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plants from them enlhuscd scientists for adding new genetic elements and earliest reports
were of Hess (1969; 1970) when no tools for transfer and characterization of transformed
plants were available. Discovery of ability of the soil n~icroorgan~sm Agroboc!erhoii
iu~iieJucie~ls to trensfer its T-DNA to the pinlit genollie revolutio~~ized tliis arca and crcated
altogether a differcnt faculty of science.
2.1.1 Various lnetl~ods of gel~etic tr:r~~sfo~.~~~atiol~ in plnnts
Various neth hods of gene Iralisler ~nlo pl:ints have been designed w~tll
Agrobacierii~nl-mediated transfer as the principal ~netliod. Its miraculous ability to transfer
part of its ge~ietic material, T-DNA into the plan1 genonle for its own beliefit was one of
the significa~lt discoveries of 20Ih century. V;ist literature accumulated in describing tl~e
whole mcclianisnl and ~PP;II.:I~IIS used by ilic microbe Tor gene transfer. llence, this nietl~od
will be dealt in detail in tile foilow~~~g sccrloll. Metliods oliier tl1a11 those relying 011 the
Agrohiicie~~ii~~ii sucli ;IS b~olis~ics, n~icroi~ijcct~vii elc. ir~ll bc dsacribcd ill 1111s aection.
"li~oiisuc" IS n short term for b~ological b;lIlistics; the proccss is one by whicli
biological r~iolccule>, sucli as DNA and RNA, are accclcrated (usually on microcarriers,
termed microprojcctiles) by gullpowder, con~prcsscd gas or other means. The biological
molecules are driven nt liigh velocity inlo the torgct, i~i this contcxt, tile plant cells. A team
of nanoiibr~car~on fac~lity of Col-11el1 Uii~vers~ty developed this tccl~nique, and Sanford
(1988) gave early descriptio~~s. Tlils 1s b;~sically si~nplc device wllere the genetic lrlaterial
is coated on to the tungstei~ or gold pal-ticlcs illid accelerated with 11igI1 pressures into the
plant cells. Dur~ng subsciluent years, tliis device tcok serles of cha~~ges to fit cornmerc~al