Shrestha *, Sudeep Subedi, Ujjawal Kumar Singh Kushwaha, Bidhya Maharjan Nepal Agricultural Research Council, National Plant Breeding and Genetics Research Centre, Khumaltar, Lalitpur, Nepal A R T I C L E I N F O A B S T R A C T Keywords: Clusters Grain yield Plant height Rice Rice (Oryza sativa L.) is the first staple crop in terms of production and area of cultivation in Nepal. The amount of genetic variability is important factor in identifying suitable genotypes in rice breeding programs. This study was conducted in Khumaltar, Lalitpur, Nepal during rainy seasons of 2018 and 2019. Forty rice genotypes were planted in Alpha Lattice Design with two replications to determine the genetic diversity among them. The rice genotypes were grouped into 7 clusters based on growth and yield traits. The traits sucnamely plant height, panicle length, number of tillers/plant and grain yield were found highly significant (p < 0.01). Rice genotypes NR 10676-B-1-3-3-3 produced the highest yield (5.65 t/ha), followed by NR10410-89-3-2-1-1 (5.54 t/ha). The highest distance between cluster centroids (83.51) was found in the cluster 2 (Bange Masino, Hansa raj, Indrabeli, NR 11178-B-B-6-1, NR 11368-B-B-17, Pokhreli Jethobudho, Pokhreli Masino), and cluster 4 (IR73008-136-2-2-3, IR74052-95-3-2) indicating genetic dissimilarity among the genotypes which can be utilized in a hybrid breeding programme. Genotypes of cluster 2 had the highest grain yield (4.97 t/ha). The results of this study suggest that genotypes grouped in cluster 2 can be grown for higher grain production in mid-hills of Nepal. 1. Introduction Rice (Oryza sativa L.) is one of the leading staple food crops, feeding over half of the world's population (Ricepedia, 2020; USDA, 2020). In Asia, it is grown to the tune of 90% of the world's supply (Paranthaman et al., 2009). In Nepal rice is the first staple food crop, contributing significantly to the country's economy and supplying a substantial share of people's livelihoods. It is grown on 1.49 million hectares with a total yield of 5.61 million tons and a productivity of 3.76 t/ha in Nepal (CBS, 2018). Development of rice varieties with enhanced yield potential is a objective in rice breeding program in Nepal. A number of varieties of rice have been developed and adapted in the different agro-ecosystems of the country (Joshi, 2017). Breeders use different methods for identifying superior rice varieites; among these methods, multivariate analysis is the most commonly used approach for assessing genetic variability. To maintain high productivity levels, genetic diversity is essential (Tripathi et al., 2013). When it comes to selecting the right kind of parents for a hybridization programme, it is the most important tool for a plant breeder. The use of genetic divergence to select parents for a successful hybridization and breeding program is a smart idea (Vivekananda and Subramanian, 1993). According to Kwon et al. (2002), identifying parents based on divergence study is more beneficial for any breeding program. The measurement of genetic diversity across and within groups or clusters is critical for the right selection of parents in the rice breeding program (Murty and Arunachalam, 1966). According to Singh and Chaudhary (1977), the identification of traits responsible for genetic variation among populations can help in the selection of varied parents for hybridization programs. Cluster analysis with Euclidean distance is a valuable statistical approach for determining the genetic diversity of germplasm collections in terms of the traits taken collectively. Many researchers had successfully used agro-morphological characters to classify and estimate diversity in a variety of rice using multivariate analyses (Nachimuthu et al., 2014; Ravikumar et al., 2015). The objectives of this study were to determine the degree of diversity and to identify potential genotypes for rice hybridization based on morphological traits. 