Arabidopsis thaliana-derived resistance against Leptosphaeria maculans in a Brassica napus genomic background

Plants were regenerated from mesophyll protoplasts of Ipomoea cairica L., a wild relative of sweetpotato (Ipomoea batatas (L.) Lam.), and somatic hybrids between I. cairica L. and sweetpotato cv. Xushu 18 were obtained by PEG-mediated method. I. cairica L. protoplasts were isolated from the leaves of in vitro grown plants and cultured in a modified MS medium containing 0.05 mg l -1 2,4-D and 0.5 mg l -1 kinetin. Nine weeks after plating, the obtained small calluses up to about 2 mm in diameter were transferred to solid MS medium supplemented with 0.05 mg l -1 2,4-D and 0.5 mg l -1 kinetin for callus proliferation. Three weeks after transfer, the calluses were transferred to MS medium supplemented with 0-1.0 mg l -1 IAA and 1.0-3.0 mg l -1 BAP and further to hormone-free MS medium for plant regeneration. The frequencies of calluses forming plants ranged from 6.0% to 41.3% based on the different concentrations of IAA and BAP, and 2.0 mg l -1 BAP gave the highest regeneration frequency of protoplast-derived calluses in I. cairica L.. The regenerated plants, when transferred to soil, showed 100% survival. No morphological variations were observed. Mesophyll protoplasts of I. cairica L. were fused with protoplasts isolated from embryogenic suspension cultures of Xushu 18 by PEG-mediated method. The fused products were cultured with the best protoplast culture system of I. cairica L.. Finally, 114 plants were produced from 63 of the 182 calluses derived from the fused protoplasts, and 46 plants of them were confirmed to be somatic hybrids through peroxidase isozyme, RAPD, morphological and cytological analyses.

Section: Introductionmentioning

confidence: 99%

Regeneration of plants from Ipomoea cairica L. protoplasts and production of somatic hybrids between I. cairica L. and sweetpotato, I. batatas (L.) Lam.

Guo

Liu

Zhai

et al. 2006

“…In contrast, many intergeneric, intertribal or interfamilial somatic hybrids have been obtained via protoplast fusion and some of them were fertile and therefore can be used as bridging materials for breeding Hoffmann, 1978, 1980;Hinnisdaels et al, 1991;Ohgawara et al, 1991;Babiychuk et al, 1992;Gavrilenko et al, 1992;Fahleson et al, 1994b;Forsberg et al, 1994Forsberg et al, , 1998aSkarzhinskaya et al, 1996;Nothnagel et al, 1997;Vlahova et al, 1997;Grosser et al, 1998;Bohman et al, 1999Bohman et al, , 2002Hu et al, 2002a;Xia et al, 2003). In addition, many hybrids were successfully established in some species with special reproductive features.…”

Section: Application Of Somatic Hybridization To Crop Genetic Improvementioning

confidence: 92%

“…Somatic hybridization could play a role in transfer of resistance from divergent relatives into crop plants. For example, resistance to diseases caused by bacterium, fungus or nematode has been transferred from donor species to the cultivated crops by protoplast fusion (Lelivelt and Krens, 1992;Lelivelt et al, 1993;Forsberg et al, 1994;Hansen and Earle, 1997;Sigareva and Earle, 1999b;Bohman et al, 2002;Hu et al, 2002a;Furuta et al, 2004). Somatic hybrids between Japanese radish and cauliflower showed resistance to clubroot, a serious disease in cauliflower.…”

Section: Transfer Of Resistance To Biotic and Abiotic Stressesmentioning

confidence: 96%

“…For example, the backcross progenies of the somatic hybrids between rapeseed and Sinapsis arvensis or A. thaliana showed significantly higher resistance to blackleg or stem canker than rapeseed, indicating stable inheritance of disease resistance from the somatic hybrid to the progenies (Bohman et al, 2002;Hu et al, 2002a). In addition, tolerance to herbicide, salt, drought, heat and cold has also been transferred from the desirable donors to the cultivated species via somatic hybridization (Louzada et al, 1993;Hossain et al, 1994;Sherraf et al, 1994;Begum et al, 1995;Vazques-Thello et al, 1996;Yemets et al, 2000;Arumugam et al, 2002;Xia et al, 2003).…”

