SOMACLONAL VARIATION IN PROGENIES OF PEA PLANTS REGENERATED FROM TISSUE CULTURES

PNL Volume 21 1989 RESEARCH REPORTS

SOMACLONAL VARIATION IN PROGENIES OF PEA PLANTS REGENERATED FROM TISSUE CULTURES¹

Cardi, T. C.S. Miglioramento Genetico Ortaggi

CNR, Portici, Italy

Somaclonal variation is a well known phenomenon in plants regenerated from tissue cultures (6). In pea, cytological variation was reported both in undifferentiated cultures and regenerated plants (4, 8, 9, 11). Morphological and physiological variation was observed in plants regenerated from long-term callus cultures (2,5).

Immature primary scales and leaflets from 3-4 day-old seedlings of the cv. Century were cultured basically according to the procedure of Mroginski and Kartha (7), with modifications in some experiments. Regenerated shoots were rooted (3) and successively transferred to a greenhouse. On the whole it was possible to analyze the progenies of 24 R₁ plants.

In 18 R₂ families no variation was observed. R₁ plants were regenerated after 3 months of culture and the results agree with those reported by Rubluo et al. (10). The other 6 R₁ plants were regenerated from cultures grown in vitro for three months on a MS medium with NAA and BAP at 10 mkm each, subcultured for two months on the same basal medium with the NAA level reduced to 0.1 mkm, and finally transferred for a further 45 days on a basal medium without growth regulators. Three out of these 6 plants segregated for chlorophyll and morphological mutations (Table 1). One of them appeared as a chlorina-type mutation, another had funnel-shaped and laciniate leaflets resembling the lac mutant described by Blixt (1), while a third one showed an increased number of basal branches and reduced plant growth and leaflet size. From the first two segregation ratios a monogenic recessive mutation can be hypothesized, whereas in the third case a deficit of recessives was observed. Work is in progress to better characterize the genetic basis of the mutations observed.

1. Blixt, S. 1978. PNL 10:80-101.

2. Ezhova, T.A., A.M. Bagrova, and S.A. Gostimski. 1985. PNL 17:8-9,

3. Filippone, E. 1985. PNL 17:12.

4. Ghosh, P. and A.K. Sharma. 1979. Caryologia 32: 419-424.

5. Hussey, G. and H.V. Gunn. 1984. Plant Sci. Lett. 37: 143-148.

6. Larkin, P.J. and W.R. Scowcroft. 1981. Theor. Appl. Genet. 60: 197-214.

7. Mroginski, L.A. and K.K. Kartha. 1981. Plant Cell Rep. 1:64-66.

8. Natali, L. and A. Cavallini. 1987. Plant Breeding 99:172-176.

9. Natali, L. and A. Cavallini. 1987. Protoplasma 141:121-125.

10. Rubluo, A., K.K. Kartha, L.A. Mroginski, and J. Dick. 1984. J. Plant Physiol. 117:119-130.

11. Torrey, J.G. 1967. Physiol. Plant. 20:265-275.

Contribution no. 37 from C.S. Miglioramento Genetico Ortaggi, CNR



	6 PNL Volume 21 1989 RESEARCH REPORTS

	Table 1. Phenotype of mutant plants and segregation ratios in three R₂ progenies.

	Mutant, Phenotype Number of Number of R₂ X² R₂ plants mutant plants (3:1)

	A chlorina 16 4 0 NS B laciniata-type 18 2 1.85 NS C increased number of basal 34 2 6.63 ** branches; reduced plant growth and leaflet size

	NS not significant; ** P = 0.01

	*****



	PNL Volume 21 1989 RESEARCH REPORTS	5

	SOMACLONAL VARIATION IN PROGENIES OF PEA PLANTS REGENERATED FROM TISSUE CULTURES¹ Cardi, T. C.S. Miglioramento Genetico Ortaggi CNR, Portici, Italy Somaclonal variation is a well known phenomenon in plants regenerated from tissue cultures (6). In pea, cytological variation was reported both in undifferentiated cultures and regenerated plants (4, 8, 9, 11). Morphological and physiological variation was observed in plants regenerated from long-term callus cultures (2,5). Immature primary scales and leaflets from 3-4 day-old seedlings of the cv. Century were cultured basically according to the procedure of Mroginski and Kartha (7), with modifications in some experiments. Regenerated shoots were rooted (3) and successively transferred to a greenhouse. On the whole it was possible to analyze the progenies of 24 R₁ plants. In 18 R₂ families no variation was observed. R₁ plants were regenerated after 3 months of culture and the results agree with those reported by Rubluo et al. (10). The other 6 R₁ plants were regenerated from cultures grown in vitro for three months on a MS medium with NAA and BAP at 10 mkm each, subcultured for two months on the same basal medium with the NAA level reduced to 0.1 mkm, and finally transferred for a further 45 days on a basal medium without growth regulators. Three out of these 6 plants segregated for chlorophyll and morphological mutations (Table 1). One of them appeared as a chlorina-type mutation, another had funnel-shaped and laciniate leaflets resembling the lac mutant described by Blixt (1), while a third one showed an increased number of basal branches and reduced plant growth and leaflet size. From the first two segregation ratios a monogenic recessive mutation can be hypothesized, whereas in the third case a deficit of recessives was observed. Work is in progress to better characterize the genetic basis of the mutations observed.

	1. Blixt, S. 1978. PNL 10:80-101. 2. Ezhova, T.A., A.M. Bagrova, and S.A. Gostimski. 1985. PNL 17:8-9, 3. Filippone, E. 1985. PNL 17:12. 4. Ghosh, P. and A.K. Sharma. 1979. Caryologia 32: 419-424. 5. Hussey, G. and H.V. Gunn. 1984. Plant Sci. Lett. 37: 143-148. 6. Larkin, P.J. and W.R. Scowcroft. 1981. Theor. Appl. Genet. 60: 197-214. 7. Mroginski, L.A. and K.K. Kartha. 1981. Plant Cell Rep. 1:64-66. 8. Natali, L. and A. Cavallini. 1987. Plant Breeding 99:172-176. 9. Natali, L. and A. Cavallini. 1987. Protoplasma 141:121-125. 10. Rubluo, A., K.K. Kartha, L.A. Mroginski, and J. Dick. 1984. J. Plant Physiol. 117:119-130. 11. Torrey, J.G. 1967. Physiol. Plant. 20:265-275.

	Contribution no. 37 from C.S. Miglioramento Genetico Ortaggi, CNR