2. Materials and methods 2.1. Plant materials Forty rice genotypes were selected and used in this study. The source of genotypes was National Plant Breeding and Genetics Research Centre (NPBGRC), Khumaltar, Lalitpur, Nepal. * Corresponding author. E-mail address: jibshrestha@gmail.com (J. Shrestha). https://doi.org/10.1016/j.heliyon.2021.e07940 Received 15 June 2021; Received in revised form 30 August 2021; Accepted 2 September 2021 2405-8440/© 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/). J. Shrestha et al. Heliyon 7 (2021) e07940 Table 1. Meteorological data of the experimental location in 2018. Months Maximum Temperature (oC) Minimum Temperature (oC) Rainfall (mm) July 28.1 20.8 387.3 August 27.7 20.5 322.0 September 28.4 19.2 53.2 October 25.9 11.8 0 November 22.8 6.9 0 December 18.5 3.6 Table 3. Mean values of various growth and yield traits of 40 rice genotypes at Khumaltar, Lalitpur in 2018. 0.9 (Source: NARC, 2019) Table 2. Meteorological data of the experimental location in 2019. Months Maximum Temperature (oC) Minimum Temperature (oC) Rainfall (mm) July 27.9 20.6 446.1 August 29.2 20.9 172.8 Genotypes Plant height (cm) Panicle length (cm) No. of tillers/ plant Grain yield (t/ha) 08FAN10 96.00 23.50 14.00 5.25 Aanga 94.00 20.50 15.00 4.48 Bange masino 172.50 22.25 10.00 4.40 Basmati-370 110.50 25.50 11.00 3.40 Hansa raj 166.50 22.00 14.00 4.05 3.72 Himali 120.00 21.00 13.00 Indrabeli 166.00 26.50 13.00 3.35 IR 87751-20-4-42 100.00 25.70 10.00 5.27 IR 87759-1-2-2-11 101.00 26.20 11.00 5.10 IR 88968-2-1-1-2 97.50 26.90 12.00 4.93 IR67017 91.00 26.50 11.00 4.68 IR70422-95-1-1 97.50 21.00 12.00 3.10 84.50 22.70 14.00 2.80 September 27.0 19.5 239.9 IR73008-136-22-3 October 26.0 14.4 3.0 IR74052-95-3-2 85.00 25.00 16.00 3.54 November 24.1 10.1 0 92.00 26.50 13.00 3.59 December 18.2 3.5 29.2 IR77512-128-21-2 (Source: NARC, 2020) 2.2. Experimental site These experiments were carried out in the research field of National Plant Breeding and Genetics Research Centre, Khumaltar, Laltipur, Nepal. It is located at 27 400 000 N latitude, 85 200 000 E longitude, and altitude of 1350 m above sea level (NARC, 2018). The soil of the research plot is clayey loam. 2.3. Climatic data The climatic data during the experimental periods (2018 and 2019) are given in Table 1 and Table 2. 2.4. Experimental design and cultural practices Forty rice genotypes were planted in the first week of July 2018 and 2019. The rice genotypes were evaluated in Alpha lattice design with two replications. Rice was planted at a spacing of 20 cm 15 cm. The area of the plot was 6 m2. The fertilizers at a rate of 100:40:40 N:P:K [(nitrogen (N), phosphorus (P) and potassium (K)]/ha was applied via Urea, Diammonium Phosphate DAP, and Muriate of Potash (MOP). kg/ha. As a base dose, the full dosages of P2O5 and K2O, as well as half of the dose of N, were utilized, and the remaining 50% nitrogenous fertilizer was divided into two halves. The first was applied during the tillering stage, and the second was during the booting step. Other cultural practices were carried out according to guidelines provided by the National Rice Research Program, Hardinath, Dhanusha, Nepal. IR77512-2-1-2-2 102.50 