Multi-trait evaluation of tamarind (Tamarindus indica L) clones using MGIDI and classical selection indices

Abstract

Tamarind (Tamarindus indica L.) is a climate resilient and versatile multipurpose fruit tree used in food and medicinal industry.  An unexplored and underutilized tree, instinct that to develop a high productive Tamarind tree with superior nutritional quality requires unfeigned selection on multiple traits of Tamarind. In this study, sixty diverse tamarind genetic resources representing sour, red, and sweet Tamarind clones were evaluated for morphological and biochemical traits. The classical selection method, Smith-Hazel index (Selection Index I) computed with equal weightage and Selection index I, shortlisted the clones of IFGTBST 2, IFGTBST 7, IFGTBRT 18, IFGTBST 1, IFGTBST 3. The selection index II followed the unequal weight-based method, Tamarind clones viz., IFGTBTI 14, IFGTBTI 2, IFGTBTI 1, IFGTBRT 5, IFGTBTI 5 were selected. This contrasting result raised through immense of multicollinearity among the different characters studied in the selection index I. Multi-Trait Genotype-Ideotype Distance Index (MGIDI) were used against traditional selection indices in identifying superior tamarind clones. In MGIDI, high productive clones viz., IFGTBTI-2, IFGTBTI-15, IFGTBTI-1, IFGBTST-3, IFGTBST-1 and IFGTBTI-14 were identified and also deliver the strengths and weaknesses of clones by six different factors (FA). Top ranked selected clones by MGIDI were differed from selection index I, while the common clones of IFGTBTI 14, IFGTBTI 2 and IFGTBTI 1 observed in both selection index II and MGIDI.  However, MGIDI proved superior to classical indices for multi-trait selection, offering a robust and accurate tool for breeding programs to select high-yielding, nutritionally superior Tamarind clones.