Malabadi Ravindra B, Van Staden Johannes
Research Centre for Plant Growth and Development, School of Botany and Zoology, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.
Tree Physiol. 2005 Jan;25(1):11-6. doi: 10.1093/treephys/25.1.11.
Embryogenic cultures were initiated and established from apical shoots of mature trees of three genotypes of Pinus patula Scheide et Deppe. Factors affecting initiation, including cold pretreatment, basal medium composition, growth regulators and gelling agent concentration, and the effect of partial desiccation on somatic embryo maturation were investigated. Cold pretreatment of thick sections (0.5-1.0 mm) of apical shoots at 2 degrees C for 3 days on 0.3% activated charcoal induced white mucilaginous embryogenic callus on initiation medium. Subculture of this embryogenic callus on maintenance medium resulted in the formation of embryonal suspensor masses with proembryos. Partial desiccation (12-90 h) of embryogenic tissue at the proembryo stage of development, prior to transfer to maturation medium containing 9 g l(-1) Gellan gum, enhanced somatic embryo maturation and germinability. The frequency of maturation increased from 5.3 to 16.5% after 12 h of desiccation and from 16.5 to 73.8% after 24 h of desiccation, but longer periods of desiccation were ineffective.
从三种基因型的展叶松成熟树木的顶芽开始并建立了胚性培养物。研究了影响起始培养的因素，包括冷预处理、基本培养基组成、生长调节剂和凝胶剂浓度，以及部分干燥对体细胞胚成熟的影响。将顶芽的厚切片（0.5 - 1.0毫米）在2℃下于0.3%活性炭上冷预处理3天，在起始培养基上诱导出白色粘液状胚性愈伤组织。将这种胚性愈伤组织在维持培养基上继代培养，形成了带有原胚的胚性悬浮细胞团。在转移到含有9 g l(-1)结冷胶的成熟培养基之前，对发育到原胚阶段的胚性组织进行部分干燥（12 - 90小时），可提高体细胞胚的成熟度和发芽能力。干燥12小时后成熟频率从5.3%增加到16.5%，干燥24小时后从16.5%增加到73.8%，但更长时间的干燥无效。