26.70 13.00 4.34 IR775-39-80-2-22 93.50 22.00 14.00 4.82 Lalka basmati 107.00 26.50 14.00 3.57 NR 10676-B-1-33-3 128.50 25.00 16.00 5.55 NR 11130-B-B-B3-3 145.00 26.50 10.00 5.00 NR 11133-B-B-B23-2 139.00 26.50 9.00 4.81 NR 11142-B-B-B9 145.00 27.75 7.00 4.82 NR 11156-B-B-10 137.50 23.30 9.00 4.40 NR 11178-B-B-61 164.50 26.20 9.00 5.39 NR 11182-B-12 132.00 26.50 15.00 5.30 NR 11182-B-21 96.50 21.00 9.00 4.19 NR 11196-B-3-3 167.50 30.80 8.00 4.94 NR 11281-B-B-11 143.00 26.90 9.00 5.08 NR 11367-B-B-10 151.50 25.40 9.00 4.47 NR 11368-B-B-17 168.50 26.75 8.00 4.48 NR 11374-B-B-11 123.50 21.30 14.00 4.71 NR 11410-B-B-9 149.00 26.70 7.00 5.39 NR10410-89-3-21-1 129.00 26.50 15.00 5.54 Pokhreli Basmati 151.50 26.50 13.00 4.20 Pokhreli Jethobudho 172.45 24.25 9.00 3.56 Pokhreli Masino 180.00 23.20 9.00 3.56 Sali dhan 125.00 27.20 8.00 3.10 Sugandha-2 110.00 23.50 11.00 2.89 Sugandha-3 97.50 24.00 12.00 4.96 2.5. Data recording and analysis Sunaulo Sughandha 102.50 22.50 16.00 2.30 Plant height, panicle length, number of tillers/plant, and grain yield were recorded. The grain yield was calculated using the formula adopted by Poudel (1995) and Shrestha et al. (2020a) (Eq. 1). GM 125.90 24.88 12.00 4.33 SEM 6.51 1.93 0.96 0.28 P value <.001 <0.001 <.001 <.001 kg ð100MÞPlotyield ðkgÞ10000m2 Grainyield at12%moisture¼ ha ð10012ÞNetplotarea; m2 (1) CV(%) 5.17 7.75 8.28 6.40 LSD (0.05) 13.21 3.91 1.94 0.56 GM: Grand mean, SEM: Standard error of mean, CV: Coefficient of variation, LSD: Least significant difference. Where, M is the grain moisture content in percentage. 2 J. Shrestha et al. Heliyon 7 (2021) e07940 Table 4. Mean values of various growth and yield traits of 40 rice genotypes at Khumaltar, Lalitpur in 2019. Table 5. Combined mean values over years (2018 and 2019) of various growth and yield traits of 40 rice genotypes at Khumaltar, Lalitpur. Genotypes Plant height (cm) Panicle length (cm) No. of tillers/ plant Grain yield (t/ha) Genotypes Plant height (cm) Panicle length (cm) No. of tillers/ plant Grain yield (t/ha) 08FAN10 93 26.5 12.00 5.25 08FAN10 94.5 25 13.00 5.25 Aanga 92.5 24 11.00 4.4 Aanga 93.25 22.25 13.00 4.44 Bange masino 174.5 24.5 7.00 4.8 Bange masino 173.5 23.38 9.00 4.6 Basmati-370 124 32.5 9.00 3.8 Basmati-370 117.25 29 10.00 3.6 Hansa raj 167.5 23.5 10.00 4.1 Hansa raj 167 22.75 12.00 4.08 Himali 118 24.5 9.00 3.72 Himali 119 22.75 11.00 3.72 Indrabeli 170.5 26 12.00 3.35 Indrabeli 168.25 26.25 12.00 3.35 IR 87751-20-4-42 108 28 9.00 5.27 IR 87751-20-4-42 104 26.85 10.00 5.27 IR 87759-1-2-2-11 104.5 31.5 10.00 5.42 IR 87759-1-2-2-11 102.75 28.6 10.00 5.26 IR 88968-2-1-1-2 107.5 26.5 11.00 4.93 IR 88968-2-1-1-2 102.5 26.7 12.00 4.93 IR67017 95.5 26.5 10.00 4.68 IR67017 93.25 26.5 10.00 4.68 IR70422-95-1-1 96.5 24.5 11.00 3.45 IR70422-95-1-1 97 22.75 11.00 3.28 IR73008-136-22-3 88.5 23 8.00 2.8 IR73008-136-22-3 86.5 22.85 11.00 2.8 IR74052-95-3-2 89.7 25 9.00 3.04 IR74052-95-3-2 87.35 25 12.00 3.29 IR77512-128-21-2 102.5 25.5 11.00 3.59 IR77512-128-21-2 97.25 26 12.00 3.59 IR77512-2-1-2-2 108.5 24 15.00 4.34 IR77512-2-1-2-2 105.5 25.6 14.00 4.34 IR775-39-80-2-22 97.5 26 13.00 4.82 IR775-39-80-2-22 95.5 24 13.00 4.82 Lalka basmati 107 25.5 14.00 3.57 Lalka basmati 107 26 14.00 3.57 NR 10676-B-1-33-3 133 26.5 13.00 5.76 NR 10676-B-1-33-3 130.75 25.75 15.00 5.65 NR 11130-B-B-B3-3 148 25.5 8.00 5.05 NR 11130-B-B-B3-3 146.5 26 9.00 5.02 NR 11133-B-B-B23-2 141.5 30.5 11.00 4.81 NR 11133-B-B-B23-2 140.25 28.5 10.00 4.81 NR 11142-B-B-B9 151.5 29 11.00 4.8 NR 11142-B-B-B9 148.25 28.38 9.00 4.81 NR 11156-B-B-10 144 24.5 7.00 