Variation in Seedling Growth of Tamarindus indica (L.): A Threatening Medicinal Fruit Tree Species in Bangladesh

Seedling growth is a precondition for conservation and sustainable use of genetic resources which depends upon understanding of breeding system, genetic inconsistency, and evolutionary forces in forest tree improvement. The aim of this study was to determine variation in seedling growth and age-age correlations of Tamarindus indica at population level in Bangladesh. The study revealed significant ( ) differences of seasonal variation in seedling growth. Height and collar diameter growth showed significant ( ) positive correlation with mean monthly rainfall. The study also revealed significant difference ( ) of seedling growth among T. indica population. PCA illustrated rainfall, height growth, and diameter growth as the main characters in this study which defined drought as an additive character for this species. Cluster analysis of similarity showed how seedlings from 22.67°N latitude (origin) separated from others. An increasing trend of age-age correlation was identified in both cases of shoot height and diameter growth. The study concluded that seed collection for either ex situ conservation or seedling production can be done from 22.67°N latitude as seedlings from that area performed better than others, and early clonal selection of T. indica can be done at the age of 9 months. 1. Introduction Tamarindus indica (Linn), a multipurpose, leguminous, tropical evergreen fruit tree species of Caesalpiniaceae subfamily, is indigenous to Africa (Madagascar, Zimbabwe, Chad, Sudan, Nigeria, Uganda, and Kenya) and Southern Asia which plays an important role in ecological and economic services [1–4]. Domestication of this species in south-east Asian countries like India, Sri Lanka, Nepal, Pakistan, and Bangladesh is very advanced [3–5] and it is also practiced in Australia, Brazil, Mexico, Philippines, America, and Jamaica [1]. T. indica is found in semiarid areas of tropics up to 1500？m above sea level where annual rainfall is more than 1500？mm and can grow well on poor soil especially in degraded areas [4, 6]. The most important product of T. indica is the pulp of the fruit, and this species is well accepted for its soft, juicy, appetizing, tasty, delicious fruit because of its brown, sticky, sour-sweet pulp generally used as an ingredient in curries, chutneys, preserves, pickles, sherbets, and beverages in a variety of dishes and drinks in household as well as in confectionery [1, 3, 4, 7]. The fruits of this species contain high levels of protein, carbohydrate, minerals (potassium, phosphorus, and calcium), and iron with low amount of water content [8].