Cytogenetic characterization of induced autotetraploids in grass pea (Lathyrus sativusL.)

Abstract

-Induction of polyploidy was successfully achieved in grass pea (Lathyrus sativus L.) variety BioR-231 using 0.10% (eight hours three days), 0.20% (six hours two days and eight hours two days), 0.30% (eight hours one day) and 0.40% (six hours one day) colchicine solution by apical shoot tip treatment of young seedlings. Compared to diploid variety the tetraploid plants were morphologically distinguished by luxuriant vegetative growth showing broader and thicker leafl ets and stipules, fl attened stems, increased number of branches, enhanced length of tendril as well as peduncle, delayed fl owering and reduced pollen fertility. Number of stomata decreased but its size increased signifi cantly in tetraploids. Presence of 7II and 7-7 separation at meiosis-I were the usual feature in diploids (2n=2x=14) while occurrences of 28 chromosomes in different combinations of multivalents, bivalents and univalents at metaphase-I and unequal separation of chromosomes toward the spindle poles, bridge formation, laggard at anaphase-I distinguished tetraploid (2n=4x=28) from diploid plants, cytogenetically. All these meiotic irregularities through the formation of unbalanced gametes have been ascribed for pollen sterility and reduced seed yield in tetraploid plants. Nature of origin, morphology and formation of trivalent as well as quadrivalent indicated autopolyploid nature of present tetraploids in grass pea. Occurrence of majority pairing as bivalents has also been discussed.

Production of Autopolyploid Lowland Switchgrass Lines Through In Vitro Chromosome Doubling

“…For switchgrass, treatment duration, rather than chemical concentration, is the major factor that must be optimized in order to achieve the highest efficiency of chromosome doubling. Similar results have been reported in other plant species, such as Miscanthus [19] [24] and grass pea [29].…”

“…Chromosome doubling can be induced by treating the plant tissue with heat or cold shock [26,27], or by treating with antimitotic agents like NO gas [28], colchicine [24,29], oryzalin [24,30], and trifluralin [31]. Because antimitotic chemical treatment is relatively easy to perform and the results are reproducible, it is the most frequently used method for inducing chromosome doubling in many plant species [24,32].…”

Production of Trifolium pratense L. and T. hybridum L. tetraploid populations and assessment of their agrobiological characteristics

“…It is difficult to compare our results with those obtained by other researchers since different concentrations of mitosis inhibitors, exposure times and plant species were used (Hansen, Andersen, 1998;Barufaldi et al, 2001;Talukdar, 2010;Wu et al, 2010). Numerous research publications have indicated that colchicine is the most common mitosis inhibitor used for the production of polyploids of legumes (Anderson et al, 1991;Algan, Buyukkartal, 2000;Wang et al, 2009;Wu et al, 2010;Chaisan et al, 2013).…”

“…The success of polyploidy induction depends on several variables: plant species, antimitotic agents, explant types, exposure times and concentrations (Dhooghe et al, 2011). Traditionally, colchicine treatment is performed on germinating seeds (Wu et al, 2010) and 7-day old seedlings (Abd El-Naby et al, 2012), apical meristems (Schifino, Morales Fernandes, 1987), apical buds (Wang et al, 2009;Talukdar, 2010), axilary meritems (Anderson et al, 1991), epicotyls (Bliznyuk, Filipovich, 2007) and cotyledons (Stanys et al, 2006).…”

“…The 0.2% colchicine solution proved to be optimal (Wu et al, 2010). Treatment of Lathyrus apical buds with 0.3% colchicine (Talukdar, 2010). Three colchicine treatment methods were used to produce Cyamopsis tetragonoloba L. polyploids: seed treatment, cotton swab method and method of immersion of cotyledonary leaves.…”