Section: Transfer Of Resistance To Biotic and Abiotic Stressesmentioning

confidence: 97%

See 1 more Smart Citation

Intergeneric somatic hybridization and its application to crop genetic improvement

Liu

Deng

2005

112

Related or distant species of cultivated crops are a large pool of many desirable genes. Gene transfer from these species through conventional breeding is difficult owing to post-and pre-zygotic sexual incompatibilities. Somatic hybridization via protoplast fusion is a possible alternative for gene transfer from these species to cultivated crops. Since the early days of somatic hybridization many intergeneric somatic hybrids have been developed through symmetric fusion, asymmetric fusion and microfusion. Somatic hybrids are mainly selected by using markers such as specific media or fusion parents with special features, biochemical mutants, antibiotic resistance and complementation strategy. The hybridity of the regenerants is determined based on morphological, cytological and molecular analysis. The inheritance patterns of nuclear and cytoplasmic genomes in the somatic hybrids are diverse. Nuclear DNA from both fusion parents co-exists congruously in some hybrids with translocation and rearrangement of chromosomes, but spontaneous elimination of chromosomes from either or both fusion parents has been observed very often. In asymmetric fusion, chromosome elimination is an important issue that is a complicated process influenced by many factors, such as irradiation dose, phylogenetic relatedness, ploidy level of fusion parent and regenerants. As for chloroplast genome, uniparental segregation is mainly detected, though co-existence is also reported in some cases. The mitochondrial genome, in contrast to chloroplast, undergoes recombination and very frequent rearrangements. Somatic cell fusion has potential applications for crop genetic improvement by overcoming sexual incompatibility or reproductive barriers, and by realizing novel combinations of nuclear and/or cytoplasmic genomes.

“…Somatic hybridization has been successfully used to transfer desired characteristics from wild relatives to cultivated plants in many crops (Lelivelt et al 1993;Hansen and Earle 1997;Yemets et al 2000;Bohman et al 2002;Hu et al 2002;Yan et al 2004;Thieme et al 2008). So far, some interspecific somatic hybrids have been produced by polyethylene glycol (PEG) or electrically induced fusion between sweetpotato and its wild relatives, but all these somatic hybrids are not capable of producing storage roots, which limits the use of these somatic hybrids in sweetpotato improvement (Liu et al 1992Belarmino et al 1993;Zhang et al 2002;Guo et al 2006).…”

mentioning

confidence: 97%

Development and evaluation of a storage root-bearing sweetpotato somatic hybrid between Ipomoea batatas (L.) Lam. and I. triloba L.

Yang

Guan

Zhai

et al. 2009

Development and evaluation of a storage root-bearing sweetpotato somatic hybrid between Ipomoea batatas (L.) Lam. and I. triloba L.Abstract A storage root-bearing somatic hybrid was produced for the first time by protoplast fusion between sweetpotato (Ipomoea batatas (L.) Lam.) cv. Kokei No. 14 and its wild relative I. triloba L. Protoplasts isolated from embryogenic suspension cultures of Kokei No. 14 were fused with petiole protoplasts of I. triloba L. using polyethylene glycol-mediated protocol. Fusion products were cultured in a modified Murashige and Skoog medium containing 0.05 mg l -1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg l -1 kinetin. A total of 176 plants were obtained from 42 out of 134 calluses derived from fused protoplasts, and 91 of these plants were confirmed to be somatic hybrids through peroxidase isozyme, random amplified polymorphic DNA, amplified fragment length polymorphism, and cytological analyses. Upon transfer into soil and grown in the greenhouse and then to the field, 100% survival was observed. A single plant, designated KT1, was found to produce storage roots. Genomic in situ hybridization analysis confirmed presence of chromosomes from both parents and recombinant chromosomes in KT1. Drought tolerance, dry matter content, soluble sugar content, and fertility of this somatic hybrid were evaluated for potential use in sweetpotato breeding.