Pollen morphology and variability of caprifig (Ficus carica var. caprificus) genetic resources in Turkey using multivariate analysis

Abstract

This research was carried out to determine pollen morphological characteristics of caprifig genetic resources known as gene center Anatolia. In this study, pollens from 24 individuals, including 20 caprifig genotypes sampled from the Adana, Hatay, Kahramanmaraş, Mersin, and Osmaniye provinces in the eastern Mediterranean region, and four standard cultivars from Aydın in the Aegean region of Turkey were collected. Pollen size and shape, exine thickness, exine tissue, polar and equatorial views, numbers of porates and width, and colpus length and width were measured by using light microscopy (LM) and scanning electron microscopy (SEM). Polar length and equatorial diameter of pollens ranged from 9.99 to 12.60 μm and 8.52 to 11.90 μm, respectively. In 13 genotypes, the pollen shape was prolate-spheroidal, while in the others, it was subprolate. The mean number of porates was 1.92 to 2.56, with the double porate being the most common. All studied caprifigs had “scabrate” and “psilate” exine ornamentation. The highest abnormal pollen ratio was found in ‘Ak İlek’ (34.10%), whereas it was lowest in the Osmaniye10 (1.28%). According to the principal component analysis, polar length, equatorial diameter, colpus width, pollen shape, number of porates, porate width, exine thickness, and abnormal pollen ratio were the most important characteristics in the differentiation of caprifig genetic resources. These results showed that pollen morphology can be used to identify caprifigs, select caprifigs for caprification, and determine the paternal individuals for edible fig-breeding programs.