Genetics Lab., Biology Department, Wuhan University, Wuchang, Hubei, China
The tissue culture method can be used for producing and propagating primary
trisomics in rice. The materials we use are diploid and tetraploid strains of a
rice cultivar, Guangluai 4. For sterilization, the seeds are immersed in 70%
alcohol and then in 0.1% mercuric chloride solution for 10 minutes, and are
finally with sterile water 3 to 5 times. The N6 medium with addition of 2,4-D
(2mg/1), 4.5% suchrose and 0.7% agar is used for callus induction and the MS
medium with an addition of NAA (0.5mg/1), KT (2mg/1), 3% sucrose and 0.7% agar
is used for plantlet differentiation. The results have shown that: 1) Triploids
were produced by culturing 4nx2n young embryos and immature endosperms of 2n
plants. 2) The culture of young panicles of a triploid plant at the 2nd, 3rd,
4th and 5th stages is useful for multiplication of the triploid plant. 3) The
seeds produced by 3nx2n crosses are cultured to induce somatic-cell callus
formation, from which different types of primary trisomics can be distinguished
by karyotype analysis. 4) The different types of primary trisomics can be
maintained in test tubes by culturing their young panicles.
References
Ling, D.H., W.Y. Chen, M.F. Chen and Z.R. Ma, 1983. Direct development of plantlets from immature panicles of rice in vitro. Plant Cell Reports 2(4): 172-174.
Kurata, N. and T. Omura, 1978. Karyotype analysis in rice, 1. A new method for identifying all chromosome pairs. Jpn. J. Genet. 53(4):251-255.
Nakano, H., T. Tashiro and E. Maeda, 1975. Plant differentiation in callus tissue induced from immature endosperm of Oryza sativa L. Z. Pflanzenphysoiol. 76(5): 444-449.