In vitro tetraploid induction of the blackcurrant (Ribes nigrum L.) and preliminary phenotypic observations

Abstract

The aim of this study was to develop an in vitro polyploidisation method for the breeding of new improved cultivars of blackcurrant (Ribes nigrum L.). The Polish blackcurrant cultivars 'Gofert' and 'Polares' were used for the experiments. For polyploidisation, shoot explants were incubated for six days in the dark on a modified Murashige and Skoog medium supplemented with 4.5 µM 6-benzylaminopurine (BAP), 0.3 µM gibberellic acid (GA 3) and 0.5 µM indole-3-acetic acid (IAA), containing one of the following antimitotic agents: colchicine, trifluralin, oryzalin or amiprophos methyl. The strongest phytotoxic effects of antimitotic agents were observed for trifluralin (all the explants died). Tetraploids were obtained for both cultivars: 21 for 'Gofert' and 12 for 'Polares', respectively. The higher efficiencies of tetraploid induction were recorded with oryzalin (5 mg L-1), 26.3% and 28.6% for 'Gofert' and 'Polares', respectively; 25.9% with colchicine (125 mg L-1) for 'Polares' and 9.3% with amiprophos methyl (5 mg L-1) for 'Gofert'. In addition, only six (2.4%) homogeneous 'Gofert' tetraploids were selected directly. Instead, the high percentage (30.1%) of mixoploids was detected in this cultivar. All mixoploid shoots were subcultured twice. An additional 15 homogeneous tetraploids were selected based on the flow cytometry analysis from the mixoploid shoot cultures, but only from among those with a predominance of the tetraploid genotype. The polyploidisation efficiency was on average 8.4% for 'Gofert' and 9.2% for 'Polares'. In vitro growth and shoot multiplication of newly obtained tetraploids were very poor in the presence of BAP. Therefore, in order to obtain tetraploid shoots capable of rooting, shoot multiplication was optimized by application of 6-(3-hydroxybenzylamino)purine (meta-topolin). Replacement of BAP with meta-topolin in the medium allowed faster multiplication of the newly obtained tetraploids, which were then rooted in vitro and grown in a greenhouse. The tetraploids differed phenotypically from their diploid counterparts. Detailed measurements were done for 'Gofert' after six months of growing plants in vitro. Compared to diploid plants, tetraploids had shorter shoots, they contained fewer leaves, their leaf shape was different and chlorophyll index was higher.

In Vitro Propagation Method for Production of Phenolic-Rich Planting Material of Culinary Rhubarb ‘Malinowy’

“…During the last decade, meta -topolin has been widely used in micropropagation of many plant species, improving multiplication and rooting efficiency [ 41 , 42 , 43 ]. Our previous observation showed that the shoot of rhubarb ‘Malinowy’ treated with meta -topolin had higher rooting capacity than those cultured in BAP medium before rooting (data not shown).…”

Chromosome Doubling in Genetically Diverse Bilberry (Vaccinium myrtillus L.) Accessions and Evaluation of Tetraploids in Terms of Phenotype and Ability to Cross with Highbush Blueberry (V. corymbosum L.)

“…In our previous studies, we developed methods for the in vitro polyploidisation of daylily [14], apple [15], tulip [16] and blackcurrant [17]. In those methods, the shoots were treated with antimitotic agents such as colchicine, oryzalin, trifluralin and amiprophos methyl (APM).…”