Flower morphology and floral sequence in Artemisia annua (Asteraceae)¹

Abstract

Gynomonoecy, early opening of ray florets, and dichogamy of disk florets promote outcrossing in A. annua For breeding and seed development, flowering in genotypes can be synchronized under short days according to the floral developmental stages defined. Floret number and percentage seed fill vary with genotype and may be a beneficial selection criterion.

Selection and Clonal Propagation of High Artemisinin Genotypes of Artemisia annua

“…Artemisinin concentration is an extremely variable trait in A. annua ranging from 0.5 to 1.07% ( Delabays et al, 2001 ). Although the high-heritability of artemisinin content has been experimentally confirmed by broad and narrow-sense heritability ( Ferreira et al, 1995 ; Delabays et al, 2002 ), production of F 1 hybrids produced from homozygous inbred plants has been problematic because A. annua exhibits self-incompatibility ( Peter-Blanc, 1992 ; Wetzstein et al, 2014 ) which results in the inability to produce homozygous lines by inbreeding. The so-called hybrid seed presently available for A. annua is produced by crossing two heterozygous and genetically-different parental genotypes, which results in highly variable progeny.…”

“…Greenhouse stock plants produced from cuttings were used as a source plants for propagation studies. A. annua is a short-day, monocarpic plant with extremely small flowers and seeds ( Wetzstein et al, 2014 ). To prevent flowering under fall and winter day lengths, plants were given supplemental light to maintain a 16-h photoperiod.…”

The Artemisia Genus: A Review on Traditional Uses, Phytochemical Constituents, Pharmacological Properties and Germplasm Conservation

“…In order to opt for successful hybridization in A. annua, its reproductive biology must be well studied and the onset of flowering among the parental must be synchronized for pollen release and stigma receptivity. Therefore, an understanding of floral biology, pollination biology and seed development is necessary for successful breeding in A. annua [88,89]. Recently reported that dried leaves of A. annua (DLA) are effective against Plasmodium sp., in rodent malaria.…”

Germplasm Release of Four High-artemisinin Clones of Artemisia annua L.

“…Artemisia annua seed obtained from China and Brazil and their open pollinated progeny were grown in a greenhouse and field at Purdue to research artemisinin (Ferreira, 1994;Janick, 1994, 1996;Ferreira et al, 1995). In 2007, plants and seed from this material were sent to the University of Georgia for studies of floral anatomy, micropropagation, and selection (Wetzstein et al, 2014(Wetzstein et al, , 2018. Selections were made over successive generations at the University of Georgia from 2007 to 2014, based on agronomic characteristics such as leaf area, shoot biomass, flowering time, and artemisinin concentration.…”