Lab equipment. © INRA, William Beaucardet

Green biotechnologies: paving new paths for agriculture

Brief history of biotechnologies at INRA and elsewhere 

The history of plant biology has been marked by two major milestones: progress made in genomics, which has given rise to technologies such as marker-assisted selection, transgenesis, association genetics... And the discovery of the totipotency of plant cells, which has given rise to many in vitro culture techniques: meristem cultures, embryo cultures, protoplast fusion, double-haploid method, in vitro reproduction, embryo rescue, etc. 

Plant research methods and their applications. © INRA
© INRA

Brief history of in vitro reproduction of plants:

-          1939: Gautheret reports the continuous culture of cambium cells.

-          1952: Morel and Martin are the first to free a plant from virus using meristem cultures of dahlia.

-          1958: Reinert and Stewart obtain the first somatic embryos from carrot cells.

-          1960: Morel reports the first in vitro plant reproduction of orchids.

-          In 1988, more than 450 species can be micro-propagated.

Brief history of artificial mutagenesis

-          Discovery of ionizing radiation at dawn of 20th century.

-          1927: Changes (mutations) caused by radiation are observed to be inherited.

-          Diversification of mutation-inducing agents: physical agents (gama rays, X-rays, ultraviolet rays), chemical agents (EMS, etc.), variations induced by in vitro cell cultures.

-          Use of artificial mutants: 2,252 varieties identified by FAO/IAEA in 2000.

Examples:

  • Grapefruit, aspermia (1970), red colour of pulp (1984)
  • Rice, quality of grain (1970)
  • Sunflower oil rich in oleic acid (1976) (all varieties rich in oleic acid registered in France and USA)
  • Cherry trees, self-fertilising (1985) 
  • Forsythia, compact habit (1985)
  • Carnation, variations in colour
  • Rapeseed rich in oleic acid and rapeseed with reduced linolenic acid content
  • Malt barley, semi-dwarf (more than 150 varieties)

 

Some applications of protoplast fusion

-         Creation of new species:

  • 1978, pomato
  • 2002, Citrus rootstock: Poncirus trifoliata x Citrus reticulata.

-          Introgression of traits by asymmetric fusion:

  • Resistance to leafroll virus introduced in potatoes by S. brevidens
  • Mildew resistance by S. bulbocastanum

-          Manipulation of cytoplasmic traits (cybrids):

  • Creation of genitors for producing hybrid varieties in Brassica, rice and endive

 

Evolution of selection methods and techniques over the past 200 years

-          Selection of homogenous descendants which replaces mass selection (mix of different genotypes practiced since 1850)

-          Hybridisation between strains or species and selection among descendants (1880)

-          Chromosome doubling with colchicine, mutagenesis  (1935)

-          Biometric methods (1950)

-          Cytogenetics: identification of and access to chromosomes (1950)

-          In vitroculture, haploidy, cellular hybridation, plant reproduction, eradication of virus (1950-1980)

-          Identification of molecular markers of traits (1980)

-          Transgenesis (1984)

-          Identification of genes, their sequences and functions (genomics) (since 1990)

-          Selection of mutants with precise modification of target gene (Tilling) (2000)

-          Association genetics (2010)