Global Perspectives and Future Approaches

The genetic resources of the mulberry trees show heterozygous, anemophilic, and hybridization characteristics and are generally prioritized for propagation through trunk and/or buds (Vijayan et al. 2011, 2021). The most appropriate conservation strategy adopted for mulberry genetic resources is the clonal propagation method (micropropagation). In this conservation strategy, existing ex situ conservation methods are applied in the laboratories to genetic resources either in situ or under in vitro conditions (Vijayan et al. 2021). Among the applied methods, ex situ conservation is more frequently preferred (Tikader et al. 2009). There are also research institutes, botanical gardens, national parks, etc., which represent well-protected areas. In these areas the mulberry trees can be preserved in vitro as whole plants (Niino 1995). Although some morphological, anatomical, and physiological characteristics of mulberry trees vary in different habitats and environmental conditions, the first process of conservation is initiated by bringing the collected genetic resources to the germplasm station and subjecting them to systematic characterization, evaluation, and documentation (Tikader et al. 2014). The preservation of mulberry through tissue culture and cryopreservation is also practiced to a certain extent, as it is very suitable in terms of parameters such as minimum space requirement and maintenance costs (Niino 1995; Vijayan et al. 2021). These methods offer several advantages in cryopreservation, such as maintaining mulberry germplasm at an ultralow temperature where cell division and metabolic activities are suspended, thus preserving the materials for long periods with greater genetic stability (Niino 1995; Vijayan et al. 2021). In particular, such a characterization in different mulberry species (M. alba, M. nigra, M. indica, M. cathayana, and M. multicaulis) is done in many countries, notable among these being China and India. The method of freezing genetic resources through cryopreservation is frequently applied in India (Ananda Rao et al. 2007). In fact, various procedures are available to protect valuable mulberry genetic resources, which are necessary for the continuous supply of economically important parts of mulberry species, especially silk, pharmaceutical products, food, cosmetics, and other industrial products (Vijayan et al. 2021).