Diversity analysis of Chittamruthu [Tinospora cordifolia (wild)] ecotypes of southern districts of Kerala

Abstract

The study titled "Diversity analysis of Chittamruthu [Tinospora cordifolia (Willd.)] ecotypes of Southern districts of Kerala" was conducted at the Department of Plantation, Spices, Medicinal and Aromatic Crops, College of Agriculture, Vellayani during 2021-2023. The study aimed to assess morphological, phytochemical and genetic variation in Chittamruthu using SSR markers. Chittamruthu ecotypes, 27 nos. were identified from different locations in the ten distinct Agro-Ecological Units (AEUs) of Southern Kerala viz., AEU 1 (Chirayinkeezhu, Kottiyam, Kundara), AEU 3 (Suranad), AEU 4 (Thiruvalla, Ambalappuzha), AEU 5 (Mala), AEU 8 (Neyyattinkara, Kalliyoor, Kattakkada), AEU 9 (Ponkunnam, Mylom, Vembayam, Pala), AEU 12 (Vannapuram, Nanniyod, Vellanad), AEU 14 (Kulathuppuzha, Nemmara, Vellathooval, Nelliyambathi, Adimali, Vithura), AEU 16 (Kattappana, Pambadumpara, Shanthanpara) and AEU 17 (Kanthalloor). Chittamruthu stem is being used by the localites for curing kidney-related ailments in Chirayinkeezh, Thiruvananthapuram. Chittamruthu stem powder could improve digestion as opined by the localites in Kottiyam, Kollam. Amrithasatwa is a unique Chittamruthu preparation revealed by a traditional medicinal practitioner in Suranad, Kollam for treating acidity. In addition, local use of Chittamruthu for addressing health issues viz., menstrual irregularities, post-partum care, managing rheumatic fever, diabetes, joint pain, arthritis and dengue fever were documented. Chittamruthu ecotypes showed significant morphological variations in stem diameter, density of lenticels, petiole length, leaf length, leaf breadth and leaf area. Ecotype (T6) collected from Ambalappuzha (AEU 4) recorded the highest stem diameter (2.00 cm), petiole length (12.60 cm), leaf area (153.78 cm2), laminar length (12.37 cm) and laminar breadth (12.67 cm). The highest density of lenticels was observed in the ecotype (T14) obtained from Pala (AEU 9). Genetic variation among the 27 Chittamruthu ecotypes were assessed using ten SSR markers viz., TCTSSR 59, TCTSSR 104, TCTSSR 126, TCTSSR 92, TCTSSR 37, TCTSSR 18, TC 23, TC 8, TC 9, and TC 1. Among these primers, TCTSSR 104, TCTSSR 92, TC 23, TCTSSR 59, TCTSSR 126 and TC 1 exhibited polymorphism, while the remaining four were monomorphic. TCTSSR 104 recorded the highest Polymorphism Information Content (PIC) value (0.49). A dendrogram developed using NTSYS-pc software demarcated the 27 Chittamruthu ecotypes into 96 seven clusters at a similarity coefficient, 0.86. Cluster I comprised of 20 ecotypes, Cluster II to VI were comprised of one ecotype each and Cluster VII comprised of two ecotypes. A single representative ecotype from each cluster was used for phytochemical diversity analysis. Vellanad ecotype (AEU 12) recorded the highest total alkaloid (183.96 μg AE mg -1) and total flavonoid (162.62 μg QE mg-1) content. The highest total phenol content (55.21 μg GAE mg -1), total saponins (99.29 μg DE mg-1) and cardiac glycosides (42.09 μg DE mg -1) were recorded by Chirayinkeezhu (AEU 1), Kulathuppuzha (AEU 14) and Nemmara (AEU 14) ecotypes, respectively. The study revealed that 27 Chittamruthu ecotypes collected from ten distinct AEUs from the Southern districts of Kerala showed significant diversity in their morphological, molecular and phytochemical characteristics. Ambalappuzha ecotype (AEU 4) recorded superior morphological characteristics. Molecular diversity analysis using SSR markers had demarcated the 27 Chittamruthu ecotypes into seven genetically diverse clusters. Pharmacological properties of Chittamruthu are mainly attributed to alkaloids. In this study, Vellanad ecotype (AEU 12) is identified as potential alkaloid yielding Chittamruthu (183.96 μg AE mg -1).