In this review, I revisit the concept of androgenesis from such an integrative perspective, focusing on these different experimental (or spontaneous) biological pathways to obtain a haploid (or potentially DH) individual from the male gametophyte or its precursors, and exploring the cellular and/or molecular triggers that may potentially induce each of them.
The term androgenesis was initially confined to a male-specific form of parthenogenesis by which an embryo is believed to originate from a fertilized egg where the female nucleus is somehow inactivated or eliminated (Fig.
In maize (Zea mays), the highest mean frequency of spontaneous androgenesis reported is 1/80,000 in a sample size of 400,000 individuals from ordinary strains (Chase, 1969; Goodsell, 1961).
According to Kermicle experiments (Kermicle, 1969, 1971, 1994), spontaneous androgenesis in maize seems to be under genetic control.
Some of these factors, which may also be present in other types of haploid-inducing techniques (gynogenesis through interspecific or intergeneric hybridization) are not present in most of the reported cases of in vivo androgenesis.
Doubled haploid sunflower (Helianthus annuus) plant production by androgenesis
: fact or artifact.
Response of anther explant to androgenesis
process was controlled by genetical and nongenetical factors that influenced by agents such as genotype[3,4,6,8,10,17], development stage of pollen grain[2,3,6,8,9,1318,19], chemical, cold and heat pretreatments [3,17], mother plant condition (from a nutrition, pests, diseases and irrigation point of view), season of explant choice (growth temperature of mother plant), medium composition[3,4,8,17], rate of growth regulators [3,4] and dark-light regimes [3,5,6].
Furthermore, plastids of the microspore/pollen grains interfere with the success of androgenesis, especially in Poaceae.
This has a direct effect on the yield of androgenesis, especially the rate of albino regenerated plantlets.
Androgenesis consists of regenerating in vitro haploid plantlets from unicellular microspores that are initially programmed to develop into a pollen grain.
STARCH GRAINS AND MICROSPORE COMPETENCE IN ANDROGENESIS
The uninucleate microspore stage is uniformly recognized as the most suitable stage of pollen development for initiating androgenesis with greatest chances of success.