Effects of Growth Regulators on In Vitro Plant Regeneration in Durum Wheat

Abstract

Work on improvement of durum wheat (Triticum turgidum L.) using tools of biotechnology is limited. Development of a reliable in vitro plant regeneration procedure for this important cereal is a prerequisite for its improvement by genetic transformation. Here, we report the effects of three growth regulators (GRs), 2,4‐D (2,4‐dichlorophenoxyacetic acid), picloram (4‐amino‐3,5,6‐trichloropicolinic acid), and dicamba (3,6‐dichloro‐o‐anisic acid), on callus induction and plant regeneration from scutellum cultures of four commercial durum cultivars: Ben, Maier, Munich, and Lebsock. Callus induction was obtained from isolated scutella cultured on modified Murashige and Skoog (MS) basal medium. After 4 wk of callus induction, all calli were plated on MS basal medium for regeneration. The regenerated plantlets were fertile, maintained the normal chromosome number (2n = 4x = 28) and structure as revealed by fluorescent genomic in situ hybridization (fl‐GISH), and showed no apparent somaclonal variation. Genotype and callus induction medium played a dominant role in plantlet regeneration. Dicamba proved the best GR for inducing compact callus and also gave the highest proportion (0.16) of regenerated plants across the four cultivars. Overall, Maier gave the highest proportion (0.27) of plantlet regeneration when dicamba at 2.0 mg L−1 concentration was used for initial callus induction. These results will facilitate genetic transformation work with durum wheat.

Callus induction and plant regeneration by Brazilian new elite wheat genotypes

“…Some authors reported a better response of Picloram compared to 2,4-D for induction and long-term maintenance of regenerative callus from immature embryo explants in barley (Kachhwaha et al1997), a species related to wheat, and durum wheat (Satyavathi et al 2004). Barro et al (1999) reported that in wheat the addition of Picloram (2 mg L -1 ) together with 2,4-D in culture medium increased plantlet regeneration by 50%.…”

Efficient In Vitro Somatic Embryogenesis and Plant Regeneration from Mature and Immature Embryos of Wheat ( Triticum aestivum L.)

“…2,4-D was used successfully for callus induction in numerous experiments but this type of auxin at higher concentrations increases chromosomal instability and cause to somaclonal variation [31]. Therefore, in subsequent studies dicamba and picloram were used instead of 2,4-D [32]. In this study, two different synthetic auxins (2,4-D and picloram) in combination and alone were used for callus induction and somatic embryogenesis.…”

The effect of genotype on a barley scutella culture. Histological aspects

“…Efficient regeneration is usually observed on calli that originated from embryos or their parts [7,[11][12][13][14][15][16]. Histological studies have identified the scutellum of an immature embryo as the tissue from which embryogenic calli originate [17][18][19][20].…”