Reproductive compatibility studies between wild and cultivated strawberries (Fragaria × ananassa) to obtain “bridge species” for breeding programmes

Abstract

The Fragaria genus has become relevant due to worldwide economic importance of the octoploid hybrid F. × ananassa. Interspecific hybridizations are widely employed in breeding programmes to introduce useful characteristics from wild species to cultivated varieties, although many reproductive barriers prevent gene flow between species. Hybrid genotypes that can act as a bridge between related wild species and cultivated strawberry could be useful to overcome those barriers. The aim of this work was to obtain interspecific hybrids of Fragaria and to analyse possible reproductive barriers. In the Banco de Germoplasma de Frutilla‐UNT, crossings were carried out among wild species of Fragaria with different ploidy levels and cultivated strawberry. To confirm hybrid condition of genotypes obtained, histological techniques and microsatellite markers were used. When wild species were crossed with cultivated strawberry in both directions, there was low production of achenes, while in crosses between wild species of Fragaria genus, achene production was very high. The percentage of germination of achenes was high when crossed species had the same ploidy level, and very low or null when they presented different ploidy levels. Although pre‐zygotic incompatibility associated to the degree of domestication and postzygotic barriers related to different ploidy levels of the progenitors were detected, new hybrid genotypes of Fragaria were obtained. These new hybrids could be used as “bridge species” in breeding programmes, since preliminary results showed no incompatibility barriers when they were crossed with Duchesnea indica.

Cross compatibility in intraspecific and interspecific hybridization in yam (Dioscorea spp.)

“…An attempt with an interspecific cross to introgress desired genetic variants among yam species has been reported 16 . However, such effort is often challenged by pre-zygotic and post-zygotic cross-compatibility barriers in most crops 17 – 19 , including the yams 20 , 21 . Although some yam species cross naturally in controlled and wild environments 22 , efforts are necessary to understand the nature of crossing barriers and devise means that facilitate gene flow among yam species to achieve cross-breeding goals.…”

Southern Species From the Biodiversity Hotspot of Central Chile: A Source of Color, Aroma, and Metabolites for Global Agriculture and Food Industry in a Scenario of Climate Change

“…Several crosses of the Chilean strawberry and Fragaria spp have been performed which have been evaluated for the generation of elite genotypes (Hancock et al, 2001;Finn et al, 2013). Recently, new hybrids were successfully obtained by crossing four different F. × ananassa cultivars with F. chiloensis f chiloensis, increasing diversity and facilitating new bridge species for breeding (Luque et al, 2019). The selection from the breeding programe can be facilitated and optimized by the use of molecular techniques (Edger et al, 2019;Oh et al, 2019).…”

“…Recently, new hybrids were successfully obtained by crossing four different F . × ananassa cultivars with F. chiloensis f chiloensis , increasing diversity and facilitating new bridge species for breeding ( Luque et al, 2019 ). The selection from the breeding programe can be facilitated and optimized by the use of molecular techniques ( Edger et al, 2019 ; Oh et al, 2019 ).…”

La tribu Potentilleae (Rosaceae- Rosoideae) en Argentina

“…Schulze-Menz (1964) reconoce 4 subfamilias basándose en los tipos de frutos y las subdivide en tribu y subtribus, y reúne en la tribu Potentilleae a Potentilla, Duchesnea y Fragaria. Hutchinson (1964) y Kalkman (2004) reconocen tribus y no agrupan los géneros en subfamilias, este último incluye en la tribu Potentilleae a Fragaria, Potentilla (Duchesnea) y enfoca el tratamiento en diversos caracteres, tales como, vegetativos, reproductivos, cariológicos, ecológicos y fitoquímicos. Takhtajan (1997) incorpora los primeros estudios filogenéticos moleculares distinguiendo varias subfamilias y tribus e incluye en la tribu Potentilleae a los géneros Pontentilla, Duchesnea y Fragaria.…”

“…Las relaciones filogenéticas, la ubicación taxonómica al género Fragaria dentro de Rosaceae, su posición a nivel de tribu y subtribu, su fusión o no con Potentilla, su denominación como Fragaria o Potentilla, y la determinación del número de especies que comprende dicho grupo, han sido intensamente debatidos por diferentes autores (Staudt, 1962(Staudt, , 1989(Staudt, , 1999(Staudt, , 2008Hutchinson, 1964;Schulze-Menz 1964;Darrow, 1966;Takhtajan 1997;Eriksson et al, 2003;Ontivero et al, 2000;Mabberley, 2002;Potter et al, 2007;Arias, 2007;Kalkman, 2004;Faghir et al, 2018). En general, la mayoría de estos autores, basan sus estudios en especies principalmente del hemisferio norte, de Norteamérica, Alemania y otros países del continente euroasiático, solo en pocos casos consideran algunas especies de Argentina o del hemisferio sur.…”