LACK OF MALE-STERILITY ALLELISM BETWEEN PEACH AND ALMOND

Male sterility is a reproductive abnormality consisting in the plant inability to produce functional pollen.
Male sterility in peach is a monofactorial recessive trait.
The best known male-sterile peach cultivar is ‘J.H. Hale’, which was used in many old breeding programs, transmitting the male sterility allele to a large number of cultivars.
Almond male sterility was discovered in 1975 in the cultivar ‘Rof’. The genetic proximity between peach and almond suggested that almond male sterility gene could be allelic to peach.
A test of allelism was conducted by crossing ‘Rof’ with pollen from a peach derived from the ‘J.H. Hale’ and ‘Maluenda’ cross, thus heterozygous for male sterility.
If male sterility allelism was present between the two species, half of the hybrid progeny would be male sterile and the other half male fertile.
Pollen viability results have shown that these almond x peach hybrids are male fertile, indicating no allelism for male sterility between the two species.