scholarly journals In vitro Induction of Banana Autotetraploids by Colchicine Treatment of Micropropagated Diploids

1992 ◽  
Vol 40 (6) ◽  
pp. 887 ◽  
Author(s):  
SD Hamill ◽  
MK Smith ◽  
WA Dodd

Alternative breeding strategies, based on colchicine-induced autotetraploids, have been proposed as a means of introducing disease resistance into banana breeding programs. This paper describes techniques for the in vitro induction of banana autotetraploids by the use of colchicine on cultured explants. The technique can be readily applied and large numbers of autotetraploids produced. The optimum treatment involved immersing shoot tips in a 0-5% w/v colchicine solution for 2 h under aseptic conditions. Dimethyl sulfoxide (DMSO) was applied with the colchicine treatments to increase cell permeability and so absorption of colchicine, resulting in the optimum treatment unchanged at 0-5% colchicine, but including the addition of 2% v/v DMSO. Of the shoot tips treated over 30% were induced to the autotetraploid level. Methods for in vitro selection of induced tetraploids from treated diploid plantlets were also developed. Tetraploid plants were more robust with thicker pseudostems, roots and broader leaves than diploids and they could be selected on these morphological characteristics. Mean stomatal lengths of diploid banana plants growing in vitro were significantly smaller (16-0 mum) than the tetraploids (26.9 mum) and were used as a more reliable indicator of ploidy than morphological criteria alone. A root tip squash technique using carbol fuchsin was developed for positive confirmation of ploidy change by chromosome counts- Although chimerism and reversion to the diploid form occurred, it was not considered a problem because of the large number of autotetraploids induced. Stable autotetraploids were recovered and established in the field and were characterised by their large, drooping leaves and thick pseudostems. They have retained these characteristics for more than 3 years in the field.

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Meiya Li ◽  
Bin Ding ◽  
Weipeng Huang ◽  
Jieli Pan ◽  
Zhishan Ding ◽  
...  

Bletilla striata (Thunb.), an ornamental and medicinal plant, is on the list of endangered plants in China. Its pseudobulb is abundant in polysaccharide and has been used for centuries as a herbal remedy. However, a recent rise in demand has placed it at risk of extinction, and therefore, research on its propagation and genetic improvement is essential. Since polyploids tend to possess advantageous qualities, we incubated B. striata seeds with colchicine with the aim of creating tetraploid plantlets. Aseptic seeds treated with 0.1% colchicine for 7 days showed the highest tetraploid induction rate of 40.67 ± 0.89%. Compared with the wild-type, the tetraploids could be identified by their morphological characteristics including larger stomata at a lower density, larger leaf blades, and a thicker petiole. Contents of polysaccharide and phenolic compounds were also determined in the tetraploid pseudobulbs, revealing significantly higher values than in the wild-type. In vitro colchicine treatment can therefore be used to successfully produce B. striata tetraploids with superior pseudobulbs.


2004 ◽  
Vol 44 (10) ◽  
pp. 1065 ◽  
Author(s):  
M. K. Smith ◽  
S. D. Hamill ◽  
B. J. Gogel ◽  
A. A. Severn-Ellis

Ginger autotetraploids were produced by immersing shoot tips in a 0.5% w/v colchicine, 2% v/v dimethyl sulfoxide solution for 2 h. Stomatal measurements were used as an early indicator of ploidy differences in culture with mean stomata length of tetraploids (49.2 μm) being significantly larger than the diploid (38.8 µm). Of the 500 shoot tips treated, 2% were characterised as stable autotetraploid lines following field evaluation over several seasons. Results were confirmed with flow cytometry and, of the 7 lines evaluated for distinctness and uniformity, 6 were solid tetraploid mutants and 1 was a periclinal chimera. Significant differences were noted between individual tetraploid lines in terms of shoot length, leaf length, leaf width, size of rhizome sections (knob weight) and fibre content. The solid autotetraploid lines had significantly wider, greener leaves than the diploids, they had significantly fewer but thicker shoots and, although ‘Queensland’ (the diploid parent from which the tetraploids were derived) had a greater total rhizome mass at harvest, its knob size was significantly smaller. From the autotetraploid lines, one line was selected for commercial release as ‘Buderim Gold’. It compared the most favourably with ‘Queensland’ in terms of the aroma/flavour profile and fibre content at early harvest, and had consistently good rhizome yield. More importantly it produced large rhizome sections, resulting in a higher recovery of premium grade confectionery ginger and a more attractive fresh market product.


