Pak. J. Bot., 52(2): 575-580, 2020. DOI: http://dx.doi.org/10.30848/PJB2020-2(2) ASSESSMENT OF GENETIC DIVERSITY IN PEA (PISUM SATIVUM L.) LANDRACES BASED ON PHYSICO-CHEMICAL AND NUTRITIVE QUALITY USING CLUSTER AND PRINCIPAL COMPONENT ANALYSIS UZMA ARIF 1 , MUHAMMAD JAMIL AHMED 1 , MALIK ASHIQ RABBANI 2* AND AYAZ AHMED ARIF 1 1 Department of Horticulture, University of The Poonch, Rawalakot, AJK 2 Plant Genetic Resources Institute, National Agricultural Research Centre, Islamabad, Pakistan *Corresponding author’s email: rabbani316@yahoo.com Abstract Field pea (Pisum sativum L.) is an important protein-rich pulse crop produced globally. Genetic and environmental factors lead to a variation in protein content and also influence the quality of seed of dry pea ( Pisum sativum L.). The area and production for dry peas are increasing but knowledge is lacking on how the pea landraces differ in the seed quality. The purpose of the present study was biochemical characterization of 46 pea landraces in order to evaluate the moisture content, fat, fiber, protein, ash, phenolic content, carbohydrates, pH, chlorophyll content and TSS. The data obtained after biochemical analysis were subjected to statistical analysis. The cluster analysis indicated the probable association within 46 pea landraces. Landraces L7, L13, L19, L25, L26, L27, L30 and A43 were showing variation in term of analyzed biochemical traits. Correlation coefficients among all the biochemical traits were computed. Ash content was showing maximum positive and highly significant correlation with moisture content (0.583 ** ), phenolic content (0.76 ** ) and fat (0.371 ** ). Fiber was showing highly significant and positivele correlation with three characters which were: protein (0.455 ** ), total soluble solid (0.437 ** ), and fat (0.399 ** ). Positive and highly significant association was found among carbohydrate and pH (0.418 ** ). Fat content was showing positive and significant correlation with moisture content (0.316 * ), protein (0.313 * ) and total soluble solid (0.312 * ), respectively. These findings can be used to guide future breeding studies and germplasm management of these pea landraces. Based on our findings, it is recommended that pea landraces which performed well in the experiment and bear bright future prospects should be considered in designing future hybridization programs to elucidate the correlation among various biochemical aspects at molecular level among different pea genotypes. Key words: Diversity, Principal component analysis, Cluster analysis, Pea landraces. Introduction Pea (Pisum sativum L.) is grown as leguminous crop in many regions of the world. Its production ranks fifth in the world after soybean, peanut, drybean, and chickpea. Field pea is mainly used as a protein source, as it has a relatively rich and unique protein profile, different from other natural protein sources (Anon., 2010). Pea proteins are esteemed for its high digestibility (90-95%) and havefewer allergenic- responses and no health controversy also. It is gluten- free, little in the sulfurous amino-acids (cysteine and methionine), more in lysine, an important amino -acid for human health (Pownall et al., 2010). Field peas have 23% protein, on the other hand novel pea genotypes have around 30% protein and advanced pea lines with 30% protein (Bing, 2007, 2010a, 2010b, 2012). Dried-peas are frequently used within soup and also directly consumed (Nawab et al., 2008). The best pH ranged for pea production is 5.5 -7.0. The fat material of peas is normally very low with no cholesterol at all (Anon., 2015). Most important part of beans, peas, and lentils is fiber. Fiber is an ingredient of plant foods that cannot be digested. Legumes contain 7 g of dietary fiber and good sources of various vitamins and minerals, such as folate, Fe, K, and mg (Anon., 2015). Peas are complete source of nutrition in light of the fact that their grains are full of protein (27.8%), complex-sugars (42.65%), nutrients, minerals, fibers and antioxidant -compounds (Urbano et al., 2003; 2005). It ranges from 15.5-39.7% (Davies et al., 1985; Bressani & Elias, 1988). Fresh peas have per 100 g: 44 calories, 75.6% water, 6.2 g protein, 0.4 g fat, 16.9 g carbohydrate, 2.4 g crude-fiber and 0.9 g ash, while dried peas contain: 10.9% water, 22.9% protein, 1.4% fat, 60.7% starch, 1.4% crude-fiber, and 2.7% ash (Duke, 1981; Hulse, 1994). TSS is the most essential parameter that helps to designate sugariness of fresh and processed horticultural food yield. Peas contain large quantities of water in proportion to their weight (Xue & Yang, 2009). They generally contain 90-96% water. Water content has important effect on pea’s quality characteristics (Liu et al., 2007). Keeping in view the biochemical importance of peas, the present study was conducted to investigate genetic diversity through physico-chemical and quality related traits in various pea landraces. Material and Methods The present study was conducted during 2015-2016 at University of the Poonch, Rawalakot. The landraces were collected from different locations of district Poonch (Banjosa, Devi Gali, Jandali, Dhoke, and Rawalakot), Bagh (Harigal, Sudhan Gali, Mallot, and Dirkot), Sudhnoti (Trarkhal, Mang, Bloch, and Plandari), Mirpur and NARC (PGRI) Islamabad. Forty six landraces of field pea were used to assess the biochemical diversity in pea germplasm (Table 1).