Citrus asymmetric somatic hybrids produced via fusion of gamma-irradiated and iodoacetamide-treated protoplasts

Abstract

-The objective of this study was to produce citrus somatic asymmetric hybrids by fusing gamma-irradiated protoplasts with iodoacetamide-treated protoplasts. Protoplasts were isolated from embryogenic suspension cells of grapefruit (Citrus paradisi Macfad.) cultivars Ruby Red and Flame, sweet oranges (C. sinensis Osbeck) 'Itaboraí', 'Natal', Valencia', and 'Succari', from 'Satsuma' (C. unshiu Marcow.) and 'Changsha' mandarin (C. reticulata Blanco) and 'Murcott' tangor (C. reticulata x C. sinensis). Donor protoplasts were exposed to gamma rays and receptor protoplasts were treated with 3 mmol L -1 iodoacetamide (IOA), and then they were fused for asymmetric hybridization. Asymmetric embryos were germinated, and the resulting shoots were either grafted onto sour orange, rough lemon or 'Swingle' (C. paradisi x Poncirus trifoliata) x 'Sunki' mandarin rootstock seedlings, or rooted after dipping their bases in indol-butyric acid (IBA) solution. The products were later acclimatized to greenhouse conditions. Ploidy was analyzed by flow cytometry, and hybridity was confirmed by amplified fragment length polymorphism (AFLP) analysis of plantlet DNA samples. The best treatment was the donor-recipient fusion combination of 80 Gy-irradiated 'Ruby Red' protoplasts with 20 min IOA-treated 'Succari' protoplasts. Tetraploid and aneuploid plants were produced. Rooting recalcitrance was solved by dipping shoots' stems in 3,000 mg L -1 IBA solution for 10 min.

Asymmetric Somatic Plant Hybridization: Status and Applications

“…Similar optimal IOA concentration were found in Musa [41]. Lower IOA concentrations (0.5 mM) stopped growth of Gossypium hirsutum protoplasts, whereas 3 mM and 7.5 mM IOA were required to stop cell proliferation in Citrus [42] and Bupleurum scorzonerifolium [43], respectively.…”

The effects of cytokinin and plating density on protoplast culture of sunflower

“…Protoplast is a naked plant cell and it can form new wall and dedifferentiate under in vitro, becoming totipotent (Costa et al 2018). Protoplast fusion was developed and successfully used to transfer cytoplasmic traits in brassica (Liu et al 1996), tobacco (Zubko et al 2003), citrus (Bona et al 2009;Xu et al 2006), chicory (Varotto et al 2001) and celeriac (Bruznican et al 2021) etc. Development and regeneration in vitro of sunflower usually depend on genotypes, culture conditions and tissue sources (Cravero et al 2012;Dagustu 2018;Davey et al 2005;Jie et al 2011;Kativat et al 2021;Radonic et al 2008;Rákosy-Tican et al 2007).…”