Morphological characterization of citrus rootstock genotypes

Abstract

Thirty citrus rootstock genotypes representing four species (C. jambhiri, C. limonia, C. pseudolimon and C. macrophylla) were analysed using 79 morphological characters as per the descriptors developed for Citrus by Biodiversity International, Rome, Italy. Out of 79 morphological traits studied, spine shape, twig vestiture (1st year), twig colouration (2nd/ 3rd year), leaf division, leaf lamina attachment, number of petal flower-1 and colour of open flower did not show any variation, while the remaining traits showed variability to considerable extent. The analysis of variance for the thirty nine quantitative traits revealed statistically significant differences for all the characters studied among tested genotypes. The unique morphological markers were identified for particularly five rough lemon, two rangpur lime and an alemow genotype, respectively which can be used as diagnostic plant characters such as obloid fruit shape (AKLRLe 18/2/4), ellipsoid fruit shape (AKLRLe 60/10), attenuate leaf apex (AKLRLe 62/A1), mandarin-like leaflet odour and seedless fruits (AKLRLe 62/U1), sinuate leaf lamina margin and truncate fruit base (AKLRLe 62/U2), greenish albedo colour (AKLRLi 18/7/5), spineless (AKLRLi 18/7/7), dentate leaf margin, presence of petiole wing and round cross section shape of axis (Alemow 1).