A shoot regeneration protocol effective on diverse genotypes of sunflower (Helianthus annuus L.)

Abstract

We describe a protocol, and several experiments that helped lead to its development, for sunflower regeneration. Important factors for sunflower regeneration were explant age, cytokinin type and concentration, basal medium, and explant source. We could not induce shoot regeneration from the explants derived from mature tissues including leaf, petiole, and stem. However, use of juvenile explants such as embryo meristem and primordial leaf tissues allowed routine regeneration of 17 different sunflower genotypes. High frequency of shoot regeneration was achieved with these explants taken from seedlings up to 5 d after germination. Explant age was less critical for embryo meristem explants than for primordial leaf tissues. Of the four basal media tested, MS and B5 media produced higher shoot-regeneration frequencies than did Anderson and woody plant media. The highest shoot-regeneration frequency was obtained with MS medium supplemented with 2 mM BA and without auxin. Addition of 1 mM naphthalene-acetic acid to the medium significantly reduced both the percentage of explants producing shoots and average number of shoots per explant. Regenerated shoots were grown to maturity in a greenhouse.

Adventitious shoot regeneration from in vitro stem explants of Phellodendron amurense

“…When we compared the three media, (MS, B5 and WPM), the contents of phosphorus and calcium were similar, while the content of nitrogen was different. The total nitrogen content in WPM medium (14.7 M) was much lower than that in MS (60.03 M) and B5 (27.0 3 M) (Shi et al, 2000). In this study, it appears that the content of total nitrogen might be an important factor that affected shoot regeneration of P. amurense.…”

Establishment of apical shoot meristem culture for in vitro conservation of sunflower (Helianthus annuus L.) genetic resources

“…Fertile plant regeneration (Shin et al, 2000) has been also observed from embryo meristem and primordial leaf tissues. However, the plant heights of their in vitro regenerated genotypes were higher (142-263 cm) than genotypes used in this study (43.33-102.67 cm).…”

“…The process of sunflower regeneration is affected by many factors, either alone or in combination. These include genotype (Dağüstü, 2002;Paterson, 1984;Power, 1987), composition of culture medium (Shin et al, 2000), the age of explant (Dağüstü, 2002;Knittel et al, 1991;Paterson and Everett, 1985;Shin et al, 2000); explant type (Ceriani et al, 1992;Dağüstü, 2002;Shin et al, 2000), and environmental factors (Fiore et al, 1997).…”

Organogênese direta de Orthophytum mucugense

“…Entretanto, para a bromélia Tillandsia eizii, a idade do explante, 21 e 84 dias, não afetou significativamente as variáveis % de explantes com brotos e número de brotos/explante (PICKENS et al 2006). O sucesso na propagação de explantes mais jovens pode ser atribuído à existência de muitas células meristemáticas e indiferenciadas que apresentam crescimento rápido, o que é essencial para iniciar as culturas (SHIN et al, 2000;BISPO et al, 2007). Quanto à variável comprimento médio de brotos, explantes com 40 dias de idade, independente da concentração de regulador aplicada, produziram brotos maiores, 7,80 e 5,99mm, não diferindo significativamente apenas do caule com 20 dias na concentração de 1,30μM de ANA.…”