Production and cytogenetic characterization of intertribal somatic hybrids between Brassica napus and Isatis indigotica and backcross progenies

Abstract

Intertribal somatic hybrids between Brassica napus (2n = 38, AACC) and a dye and medicinal plant Isatis indigotica (2n = 14, II) were obtained by fusions of mesophyll protoplasts. From a total of 237 calli, only one symmetric hybrid (S2) and five asymmetric hybrids (As1, As4, As6, As7 and As12) were established in the field. These hybrids showed some morphological variations and had very low pollen fertility. Hybrids S2 and As1 possessed 2n = 52 (AACCII), the sum of the parental chromosomes, and As12 had 2n = 66 (possibly AACCIIII). Hybrids As4, As6 and As7 were mixoploids (2n = 48-62). Genomic in situ hybridization analysis revealed that pollen mother cells at diakinesis of As1 contained 26 bivalents comprising 19 from B. napus and 7 from I. indigotica and mainly showed the segregation 26:26 at anaphase I (AI) with 7 I. indigotica chromosomes in each polar group. Four BC(1) plants from As1 after pollinated by B. napus resembled mainly B. napus in morphology but also exhibited some characteristics from I. indigotica. These plants produced some seeds on selfing or pollination by B. napus. They had 2n = 45 (AACCI) and underwent pairing among the I. indigotica chromosomes and/or between the chromosomes of two parents at diakinesis. All hybrids mainly had the AFLP banding patterns from the addition of two parents plus some alterations. B. napus contributed chloroplast genomes in majority of the hybrids but some also had from I. indigotica. Production of B. napus-I. indigotica additions would be of considerable importance for genome analysis and breeding.

A Novel Cytoplasmic Male Sterility in Brassica napus (inap CMS) with Carpelloid Stamens via Protoplast Fusion with Chinese Woad

“…The plants of inap CMS grew more slowly and flowered later almost 2 weeks than Huashuang 3 in Wuhan, but they show no leaf chlorosis, likely for they maintained the chloroplast genetic component from Huashuang 3 (Du et al, 2009; Kang et al, 2014). But death of flower buds occurred at the initial stage of flowering, and later the flower buds developed and opened normally.…”

“…The most mitochondrial genes of inap CMS were found to originate from I. indigotica ( Table 4 ), which was likely caused by the asymmetric fusion to produce the hybrids (Du et al, 2009). The protoplasts of B. napus were treated by 3 mM iodoacetate (IOA), and those of I. indigotica were irradiated with UV (Du et al, 2009).…”

“…Huashuang 3 (2 n = 38, AACC) and I. indigotica Fort. (Chinese woad, 2 n = 14, II) was previously produced by protoplast fusion (Du et al, 2009). The backcrossed progenies with the same chromosome number and complement as B. napus were male sterile due to the development of carpelloid stamens (Kang et al, 2014).…”

“…In our previous study, the intertribal somatic hybrids between B. napus and Isatis indigotica Fort. (Chinese woad) of the Isatideae tribe within the Brassicaceae family were obtained and backcrossed successively to B. napus (Du et al, 2009; Kang et al, 2014), resulting in the development of one novel B. napus CMS line with carpelloid stamens (named as inap CMS). Herein, the histological and genetical characterizations of inap CMS were described, together with the mitochondrial rearrangements.…”

Production and genetic characterization of somatic hybrids between leaf mustard (Brassica juncea) and broccoli (Brassica oleracea)

“…Somatic hybridization provides a means to overcome sexual incompatibility and has been used to obtain many intra-and inter-specific, inter-generic, inter-tribal, and even inter-familial somatic hybrids (Waara and Glimelius 1995;Glimelius 1999;Chen et al 2007;Tu et al 2008;Zhao et al 2008;Du et al 2009). This technology has produced not only intra-generic hybridizations but also inter-generic hybrids and cybrids (Dudits et al 1987), allowing the transfer of various desirable traits from parents to hybrids and cybrids (Menzel et al 1987;Chatterjee et al 1988;Jourdan et al 1989;Walters et al 1992;Menke et al 1996;Arumugam et al 2000;Ren et al 2000;Hu et al 2002a, b).…”