Confirmation of hybridity in DOGR hybrids of onion (Allium cepa L.) using SSR markers

Abstract

Molecular identification and hybrid purity testing in nine
onion hybrids along with their seven parental lines was
conducted at ICAR-Directorate of Onion and Garlic
Research, Rajgurunagar, Pune (Maharashtra). Four out of
ten microsatellite (SSRs- Simple Sequence Repeats) markers
were found to be polymorphic. All four polymorphic markers
revealed polymorphism between the male and female parents
of one or more hybrids and was utilized for their hybridity
testing. ACM016, ACM033 and ACM078 have been
identified as the three diagnostic markers for testing the
genetic purity of all the nine onion hybrids included in this
study viz.; DOGR Hy-1, DOGR Hy-2, DOGR Hy-3, DOGR
Hy-4, DOGR Hy-5, DOGR Hy-6, DOGR Hy-7, DOGR Hy-8
and DOGR Hy-50. These 10 SSR loci amplified a total 28
alleles in 9 hybrids and 7 parents with 2-4 alleles per loci.
The average number of alleles per loci was found to be 2.8.
The highest polymorphism information content (PIC value)
was observed to be 0.7137 for the marker ACM093 and the
three potential markers ACM016, ACM033 and ACM078
with PIC value 0.5874, 0.5949 and 0.6628, respectively were
the best markers that could be used to differentiate the
parental lines and utilized for hybridity testing. This study
showed that SSR are reliable and effective molecular marker
capable of detecting genetic purity of onion hybrids.