the consonant rebound of inbreeding and fluorescent microscope inspections beside s-genotyping of 93 apple (malus domestica l.) cultivars

Objective: it is unavoidable to identify the level of self-compatibility of cultivars (cvs) in heterozygote species, including apples for different purposes such as monoclonal orchards, fuggy climate regions, and particularly in breeding programs. this research aimed to investigate the presence of self-compatibility in the apple cvs/genotypes under study by measuring the fsp at field conditions, ptg under fluorescent microscopy, and s-genotyping.methods: a sequential seven-year field screening for self-compatibility levels of 93 apple cvs was performed through three inbreeding methods. nine flowering shoots were assessed by counting the flowers and fruitlet numbers at four biological growth stages compared to the free-pollinated shoots. further inspections were achieved on the pollen tube growth (ptg) trend of the inbred ovaries, taken from the cuttings obtained at field and room conditions, related to the 33 cvs with higher levels of self-compatibility.results: the field assessment led to identify 47 cvs, carrying different levels of self-compatibility. the recorded fruit set percent overlapped with the pollen tube number and ptg rates. it was confirmed that the self-pollinated varieties morabbaei, mashhad, and bel du pontoise, and the promising genotype iri6, which gained the highest score (5) for ptg till the ovary center, were assumed as fully self-compatible. on the other hand, molecular s-genotyping use of the allele-specific primers on 25 cvs led to the detection of some self-incompatibility alleles, which were previously reported in the other apple cvs, while in some others only a unique allele was observed.conclusion: morabbaei, mashhad, and bel du pontoise cultivars, and also the promising genotype iri6, were recognized as self-compatible genotypes suitable for turbulent climates. although s-genotyping detected some self-incompatibility alleles, however, more research is needed to attribute the direct relation of the studied characteristics with the detected s-alleles.