2015 ◽  
Vol 43 (1) ◽  
pp. 66 ◽  
Author(s):  
Fitri Yulianti ◽  
Agus Purwito ◽  
Ali Husni ◽  
Diny Dinarti

Seedless fruit is one of the criteria (necessary) to improve the quality of Simadu tangerine. The most effective method to obtain seedless triploid cultivars is hybridisation between tetraploid and diploid parents. Simadu tangerine is a diploid plant. Tetraploid Simadu tangerine can be obtained with doubling chromosome using colchicines.The aim of this research was to obtain tetraploid Simadu tangerine shoot which would serve as parent to produced seedless Simadu tangerine. Shoot-tips of Simadu tangerine without leaves were treated with colchicines at four different concentrations (0, 0.1, 0.2, and 0.3%) for 3 hours. The results showed that the high concentration of 0.3% reduced survival rate. The colchicine treatments reduced growth of shoot-tip of Simadu Tangerine.The leaves of colchicines treated shoots were thicker than control. Leaves from control (0% colchicine) and 0.1% colchicine treated shoots had 8.67 and 18.25 chloroplast per pair of guard cells. Compared to those of control, leaves with 0.1% colchicine had lower stomatal density, and larger stomatal size. It appeared that 0.1% colchicine treatment resulted in tetraploid Simadu Tangerine Shoot.<br />Keywords:chloroplasts, doubling chromosomes, stomatal size, stomatal density


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12399
Author(s):  
Wee Hiang Eng ◽  
Wei Seng Ho ◽  
Kwong Hung Ling

Polyploidization has played a crucial role in plant breeding and crop improvement. However, studies on the polyploidization of tropical tree species are still very scarce in this region. This paper described the in vitro induction and identification of polyploid plants of Neolamarckia cadamba by colchicine treatment. N. cadamba belongs to the Rubiaceae family is a natural tetraploid plant with 44 chromosomes (2n = 4x = 44). Nodal segments were treated with colchicine (0.1%, 0.3% and 0.5%) for 24 h and 48 h before transferring to shoot regeneration medium. Flow cytometry (FCM) and chromosome count were employed to determine the ploidy level and chromosome number of the regenerants, respectively. Of 180 colchicine-treated nodal segments, 39, 14 and 22 were tetraploids, mixoploids and octoploids, respectively. The highest percentage of polyploidization (20% octoploids; 6.7% mixoploids) was observed after treated with 0.3% colchicine for 48 h. The DNA content of tetraploid (4C) and octoploid (8C) was 2.59 ± 0.09 pg and 5.35 ± 0.24 pg, respectively. Mixoploid plants are made up of mixed tetraploid and octoploid cells. Chromosome count confirmed that tetraploid cell has 44 chromosomes and colchicine-induced octoploid cell has 88 chromosomes. Both octoploids and mixoploids grew slower than tetraploids under in vitro conditions. Morphological characterizations showed that mixoploid and octoploid leaves had thicker leaf blades, thicker midrib, bigger stomata size, lower stomata density, higher SPAD value and smaller pith layer than tetraploids. This indicates that polyploidization has changed and resulted in traits that are predicted to increase photosynthetic capacity of N. cadamba. These novel polyploid plants could be valuable resources for advanced N. cadamba breeding programs to produce improved clones for planted forest development.


HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 269C-269
Author(s):  
Ping Song ◽  
Wanhee Kang ◽  
Ellen B. Peffley

Regenerating calli of Allium fistulosum × A. cepa interspecific F1 hybrids were treated in vitro with colchicine. A factorial experiment (colchicine concentration × time) was used to recover tetraploids from calli treated with colchicine in vitro. Shoot production of regenerating calli following in vitro colchicine treatment decreased with increasing colchicine concentration and treatment time. Cytological analyses of root tip cells from regenerated plantlets showed that chromosomes of control plantlets (not treated with colchicine) were not doubled. Chromosomes of some plantlets regenerated from in vitro colchicine treated calli were doubled, resulting in tetraploids. Calli treated with 0.1 or 0.2% colchicine in BDS (Dunstan & Short, 1977) liquid medium for 48 or 72 hours yielded the highest number of tetraploid plantlets. These results demonstrate that in vitro colchicine treatment of regenerating calli of interspecific F1 hybrids is effective in recovering tetraploids.


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