▎ 摘　　要

NOVELTY - In vitro culturing of early pear stem tips comprises e.g. ultrasonically cleaning workbench, cutting the early pear stem tip to size of 0.2-0.3mm, inoculating into the medium one comprised of Murashige and Skoog medium + 0.3-0.5 g/l graphene quantum dot + 30 g/l sucrose + 0 g/l agar, after inoculation, placing material in a culture chamber for routine conditions and dark culture, culturing on medium one for 7-10 days, transferring the tip of the early pear into the medium two comprised of Murashige and Skoog medium +1-2 mg/l thiabendazole + 0.1-0.3 mg/l 1-naphthaleneacetic acid + 0.3-0.5 g/l graphene quantum dot + 30 g/l sucrose+ 7.5 g/l agar, after inoculation, placing the material in a culture chamber for routine conditioning and culturing on medium 2 for 60-90 days, transferring the early pear single bud into the medium three: Murashige and Skoog medium + 1-2 mg/l thiablon + 0.1-0.3 mg/l 1-naphthaleneacetic acid + 0.3-0.5 g/l graphene quantum dots + 30 g/l sucrose + 7.5 g/l agar. USE - The method is useful for in vitro culturing of early pear stem tips. ADVANTAGE - The method has early stem tip browning, high survival rate, provides strong growth and has easy transplanting. DETAILED DESCRIPTION - In vitro culturing of early pear stem tips comprises (1) ultrasonically cleaning workbench, cutting the early pear stem tip to size of 0.2-0.3mm, inoculating into the medium one, adding Murashige and Skoog medium + 0.3-0.5 g/l graphene quantum dot + 30 g/l sucrose + 0 g/l agar, after inoculation, placing material in a culture chamber for routine conditions and dark culture, (2) culturing on medium one for 7-10 days, transferring the tip of the early pear into the medium two comprised of Murashige and Skoog medium +1-2 mg/l thiabendazole + 0.1-0.3 mg/l 1-naphthaleneacetic acid + 0.3-0.5 g/l graphene quantum dot + 30 g/l sucrose+ 7.5 g/l agar, after inoculation, placing the material in a culture chamber for routine conditioning and (3) culturing on medium 2 for 60-90 days, transferring the early pear single bud into the medium three: Murashige and Skoog medium + 1-2 mg/l thiablon + 0.1-0.3 mg/l 1-naphthaleneacetic acid + 0.3-0.5 g/l graphene quantum dots + 30 g/l sucrose + 7.5 g/l agar, after inoculation, placing material in a culture chamber for routine conditional culture, (4) after 60-90 days of culture on medium 3, transferring the early pear adventitious bud into the medium four comprised of 1/2 Murashige and Skoog medium + 0.5-1 mg/l 1-naphthaleneacetic acid + 0.3-0.5 g/l graphene quantum dot + 30 g/l sucrose + 7.5 g/l agar, after inoculation, placing the material in a culture chamber for routine conditioning, (5) culturing on medium four for 60-90 days, early pears cannot be rooted to form a complete robust test tube seedling.