Molecular Plant Breeding 2016, Vol.7, No.13, 1-11
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2 Coleoptile &Inflorescenses (Benkirane et al., 2000).
3 Seeds (Cure and Mot, 1978; Gosch-Wackerle et al., 1979).
4 Shoot apical meristems (Ahmad et al., 2002).
5 Anthers (Armstrong et al., 1988).
Tissues responds were different during plantlet regeneration on in-vitro conditions (Delporet et al., 2001).
Embryos were used for callus culture or DNA delivery techniques in case of wheat plants (Chawla, 2002). Some
types of ex-plants showed a vital role in regeneration process used in culture. Regeneration of wheat plant through
peduncle was double than regeneration from Rachis plant (Majewska et al., 2007). Most prominent technique to
overcome many practical problems is in-vitro culturing of embryo (Dunwell, 1986). Five spring and five winter
wheat genotypes were studied by Kim et al., (2011) to develop appropriate regeneration protocol. The more
effective genotypes in plantlet formation were spring wheat genotypes as compared with winter wheat genotypes.
Optimum developmental stage and embryo length were at 13-14 days and 1.0-1.5 mm respectively to evaluate the
regeneration efficiency. Embryos selection with high frequencies of embryogenesis and regeneration capabilities
could be more helpful for efficient genetic improvement of wheat plant.
3 Embryo Culture
Embryo culture, an in-vitro technique, is referred as embryo rescue technique used to save deterioration of hybrids.
The first mature embryo culture was proposed in 1904 by Norstong. Mature embryos of crucifer were used on a
salt medium mixed with sugar. Interspecific hybridization is the specific technique for embryo culture used in
plant breeding due to abortion of most of the embryo crosses. Failure of endosperm development is known as the
main cause of this abortion (Hu and Wag, 1986) In vitro embryo culture can solve many practical breeding
problems to facilitate plant breeders (Dunwell, 1986). Embryo culture may help in the study of nutrition,
metabolism and developmental stages of plant. Embryo culture technique can evaluate the effect of plant hormone,
growth requirement and environmental conditions on embryo regeneration and embryogenesis (Yeung et al.,
1981). This technique can localize the site for germination. In cryopreservation, embryogenesis, germination
promoters and technique inhibitors act as a localized site (Grout, 1986). Embryo culture can determine the seed
viability and is very useful in assessing the non-ripened and ripened seeds in peach (Tukey, 1944).
4 Mature Embryo Culture in Wheat
Embryos with or without endosperm can be helpful to obtain regeneration of plantlets and induction of embryos
(Ozias-Akins and Vasils, 1983 and Zale et al., 2004). Endosperms of mature embryos can also be used for
regeneration of plantlets and callus formation (Delporte et al., 2001 and Filippoy et al., 2006). Hanning (1904)
obtained viable plant from mature embryos. Experiment was conducted on mineral salt containing medium under
aseptic conditions (Norstog, 1979). Genotype response towards regeneration and induction of callus were checked
to culture mature embryos (Fazeli-Nasab et al., 2012). By Mature embryo cultures considerable differences in
wheat cultivars were found in form of regeneration of plants and effectiveness of callus (Zale et al., 2004). Mature
embryos with or without endosperm were used to callus formation and plant regeneration in wheat (Jun-Ying et al.,
2006). Embryogenic callus percentage was found more in embryos which are endosperm free (Turhan and Baser,
2004). Mature embryos culture in Triticum aestivum and Triticum durum lead to the development of transgenic
plants at a rate 1.28 % to 1.77 % of transformation (Patnaik et al., 2006). It can be used as valuable substitute for
immature embryos due to easy access and isolation of mature embryos, (Ding et al., 2009). Mature embryos
express lesser variability at their physiological state (Yu et al., 2008).
5 Immature Embryo Culture in Wheat
Callus formation, immature embryo and regeneration of shoot among all explants can produce excellent results
(Hou et al., 1997; Arzani and Mirodjagh, 1999; Sarker and Biswas, 2002). Transformation and regeneration in
Agro bacterium can be inducted by previously cultured embryos callus and immature wheat embryos (Cheng et al.,
1997). Immature embryos culture helped in showing wheat callus response towards ABA (Morris et al., 1989).
Study of floral developmental mechanism in wheat can be used by immature embryo culture (Bi-Hua et al., 2003).
