|Bohanec, Borut - UN OF LJUBLJANA, SLOVENIA|
|Jakse, Marijana - UN OF LJUBLJANA, SLOVENIA|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 1, 2005
Publication Date: January 21, 2006
Citation: Havey, M.J., Bohanec, B., Jakse, M. 2006. Genetic analyses of gynogenetic haploid production in onion. Proceedings of Haploids in Higher Plants N24. p. 49. Technical Abstract: The production of doubled haploid plants is desirable as an alternative to sexual inbreeding of longer-generation crops. Onion (Allium cepa L.) is a biennial plant and amenable to the production of gynogenic haploids. Although a strong population effect has been observed for gynogenic haploid production, there was no report describing the genetic basis of higher haploid production in onion. We evaluated over years the frequency of haploid production among onion inbreds and identified lines showing significantly (P<0.01) higher production of haploids. The onion inbreds B0223B and B2923B produced the highest mean frequencies of haploids so far reported. Hybrid families from crosses of B2923B with inbreds having relatively low haploid production showed significantly higher haploid production than the low-producing parent and significantly lower haploid production than B2923B. Self pollination of plants from B2923B showing relatively high rates of haploid production generated S1 progenies also producing relatively high frequencies of haploids. Selfed progenies from plant B2923B-6 showed a high mean rate of haploid production and the highest level of haploid production reported for any single onion plant. These results indicate that relatively high gynogenic haploid production for B2923B was quantitatively inherited with dominance towards low production. We intercrossed among onion plants showing relatively high gynogenic haploid production to develop a synthetic population. Random plants from this synthetic produced haploids at higher frequencies than the parental inbreds. Doubled haploid (DH) lines obtained lines B0223B and B2923B were selfed and the progeny was tested for two characters: male fertility and haploid production efficiency. Male fertility was highly variable among 23 viable lines and ranged from 3-98%. Haploid induction frequency of about 19.000 cultured flowers of the second generation DH lines and of synthetic population was tested and results of the gynogenic response will be presented.