4.65 NR 11156-B-B-10 140.75 23.9 8.00 4.53 NR 11178-B-B-61 164.5 30.5 7.00 5.11 NR 11178-B-B-61 164.5 28.35 8.00 5.25 NR 11182-B-12 134 25.5 13.00 5.42 NR 11182-B-12 133 26 14.00 5.36 NR 11182-B-21 102 21 7.00 4.19 NR 11182-B-21 99.25 21 8.00 4.19 NR 11196-B-3-3 166.5 31 6.00 5.43 NR 11196-B-3-3 167 30.9 7.00 5.18 NR 11281-B-B-11 147 27 7.00 4.78 NR 11281-B-B-11 145 26.95 8.00 4.93 NR 11367-B-B-10 155 29.5 6.00 4.47 NR 11367-B-B-10 153.25 27.45 7.00 4.47 NR 11368-B-B-17 170 28.5 6.00 4.48 NR 11368-B-B-17 169.25 27.63 7.00 4.48 NR 11374-B-B-11 127 24 11.00 4.71 NR 11374-B-B-11 125.25 22.65 12.00 4.71 NR 11410-B-B-9 147.5 25.5 5.00 4.97 NR 11410-B-B-9 148.25 26.1 6.00 5.18 NR10410-89-3-21-1 136 25.5 13.00 5.54 NR10410-89-3-21-1 132.5 26 14.00 5.54 Pokhreli Basmati 160 25.5 11.00 4.2 Pokhreli Basmati 155.75 26 12.00 4.2 Pokhreli Jethobudho 180.5 26.5 6.00 3.56 Pokhreli Jethobudho 176.5 25.38 8.00 3.56 Pokhreli Masino 173.5 28 7.00 3.56 Pokhreli Masino 176.75 25.6 8.00 3.56 Sali dhan 133.5 25 5.00 3.6 Sali dhan 129.25 26.1 7.00 3.35 Sugandha-2 112.2 26 9.00 2.46 Sugandha-2 111.1 24.75 10.00 2.67 Sugandha-3 105.5 25 9.00 4.96 Sugandha-3 101.5 24.5 11.00 4.96 Sunaulo Sughandha 103 26 14.00 2.6 Sunaulo Sughandha 102.75 24.25 15.00 2.45 Grand mean 129.54 26.34 10.00 4.36 Grand mean 127.72 25.61 11.00 4.34 SEM 7.37 2.46 1.88 0.4 SEM 4.47 1.68 2.01 0.27 P value <.001 0.01 <.001 <.001 P value <.001 <.001 <0.001 <.001 CV% 5.69 9.35 19.56 9.21 CV% 4.95 9.29 18.96 8.73 LSD (0.05) 14.97 5 3.86 0.82 LSD (0.05) 8.86 3.33 2.82 0.53 GM: Grand mean, SEM: Standard error of mean, CV: Coefficient of variation, LSD: Least significant difference. GM: Grand mean, SEM: Standard error of mean, CV: Coefficient of variation, LSD: Least significant difference. 3 J. Shrestha et al. Heliyon 7 (2021) e07940 Table 6. Grouping of 40 rice genotypes by Euclidean Method. Cluster1 Cluster 2 Cluster3 Cluster4 Cluster5 Cluster6 IR 87751-20-4-4-2, Bange masino, Basmati-370, IR73008-136-2-2-3, NR 10676-B-1-3-3-3, NR 11130-B-B-B-3-3, Cluster7 NR 11367-B-B-10, IR 87759-1-2-2-1-1, Hansa raj, Himali, IR74052-95-3-2 NR 11182-B-12, NR 11133-B-B-B-23-2, Pokhreli Basmati IR 88968-2-1-1-2, Indrabeli, NR 11374-B-B-11, NR10410-89-3-2-1-1, NR 11142-B-B-B-9, IR67017, NR 11178-B-B-6-1, Sugandha-2 Sali dhan NR 11156-B-B-10, IR70422-95-1-1, NR 11368-B-B-17, NR 11281-B-B-11, IR77512-128-2-1-2, Pokhreli Jethobudho, NR 11410-B-B-9 IR77512-2-1-2-2, Pokhreli Masino IR775-39-80-2-2-2, Lalka basmati, NR 11182-B-21, NR 11196-B-3-3, Sugandha-3, Sunaulo Sughandha ruled by the genotypes' genetic make-up, which is based on the number of internodes and length of internodes (Rahman et al., 2018). The number of tillers per plant varied from NR 11410-B-B-9 (6) to Sunaulo sugandha (15) (Table 5). The diversity in the genetic makeup of the variety is the cause of the variability in the number of effective tillers per plant. Ramasamy et al. (1987) reported a similar result, stating that varietal variation affected the quantity of tillers. Rice grain yield is heavily influenced by tillering ability. Too few tillers result in fewer panicles, whereas too many tillers result in high tiller mortality, undersized panicles, poor grain filling, and reduced grain yield (Peng et al., 1994). Productive tillers are one of the most important yield components, as the final yield is mostly determined by the number of panicles bearing tillers per unit area (Roy et al., 2014). The panicle length ranged from NR 11182-B-21 (21 cm) to NR 11196B-3-3 (30.9 cm) (Table 5). At various trials of rice evaluation in Khumaltar, Lalitpur, Nepal, there