Induction and cryopreservation of somaclonal variation in wheat and rice
1989
Bajaj, Y.P.S. (Biotechnology in Agriculture and Forestry, New Friends Colony, New Delhi (India))
The dual problem of the depletion of genetic resources and the loss of native germplasm due to cultivation of few improved cultivars over large areas has led to the disappearance of the genetic diversity in many crops. Thus, biotechnological approaches are being evaluated for the induction of genetic variability and the conservation of germplasm. In this regards, studies on in vitro culture combined with cryopreservation have yielded some valuable information for their use in wheat and rice improvement programs. In vitro cultures have been observed to exhibit somaclonal and gametoclonal variation and the regenerants show heritable changes. The callus-derived plants showed a wide range of morphological traits. Wheat plants with larger spikes, better yield, and gliadin variation have been obtained. Likewise, rice variants with higher protein content, resistance to Xanthomonas oryzae, and tolerance to salt have been reported. The regeneration of complete plants from frozen (-196 deg C) zygotic and pollen embryos of wheat and rice establish the use of cryopreservation for the conservation of somaclonal and gametoclonal variants. It is highly desirable to incorporate the in vitro-generate variability in wheat and rice improvement programs that may enable the early release of improved cultivars. Cryopreservation would further help to conserve the variant cell lines and tissues.
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