Enhancing the percentage of success of semi-micrografting to propagate Citrus spp. free of Tristeza virus and Fusarium oxysporum-related diseases

Lime ( Citrus aurantifolia ) is the primary vitamin-C source in our diet. It is rich in antioxidants and anti-inflammatory properties, which are vital to disease prevention. Widely grown worldwide, lime is valued for its medicinal and economic benefits. Grafting is the most used method for propagating citrus, as seed propagation results in diverse cultivars. However, one drawback of grafting is the potential transmission of diseases. To address this, an in-vitro micrografting technique was developed to prevent disease transmission during plant propagation. However, this technique requires modification due to its high cost, demand for skilled labour, and long propagation time. This study introduced a cost-effective, labour-efficient, and timesaving modified semi-micrografting technique. Various treatments were evaluated based on graft success percentage, and the results were analysed using one-way analysis of variance and least significant difference tests. The results revealed that the combination of \(10 \text{m}\text{g}{\text{L}}^{-1} \text{g}\text{i}\text{b}\text{b}\text{e}\text{r}\text{a}\text{l}\text{i}\text{c} \text{a}\text{c}\text{i}\text{d}\), \(10 \text{m}\text{g}{\text{L}}^{-1} \text{2,4}-\text{d}\text{i}\text{c}\text{h}\text{l}\text{o}\text{r}\text{o}\text{p}\text{h}\text{e}\text{n}\text{o}\text{x}\text{y}\text{a}\text{c}\text{e}\text{t}\text{i}\text{c} \text{a}\text{c}\text{i}\text{d}\), \(500 \text{m}\text{g}{\text{L}}^{-1} \text{a}\text{s}\text{c}\text{o}\text{r}\text{b}\text{i}\text{c} \text{a}\text{c}\text{i}\text{d}\), 50 mM calcium chloride and 30 µL of Ceylon cinnamon leaf oil was the best treatment, as it had the highest grafting success rate (62.22 ± 5.091%) compared to the other treatments. The present study proved that combining 2,4-dichlorophenoxyacetic acid, gibberellic acid, ascorbic acid, calcium chloride, and Ceylon cinnamon leaf oils improved the semi-micrografting technique and success of grafting. Grafted plants were tested using polymerase chain reaction and found free of Citrus tristeza virus and Fusarium oxysporum- related diseases. The present modified semi-micrografting technique has demonstrated that disease-free citrus plants can be produced with a relatively high success rate and at a low-cost.