Departments of Biotechnology Research and Data Management, Plant Breeding Division, Pioneer Hi-Bred International, Inc., 51031, Johnston, IA, USA.
Theor Appl Genet. 1985 Aug;70(5):505-9. doi: 10.1007/BF00305983.
Embryogenic callus consisting of both Type 1, firm, compact, translucent, relatively slow growing callus and Type 2, highly friable, rapidly growing callus with well-formed somatic embryos, were observed in elite maize germplasm, notably B73 and hybrids with B73. Parental genotype is very important in the ability to identify and isolate embryogenic callus after 14 and 28 days in culture. A partial diallel analysis revealed that a large proportion of the genotypic variation was of the additive type although heterosis did positively increase culture response in most cases. A significant negative maternal effect for culture response was noted for inbred B73 from Reid-type germplasm while four lines sampled from Lancaster germplasm showed similar response whether used as male or female. Although significant media differences were observed in some genotypes, culture media did not preclude observation of Type 1 or Type 2 embryogenic cultures in this study after 14 and 28 days. Plants could be regenerated from all genotypes in this study after 14-days of culture, but not all genotypes were capable of sustained subculture and plant regeneration. Plant regeneration from Type 2 cultures of B73 and B73 hybrids has been obtained up to a year after initiation.
在优良的玉米种质中，观察到了胚性愈伤组织，包括 1 型，紧实、致密、半透明、生长缓慢的愈伤组织和 2 型，高度易碎、生长迅速、具有良好体细胞胚的愈伤组织。在培养 14 和 28 天后，胚性愈伤组织的鉴定和分离能力与亲本基因型密切相关。部分双列分析表明，尽管杂种优势在大多数情况下确实会增加培养反应，但大部分基因型变异属于加性类型。从 Reid 型种质中获得的自交系 B73 存在显著的母体负效应，而从 Lancaster 种质中选取的四条品系无论作为雄性还是雌性使用，其培养反应都相似。尽管在某些基因型中观察到显著的培养基差异，但在本研究中，在培养 14 和 28 天后，仍然可以观察到 1 型或 2 型胚性培养物。在本研究中，所有基因型在培养 14 天后都可以再生植株，但并非所有基因型都能够进行持续的继代培养和植株再生。在启动后一年，已经从 B73 和 B73 杂种的 2 型培养物中获得了植株再生。
