Occurrence of albino plants in anther and pollen cultures: a problem limiting the application of In vitro androgenesis in crop improvement

摘要

One of the main causes restricting the applications of in vitro androgenesis, especially in cereals, is the regeneration of albino plants. Leaving aside a few exceptions, this phenomenon seems to be restricted to the members of the Poaceae. The problem of low incidence of androgenesis in cereal crops is further aggravated by the presence of high proportion of albinos in the haploid population. Though the exact mechanism still remains to be determined, albinism has been demonstrated to be due to large-scale deletions in the plastid genome interfering with chloroplast development. Some intrinsic factors, such as the genotype of donor plants and the stage of microspore development, and some extrinsic factors, viz. growth conditions of donor plants and cultural conditions, have been shown to influence the incidence of albino pollen plantlets. Such studies are not conclusive enough to warrant generalizations, except perhaps in cases in which the influence of genotype in albino production has been investigated. However, a large volume of fruitful data has accumulated from investigations in the area of androgenesis, contributing to our understanding of the molecular and genetic aspects of chloroplast development and maternal inheritance in higher plants.