was a fluctuation in the number of viable grains per panicle (NPBGRC, 2020). One of the most critical yields determining features is the number of viable grains per panicle. Gravois and McNew (1993) found that full viable grains per panicle had a beneficial direct effect on rice yield. Grain yield ranged from 2.45 t/ha (Sunaulo Sugandha) to 5.65 t/ha (NR10676-B-3-3-3) (Table 5). Rice Data collected on various growths, yield, and yield components were processed by using Excel 2010 and subjected to Analysis of Variance (ANOVA) by using Genstat 13.2. The treatment means were compared by the Least Significant Difference (LSD) test at 5% level (Gomez and Gomez, 1984). The collected data were subjected to multivariable analysis was done using the statistical software packages of Minitab ver.14 (Mohammadi and Prasanna, 2003). The data was submitted to Average Linkage cluster analysis based on mean Euclidean distances and similarity index (Sneath and Sokal, 1973). 3. Results and discussion All evaluated rice genotypes were found highly significant (p < 0.01) for plant height, panicle length, number of tillers/plant, and grain yield (Table 3, Table 4, and Table 5). The plant height varied from IR73008136-2-2-3 (86.50 cm) to Bange masino (173.5 cm) (Table 5). Rasheed et al. (2002) found similar results for plant height variation in rice genotypes. Plant height is an important growth parameter for any crop since it defines or alters yield contributing traits, which in turn gives grain production (Reddy and Redd, 1997). It is a complicated trait that is the result of various genetically controlled elements, most of which are Dendrogram Average Linkage, Euclidean Distance Similarity 45.12 63.41 81.71 100.00 j i i i i 1 0 -2 -2 n ga -1-1 - 1-2 0 17 -2 1 -4 -2 -1 -1 -1-2 a-3 - 2-2 at dh a-2 -3 -3- 2 ino d ho i no r a bel -6 -1 -3- 3 -17 3 70 al a-2 -3 -3 -1 2 -1-1 -11 han -3 -3 -1 1 B-9 B- 9 3-2 -10 - 10 at AN0-2 Aa - 95 8 -2 67 2-B 0-4 2-2 2-1 nd h2 -1 asmhan 6-2 -95 m asob u M asan sa d ra -B -B B-B ati- Himn dh 1-3 2 -B 3-2 B-B li d -B B-B - B- -B- B-2 B-BB- B asm F b 6 a a g R 8 n B - 8 - - a B - 0 - - B 0 8 9-8 42 2 -1 2 I 1 1 1-2 9 -1 6 8 ug 1 2 lk a S u -13 0 52n g e Jeth reli H I 78 - 11 9 68 asm u g -B 11 -8 9 7 4 S -B- 8 1 2- B 41 -B 5 6 6 7 eli 2 S 76 1 0 1 3 3 1 75 5 8 9 S 75 a o 0 8 74 a i h 1 1 13 B 0 12 14 11 -B 1 1 1 3 h r 5 - R70 5 1 7 L u l 3 0 R B rel ok 6 R 41 1 7 7 8 11 R 1 1 3 1 11 R 1 33 1 1 o k 0 R a I I 77 NR 8 8 7 IR N 0 77 I P 1 7 1 h R R R R n R N NR IR IR IR IR R ok R1 N R 1 N NR N 1 1 N N P N Su IR N P N R N N Genotypes Figure 1. Dendrogram of 40 rice genotypes using Euclidean Method. 4 J. Shrestha et al. Heliyon 7 (2021) e07940 Table 7. Cluster mean for four characters of 40 rice genotypes. Variable Cluster1 Cluster2 Cluster3 Cluster4 Cluster5 Cluster6 Cluster7 Grand centroid Plant height 99.71 170.34 118.15 86.92 131.37 144.83 154.5 127.71 Panicle length 25 26.27 24.78 23.92 25.96 26.63 26.72 25.6 No. of tillers/plant 12.00 9.00 11.00 12.00 12.00 8.00 10.00 11.00 Grain yield 4.35 4.97 3.67 3.04 4.87 4.25 4.33 4.34 Masino) and cluster 4 (IR73008-136-2-2-3, IR74052-95-3-2) (83.51) indicating genetic dissimilarity (Table 9). Anandan et al. (2011) and Latif et al. (2011) both found similar results in rice. Yadav et al. (2011), Vennila et al. (2011), and Latif et al. (2011) proposed using distantly placed cluster genotypes in hybridization programs to get a wide spectrum of variation among genotypes (2011). Table 8. Different statistics of Euclidean distance and cluster analysis of 40 rice genotypes. Cluster