Mulberry biodiversity conservation through cryopreservation

Abstract

A 238 mulberry germplasm accession collection from diverse regions maintained under tropical conditions was identified from an ex situ field gene bank. The purpose was to prioritize the in vitro conservation and cryopreservation to develop long-term biodiversity conservation for ensuring sustainable utilization of these valuable resources. Reliable cryo techniques using desiccation and slow freezing of winter-dormant buds were used. Storage potential of bud grafts of different Morus species at −1.5°C for 90 d indicated species-specific variation, and most of the wild species were found sensitive. In vitro regeneration and cryopreservation (−196°C) protocols using differentiated bud meristems, like axillary winter-dormant buds, were worked out for a wide range of landraces, wild, and cultivated varieties of Morus. Buds maintained under subtropical location are also amenable for cryopreservation. Successful cryopreservation of winter-dormant buds belonging to Morus indica, Morus alba, Morus latifolia, Morus cathayana, Morus laevigata, Morus nigra, Morus australis, Morus bombycis, Morus sinensis, Morus multicaulis, and Morus rotundiloba was achieved. Among wild species, Morus tiliaefolia and Morus serrata showed moderate recovery after cryopreservation. Survival rates did not alter after 3 yr of cryopreservation. Inter-simple sequence repeat markers were used to ascertain the genetic stability of cryopreserved mulberry germplasm accessions, which showed no difference detected among the plantlets regenerated from frozen apices in comparison to the nonfrozen material.

Cryopreservation of white mulberry (Morus alba L.) by encapsulation-dehydration and vitrification

“…Cryopreservation of Morus alba L. was previously reported using winter-dormant buds by Atmakuri et al (2009). Dormant buds successful cryopreservation is related to the cold-hardy state of explants and consequently to the temperature fluctuation of the year (Towill and Ellis 2008).…”

“…biodiversity is a priority and large ex situ in field germplasm collections are present in China, Japan and India (Atmakuri et al 2009;Sohn 2003). Cryopreservation of Morus spp.…”

“…Cryopreservation of Morus spp. have been developed using winter-dormant buds (Atmakuri et al 2009;Niino et al 1992b) and in vitro-grown shoot apices or buds in Morus bombicys (Niino 1995;Niino et al 1992a;Niino and Sakai 1992;Yakuwa and Oka 1988).…”

Pomological and quality traits of mulberry (Morus spp.) germplasm from Gorno Badakhshan in the Western Pamir

“…The high tolerance to saline soils allows this species to play an important ecological role and its range in the world is currently reported between 50°N and 30°S latitude (El Obeidi, 2005). Although the preservation of the gene pool of the mulberry has been made mainly for sericulture (Atmakuri et al, 2009), as the plants are mainly used for the leaves, the valorization of the Morus spp. is essential for the development of the human activities and the subsistence in the poorest areas.…”

“…is essential for the development of the human activities and the subsistence in the poorest areas. More recently, red and black mulberry fruits are highly consumed in different countries because of their high nutritional compounds and they have gained an important position in the food industry due to the presence of anthocyanins (Ozgen et al, 2009), and other biologically active substances such as antioxidants, antimutagens and anticarcinogens (Atmakuri et al, 2009). In Tajikistan mulberry fruits are processed to obtain special traditional products such as "tut", "pikht", "bekmez" and "dosti" (respectively sun dried mulberries, ground dried mulberries, mulberry syrup and mulberry spirit), offering a good help in food consumption; however the biochemical and nutritional composition of neglected, used and commercialized cultivars is poorly known (Giuliani et al, 2011).…”