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United States Department of Agriculture

Agricultural Research Service

Title: Genetic Analyses of Gynogenetic Haploid Production in Onion

Authors
item Bohanec, Borut - UNIV LJUBLJANA, SLOVENIA
item Jakse, Marijana - UNIV LJUBLJANA, SLOVENIA
item Havey, Michael

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 2004
Publication Date: July 15, 2004
Citation: Bohanec, B., Jakse, M., Havey, M.J. 2004. Genetic analyses of gynogenetic haploid production in onion. Journal of the American Society for Horticultural Science.

Interpretive Summary: Haploids are plants with one-half of the normal number of chromosomes. The production of doubled haploid plants yields uniform inbred lines and is especially 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 haploids from the female (gynogenic) gametes. Although a strong population effect has been observed for gynogenic haploid production, there is no report describing the genetic basis of higher haploid production in onion. The onion inbreds (B0223B and B2923B) produced the highest mean frequencies of haploids so far reported. Plants from B0223B and B2923B with established rates of haploid regeneration were self pollinated and progenies showed relatively high rates. Selfed progenies from plant B2923B-6 showed a high mean rate of haploid regeneration (56.8 ± 14.46%) and, more importantly, the highest level of haploid regeneration (82.2%) reported for any single onion plant. These results indicated that relatively high haploid regeneration, at least for B2923B, was quantitatively inherited with dominance towards low regeneration. We propose that S1 family selection will be an effective method to increase gynogenic haploid production of onion populations. These results will enhance the abilities of public and private onion breeders to efficiently use haploidy to produce uniform inbred lines for the development of superior hybrid cultivars.

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 is 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<0.05) higher regeneration 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 showing relatively low haploid production showed significantly higher haploid production than the low-producing parent and significantly lower haploid production than B2923B. Plants from B0223B and B2923B with established rates of haploid regeneration were testcrossed and/or self pollinated. The F1 family from B1717A-1 x B2923B-3 showed rates of haploid regeneration slightly greater than the low parent (B1717A-1) and significantly less than the high parent (B2923B-3). Self pollination of bulbs from B2923B with high rates of haploid regeneration produced S1 progenies with relatively high rates. Selfed progenies from plant B2923B-6 showed a high mean rate of haploid regeneration (56.8 ± 14.46%) and, more importantly, the highest level of haploid regeneration (82.2%) reported for any single onion plant. These results indicated that relatively high haploid regeneration, at least for B2923B, was quantitatively inherited with dominance towards low regeneration. We suggest S1 family selection as an effective method to increase gynogenic haploid production of onion populations.

Last Modified: 12/22/2014