No. of genotypes Within cluster sum of squares Average distance from centroid Maximum distance from centroid Cluster1 14 390.3 5.04 7.66 Cluster2 8 236.37 5.27 6.57 Cluster3 4 133.67 5.34 7.63 Cluster4 2 3.56 1.33 1.33 Cluster5 4 53.66 3.24 6.16 Cluster6 6 89.06 3.48 5.18 Cluster7 2 15.02 2.74 2.74 4. Conclusion The cluster analysis showed the presence of genetic diversity in the evaluated genotypes. The highest distance between cluster centroids was found in cluster 2 and cluster 4 indicating genetic dissimilarity. Crosses between parents belonging to the most diverse clusters would be expected to show the maximum heterosis. Rice genotypes NR 10676-B-1-33-3 was found the highest yielder followed by NR10410-89-3-2-1-1 and NR 11182-B-12. These genotypes are promising rice genotypes and grain production can be maximized by growing these genotypes. genotypes NR 10676-B-1-3-3-3 (5.65 t/ha) produced the highest yield, followed by NR10410-89-3-2-1-1 (5.54 t/ha) (Table 3). There was also a lot of variation in grain production across the twelve coarse rice genotypes (Zahid et al., 2005). Significant diversity in agro-morphological traits was reported in rice genotypes by Worede et al. (2014), Shrestha et al. (2020b), and Shrestha et al. (2021). The 40 rice genotypes were grouped in 7 clusters based on growth and yield traits (Table 6, Figure 1). Fifty-eight rice varieties grouped into four clusters based on 18 morphological characters in a study by Ahmadikhah et al. (2008). Rahman et al. (2011) also divided 21 rice varieties into five clusters based on 14 physiological traits. Similar results were also reported by Yadav et al. (2011) and Anandan et al. (2011) in rice. Genotypes of cluster 2 had the highest plant height (170.34 cm) and the highest grain yield (4.97 t/ha) whereas genotypes of cluster 4 had the lowest plant height (86.92 cm) and the lowest grain yield (3.04 t/ha) (Table 7). Similar results were obtained by Chakma et al. (2012). The maximum distance of cluster 1 from centroids was 7.66 and the minimum distance of cluster 4 (1.33) (Table 8). Caldo et al. (1996a) used 33 qualitative and quantitative parameters to estimate a range of Euclidean distance ranging from 2.23 to 16.71 with a mean of 7.55 for 78 improved rice genotypes. Caldo et al. (1996b) used 41 attributes to generate Euclidean distance estimates ranging from 3.97-17.38 with a mean of 8.80 in a separate investigation of 81 ancestral lines of Philippines current rice genotypes. Chakma et al. (2012) discovered similar results. Distance between cluster centroids ranged from 9.78 to 83.49 (Table 9). The lowest distance between cluster centroids was found in the cluster 6 and cluster 7 (9.78) indicating genetic similarity and the highest was found in the cluster 2 (Bange Masino, Hansa raj, Indrabeli, NR 11178-B-B-6-1, NR 11368-B-B-17, Pokhreli Jethobudho, Pokhreli Declarations Author contribution statement Jiban Shrestha; Sudeep Subedi; Ujjawal Kumar Singh Kushwaha; Bidhya Maharjan: Conceived and designed the experiments; Performed the experiments; Analyzed and interpreted the data; Wrote the paper. Funding statement This work was supported by National Plant Breeding and Genetics Research Centre, NARC, Khumaltar, Lalitpur, Nepal. Data availability statement Data will be made available on request. Declaration of interests statement The authors declare no conflict of interest. Additional information No additional information is available for this paper. Table 9. Distances between cluster centroids in 40 rice genotypes. 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