Evaluation of explants for in vitro propagation of Citrus indica Tanaka - An Endangered Species

Abstract

<jats:p>Of the five explants viz., shoot tip, nodal segment, leaf disc, cotyledon and root tip excised from exegenic seedlings of Citrus indica Tanaka shoot tip cultured in MS supplemented with 0.5 mg/l of BAP generated shoots within 4.74 days, exhibiting highest percentage of response (85.82%) with highest number of shoots (8.9) and shoot length (3.04 cm). On the other hand nodal segment cultured in MS supplemented with 1.0 mg/l BAP showed 80% response in 5.16 days with a shoot number of 5.41 and shoot length of 2.43 cm. Cotyledon explants inoculated on MS supplemented with1.0 mg/l of TDZ produced shoots in 20 days with the highest response of 69.88%, with 3.77 shoots per cotyledon and shoot length of 2.03cm. Viable callus was obtained from leaf disc cultured on half strength MS medium with less Ca++ with 2, 4-D 0.5 mg/l + Kn 0.25 mg/l. This callus when inoculated on half strength MS medium with Kn 1.5 mg/l showed highest shoot bud proliferation of 66.66% with 10.06 shoots per callus. Root tip explant failed to produce any shoots. In vitro raised shoots of Citrus indica when cultured on half strength MS medium supplemented with NAA (1.0 mg/l) showed 80 % rooting in 5.66 days, with highest number of roots (6.16 per shoot) and longest root (3.78cm). Ninety per cent of in vitro rooted plantlets of Citrus indica survived in open conditions.&#x0D; Plant Tissue Cult. &amp; Biotech. 30(1): 87-96, 2020 (June)</jats:p>

Micropropagation of Citrus indica Tanaka using Shoot tips from Mature Trees

“…Early root initiation and higher number of roots were achieved when 1 mg/l NAA was used in MS media. Similar observation was also reported by Sangma et al (2020), in Citrus indica. The combination of cytokinins did not show any significant improvement in root initiation.…”

“…The best treatments for achieving early shoot initiation, highest number of shoots per explant and longest shoots was found to be 0.5 mg/l BAP and 0.5 mg/l BAP + 1.0 mg/l Kn. Efficacy of 0.5 mg/l BAP was also reported by Sangma et al (2020) in a similar work carried out on micropropagation of Citrus indica. Although both the studies exhibited similar trend, the number of days required for shoot initiation and the mean number of shoots per explants varied significantly.…”

“…In a study conducted by Sangma et al (2020) shoot tip collected from in vitro germinated seedlings proved to be the best explant for in vitro multiplication of C. indica. However, in that method availability of sufficient explants for mass multiplication greatly depended on availability of sufficient seeds, which is very limited.…”

In vitro plant regeneration of Artocarpus heterophyllus Lam. using shoot tips of mature trees

“…with the ndings made byHamed et al (2007) in Jackfruit, who found the best results in MS medium out of B5 and WPM. The positive effect of full-strength MS medium over other media for axillary shoot proliferation was also studied previously in the Moraceae family, such as Ficus carica(Kumar et al,1998), Morus indica(Niratker et al, 2015) and Artocarpus lakoocha(Verma et al 2015), as well as in some other woody trees such as Lagerstromia parvi ora(Tiwari et al, 2002), Pterocarpus marsupium(Husain et al, 2008), Colutea istria (Hegazi and Gabr, 2010) and Citrus indica(Sangma et al, 2020).…”

Propagation of “Valencia” orange (Citrus x sinensis Osbeck) by minigraft

“…is based on T-budding 40-50 cm rootstocks with scion buds of specific cultivars, in an 18-24 months process to obtain plant material ready to plant in field crops, after mother plants have been carefully selected (Kamanga et al, 2017). Attempts to speed up the process include the use of tissue culture techniques such as rootstock production through micropropagation (Vashisth et al, 2020) and in vitro micrografting; however, low multiplication rates and time for ex vitro plantlet recovery are still a challenge (Chamandoosti, 2020;Sangma et al, 2020). The success of grafting is founded on a vascular reconnection between rootstock and scions, a process that involves hormones, molecular factors, and even whole genome transfer at the grafting area (Rasool et al, 2020;Gautier et al, 2019).…”