Plant Diversity ›› 2015, Vol. 37 ›› Issue (06): 767-778.DOI: 10.7677/ynzwyj201515091

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Encapsulation-Dehydration and Encapsulation-VitrificationBased Cryopreservation of in vitro-Grown Shoot-Tips of Medicinal Plant Astragalus membranaceus

 YIN  Ming-Hua, HONG  Sen-Rong   

  1. College of Life Sciences, Shangrao Normal University, Shangrao, Jiangxi 334001, China
  • Received:2015-05-26 Online:2015-11-25 Published:2015-09-23
  • Supported by:

    The National Natural Science Fund in China (31360072)

Abstract:

 Shoot tips of Amembranaceus excised from in vitrogrown axillary bud were encapsulated in calciumalginate beads. Subsequently, shoot tips were precultured in liquid MS medium enriched with 075mol·L-1 sucrose for 5d at 25℃ and then desiccated aseptically on dried silica gel for 5h to a water content of 231% (fresh weight basis) prior to immersion in liquid nitrogen (LN) for 1d. After rewarming at a 40℃ water bath for 2-3min and transferred to solid culture medium for shoot tip recovery. About 50% of cryopreserved shoottips grew into shoots within 2 weeks after plating. Cryopreservation of Astragalus membranaceus (Fisch.) Bge. shoot tips by encapsulationvitrification has also been developed. Excised shoot tips were firstly encapsulated into alginategel beads and then precultured in liquid MS medium containing 1mg·L-1 6BA, 005mg·L-1 NAA and 075mol·L-1 sucrose at 25℃ for 3d. After loading for 90min with a mixture of 2mol·L-1 glycerol and 04mol·L-1 sucrose at 25℃, shoot tips were dehydrated with PVS2 for 120min at 0℃ prior to direct immersion in liquid nitrogen for 1d. After rapidly thawing at a 37℃ water bath for 2-3min, shoot tips were washed for 10min with liquid MS medium supplemented with 1mg·L-1 6BA, 005mg·L-1 NAA and 12mol·L-1 sucrose at 25℃ and then postcultured on solid MS medium supplemented with 2mg·L-1 6BA, 005mg·L-1 NAA. The regeneration rate of shoot tips amounted to nearly 80%. Both of plantlets regenerated from cryopreserved shoot tips were morphologically uniform, which both showed as that of control plants. Thus, this encapsulationdehydration and encapsulationvitrification technique appears promising as a routine method for the cryopreservation of shoottips of Amembranaceus.

Key words: Cryopreservation, Encapsulation-dehydration, Encapsulation-vitrification, Astragalus membranaceus (Fisch.) Bge., Shoot tips, Germplasm conservation

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