In vitro organogenesis in some citrus species

Abstract

ABSTRACT-In vitro organogenesis of citrus was studied for the genotypes Citrus sinensis cv. 'Natal', C. limonia, C. volkameriana, and C. aurantium, with the use of epicotyl segments-derived explants, cultured in MT salts and vitamins medium supplemented with different concentrations of 6-benzylaminopurine (BAP -0.0; 0.5; 1.0; 1.5, or 2.0 mg L -1 ). For the recalcitrant genotypes C. limonia and C. aurantium the in vitro organogenesis was also studied with internodal segments-derived explants, cultured in MT salts and vitamins medium supplemented with 0; 0.5; 1.0; 2.0, or 4.0 mg L -1 of BAP. The efficiency of culture medium supplementation with the combination of BAP (0.0; 1.0, or 2.0 mg L -1 ) and NAA (1-naphthaleneacetic acid -0.0; 0.3, or 0.5 mg L -1 ) in the development of adventitious shoots was evaluated for C. aurantium. Culture medium supplementation with BAP is not essential for the adventitious shoots development in the four genotypes studied when epicotyl segments-derived explants are used. In general, culture media supplementation with BAP decreased the percentage of responsive explants excepted for C. sinensis cv. 'Natal' and C. limonia when the concentrations of 1.5 and 2.0 mg/L -1 were used. The presence of cytokinin, in concentrations up to 2 mg/L -1 , stimulated the in vitro organogenesis when internodal segments-derived explants were used for C. limonia and C. aurantium. For C. aurantium no adventitious shoots developed in explants (internodal segments) cultured in basal culture medium, without BAP supplementation. Although no statistic differences could be detected, culture media supplementation with the combination of BAP and NAA favored the development of adventitious shoots in C. aurantium. The best concentration of NAA varied according to BAP concentration. The results presented herein show that citrus in vitro organogenesis depends on the interaction of culture medium composition, explant differentiation level, and genotype. Index terms: epicotyl segment, internodal segment, C. sinensis, C. limonia, C. volkameriana, C. aurantium. ORGANOGÊNESE IN VITRO EM ALGUMAS ESPÉCIES DE CITRUSRESUMO-A organogênese in vitro de citrus foi estudada para os genótipos Citrus sinensis cv. 'Natal', C. limonia, C. volkameriana e C. aurantium, utilizando-se de segmentos de epicótilo como explante, cultivados em meio de cultura MT suplementado com diferentes concentrações de 6-benzilaminopurina (BAP -0,0; 0,5; 1,0; 1,5 ou 2,0 mg L -1 ). Para os genótipos recalcitrantes C. limonia e C. aurantium, a organogênese in vitro também foi estudada, utilizando-se de segmento internodal como explante, cultivado em meio de cultura MT suplementado com 0; 0,5; 1,0; 2,0 ou 4,0 mg L -1 de BAP. A eficiência da suplementação do meio de cultura com a combinação de BAP (0,0; 1,0 ou 2,0 mg L -1 ) e NAA (0,0; 0,3 ou 0,5 mg L -1 ) no desenvolvimento de gemas adventícias foi avaliada para C. aurantium. Pode-se verificar que, nos quatro genótipos estudados, a suplementação do meio de cultura com BAP não é essencial para o desenvolviment...

Micropropagation of Citrus indica Tanaka using Shoot tips from Mature Trees

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Efficient protoplast isolation from ovule-derived embryogenic callus inCitrusvolkameriana

“…However, the efficiency of existing protocols may vary depending on the genotype used. Some species and varieties have shown to be recalcitrant to in vitro process in citrus, especially genotypes used as rootstocks (Tavano et al, 2009;Schinor et al, 2011). Although the induction of embryogenic callus lines, especially from ovule tissue, has been extensively investigated in citrus, there are only a few reports on embryogenic callus induction and protoplast isolation in recalcitrant rootstocks such as Volkameriana (Citrus volkameriana L.).…”

Organogênese in vitro e transformação genética de variedades de tangerina (Citrus reticulata Blanco e Citrus clementina hort. ex Tan.)

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