Diversity analysis in half and full sib progenies of guava Psidium guajava L using genetic markers

Abstract

A study was conducted using 266 guava half and full-sib progenies at the Dr.YSRHU-College of Horticulture, Dr.Y.S.R. Horticultural University, Anantharajupeta during the years 2020 2022 to know the diversity among half and full-sib progenies of guava (Psidium guajava L.) using genetic markers. Hybridization of promising parents with desired characteristics was helpful to obtain better progenies. Both half and full sib progenies showed variation regarding qualitative and pseudo-qualitative traits for morphological characters. Segregation of parents resulted in the production of differently shaped fruits and variation in the colour of the pulp. newlineThe variability is explained by the wide range of coefficients of variation with regard to the vegetative attributes like stem circumference, leaf length, leaf width and their ratio among the guava progenies. The reduction of photosynthetic rate, stomatal conductance, transpiration rate, and internal CO2 during the reproductive stage was greater than the vegetative stage. Regarding fruit characters, among early-bearing progenies, only H1-23, OP-13 and OP-108 produced fruits with a prominent neck. Broad, round-shaped fruits were obtained from H3-15 and H3-35. Except for H1-2, H1-9, H1-22, H1-28, H1-34, H1-43, H1-46, H1-48, H2-13, H5-2, H5-18, OP-39, OP-70, OP-83, OP-91, OP-97, OP-103, OP-115 and OP-118 which produced red pulp fruits, the majority of the fruits produced by the progenies had white pulp colour. newlineMedium Genotypic Coefficient of Variation (GCV) and Phenotypic Coefficient of Variation (PCV) were observed in stem circumference, fruit length and fruit width. Fruit characteristics like length of stalk, thickness of outer pulp, fruit weight, fruit volume, number of fruits per plant, number of seeds per 100g fruit, 100 seed weight, and seed hardiness recorded high GCV and PCV. High heritability was found in fruit quality attributes viz., total soluble solids, acidity, newlinexviii newlineascorbic acid content, shelf life and fruit firmness. The GAM (Genetic Advances as per cent of mea