SummaryFruits are an important part of a healthy diet. They provide essential vitamins and minerals, and their consumption is associated with a reduced risk of heart disease and certain cancers. These important plant products can, however, be expensive to purchase, may be of disappointing quality and often have a short shelf life. A major challenge for crop improvement in fleshy fruit species is the enhancement of their health-promoting attributes while improving quality and reducing postharvest waste. To achieve these aims, a sound mechanistic understanding of the processes involved in fruit development and ripening is needed. In recent years, substantial insights have been made into the mechanistic basis of ethylene biosynthesis, perception and signalling and the identity of master regulators of ripening that operate upstream of, or in concert with a regulatory pathway mediated by this plant hormone. The role of other plant hormones in the ripening process has, however, remained elusive, and the links between regulators and downstream processes are still poorly understood. In this review, we focus on tomato as a model for fleshy fruit and provide an overview of the molecular circuits known to be involved in ripening, especially those controlling pigment accumulation and texture changes. We then discuss how this information can be used to understand ripening in other fleshy fruitbearing species. Recent developments in comparative genomics and systems biology approaches are discussed. The potential role of epigenetic changes in generating useful variation is highlighted along with opportunities for enhancing the level of metabolites that have a beneficial effect on human health.

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Protocorm-like bodies (PLBs) of Dendrobium orchids are emerging as a potential source of valuable secondary metabolites. This study examined the effect of four additives namely 1-naphthaleneacetic acid (NAA), kinetin, thidiazuron (TDZ), and activated charcoal (AC) used in culture medium on genetic variability in PLBs of Dendrobium Sabin Blue. Nine ( 9) ISSR primers and eleven (11) DAMD primers were used to assess the genetic variability of PLBs that were subcultured over a period of two years. We confirmed that the use of kinetin in culture medium for two years resulted in the highest rate of somaclonal variation in PLBs. On the other hand, TDZ and activated charcoal registered the lowest genetic variability in PLBs. The findings of this study suggest the importance of selecting additives used in the culture medium to maintain stable genetic lines of PLBs. We recommend that the assessment of somaclonal variations should be performed for long term maintenance of tissue cultures.

Fig, or Ficus carica, is a fruit tree from the Moraceae family and is widely grown in tropical and subtropical regions of the world. Fig plants are mainly propagated through grafting, air layering, and hardwood cutting whereby these methods were found to be less efficient. Plant tissue culture is efficient method to propagate plants, particularly to produce true-to-type platelets for mass multiplication. The aim of this study is to induce multiple shoot formation on Ficus carica cv. Japanese BTM 6 through identifying and optimising the concentrations of 6-Benzylaminopurine (BAP) and Zeatin suited for shoot formation. The axillary shoot tip explants were cultured in MS media supplemented with different concentrations of BAP and Zeatin (0, 0.5, 1.0, 1.5 and 2.0 mg/L) to determine the optimal concentration for the formation of multiple shoots. Number of shoots per explants and the differences in shoot height of explants were calculated after 8 and 12 weeks of culture respectively. Of all the treatments of BAP, MS media containing with 2 mg/L BAP marked the highest number of shoots per explant with the average value of 1.67 ± 0.33 while 1.5 and 2 mg/L of BAP produced the highest differences in shoot height with 0.51 ± 0.08 cm and 0.51 ± 0.07 cm after 12 weeks respectively. Murashige and Skoog (MS) media supplemented with 2 mg/L Zeatin showed the highest production of multiple shoots and differences in shoot height with the average of 0.83 ± 0.219 and 0.32 ± 0.04 cm respectively among all the different treatments of Zeatin. In this study, BAP performed better in shoot induction and elongation as compared to Zeatin for the cultivar Japanese BTM 6.

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