Morphological characterization of clonal rootstocks of apple

Abstract

Identification of clonal rootstocks of apple was carried out to characterize clonal rootstocks based on morphological characters using International Union for the Protection of New Varieties of Plants (UPOV) descriptor during two consecutive years 2016 and 2017. A wide variation was observed among different selections for various morphological traits. A total of 32 UPOV attributes were observed among which 15 traits were found more informative during the course of investigation. Maximum range was observed for number of spines (5.45-9.10) followed by leaf blade width (3.76 - 4.56) while as minimum range was observed for ratio of petiole length to blade length (0.27-.0.28). The phenotypic coefficient of variation and genotypic coefficient of variation was highest for number of spines (27.10% & 22.42%) followed by leaf blade length of tip (24.34% & 12.24%) and lowest for leaf blade length (6.75% & 4.82%). Phenotypic coefficient of variation was slightly higher than genotypic coefficient of variation, which indicates the minor role of environment in the expression of traits under observation.