In vitro organogenesis in watermelon cotyledons

Abstract

-The objective of this work was to study the in vitro organogenesis of Citrullus lanatus, by the induction of adventitious buds in cotyledon segments cultured in medium supplemented with cytokinin. Explants were collected from one, three and five-day-old in vitro germinated seedlings, considering the distal and proximal cotyledon regions. The data obtained showed that in vitro organogenesis of watermelon occurred with higher efficiency, when cotyledon segments from the proximal region collected from three-day-old seedlings were cultivated in medium MS, supplemented with BAP (1 mg L -l ) and coconut water (10%). The histological study showed that the organogenesis occurs directly, without callus formation, on epidermal and subepidermal layers of the explants. Adventitious shoots were characterized by the development of shoot apical meristem and leaf primordia. The formation of protuberances, that do not develop into adventitious buds, was also observed.Index terms: Citrullus lanatus, histological study, adventitious bud. Organogênese in vitro em cotilédones de melanciaResumo -O objetivo do trabalho foi estudar a organogênese in vitro de C. lanatus, pela indução de gemas adventícias, em segmentos de cotilédones, cultivados em meio de cultura suplementado com citocinina. Os explantes consistiram de segmentos das regiões distal e proximal de cotilédones, coletados de plantas germinadas in vitro com um, três e cinco dias de idade. Os dados obtidos mostram que a organogênese de melancia, in vitro, ocorre com maior eficiência em segmentos da região proximal dos cotilédones, coletados de plântulas com três dias de idade e cultivados em meio de cultura MS, suplementado com a combinação BAP (1 mg L -l ) e água de coco (10%). Pelo estudo histológico, verificou-se que a organogênese ocorre diretamente, sem a formação de calo, na epiderme e subepiderme do explante. As gemas adventícias foram caracterizadas pela presença de meristema apical e primórdios foliares. Observou-se, também, o desenvolvimento de protuberâncias que não se desenvolvem em gemas adventícias.Termos de indexação: Citrullus lanatus, estudo histológico, gema adventícia.

Direct shoot regeneration via organogenesis in chieh-qua (Benincasa hispida Cogn. var. Chieh-qua How)

“…Apparently, the effect of alternating darkness and light during seed germination on shoot regeneration from cotyledon varied in different species. Previous studies have shown that the frequency of shoot regeneration was influenced by the seedling age in cucurbits (Compton, 2000;Lee et al, 2003;Krug et al, 2005;Ntui et al, 2009). In the present study, the shoot regeneration frequency of cotyledons from 4-day-old seedlings was higher than those from 5 and 6-day-old seedlings.…”

“…Many studies have demonstrated in vitro that low-salt, ½ and ¼ MS media promote shoot rooting in cucurbits (Lee et al, 2003;Han et al, 2004;Thomas and Sreejesh, 2004). Auxin is also widely used for root induction in cucurbits, including IAA (Han et al, 2004), NAA (Kathiravan et al, 2006;Kim et al, 2010) and IBA (Sarowar et al, 2003;Krug et al, 2005). All these observations revealed that the shoot rooting response may be affected by the growth medium composition.…”

Morpho-histological study on shoot bud regeneration in cotyledon cultures of pepper (Capsicum annuum)

“…Thus, the scare plant regeneration seems to be a consequence of infrequent differentiation of normal apical shoot meristems and not due to a defect in shoot development from available meristems as observed in earlier scanning electron microscopy studies on Capsicum (Wolf et al 2001). Interestingly, the development of adventitious 'blind leaves' has been reported in cotyledon explants of pepper (Wolf et al 2001) and in the members of Cucurbitaceae (Gaba et al 1999;Stipp et al 2001;Krug et al 2005).…”

“…Complementary anatomical analysis confirmed the atypical bud organization of the Brought to you by | MIT Libraries Authenticated Download Date | 5/11/18 5:35 PM majority of these structures as reported by Delis et al (2005). They may only be considered as leaf-like structures because their tissue is likely parenchymatous (Krug et al 2005). Few others are shoots or shoot-like structures because they have a classical meristem organization (Haensch 2004;Salaj et al 2005).…”

Micropropagation of an elite F1 watermelon (Citrullus lanatus) hybrid from the shoot tip of field grown plants

“…The shoots and were more prone to rooting by increasing the subcultures. IBA is one of the most commonly used plant growth regulator for root induction in watermelon (Krug et al 2005) and other cucurbits, including summer squash (Pal et al 2007), ash gourd (Thomas and Sreejesh, 2004) and interspecific hybrid of Cucurbita (Sarowar et al 2003). In vitro-rooted plantlets were transferred to soil pot for acclimatization (Fig.…”