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that callus induction and development were obtained in the presence of the lowest level
of 2,4-D.
Table 4. Effect of auxins on calli developed on leaf explants of different genotypes by
the end of fourth week.
Genotypes
Callus development on the media supplemented with
NAA 2,4-D IBA
2.0 4.0 2.0 4.0 2.0 4.0
mgl -1
Graphis 5.00 c 5.00 c 3.80 a 4.14 b 5.00 c 5.00 c
Baccara 5.00 c 5.00 d 4.00 b 3.73 a 4.88 d 4.38 c
2107 5.00 c 5.00 c 4.70 b 4.28 a 4.95 c 4.93 c
Hanka 5.00 c 5.00 c 4.07 b 4.00 b 3.73 a 3.75 a
Hunor 3.60 a 4.06 b 3.94 b 3.86 ab 4.37 c 4.97 d
Janus 4.14 c 3.83 c 2.74 b 1.80 a 4.06 c 4.04 c
M49060 3.50 a 4.00 b 3.37 a 3.51 a 4.00 b 4.03 b
Erbi 4.49 b 3.67 a 3.49 a 3.71 a 4.46 b 4.26 b
Means within row signed by the same letter belong to the same homogeneous group
Presence of NAA and IBA irrespectively of their concentrations was enough to induce
and maintain an intense callus development of leaf explants of cv. Graphis, 2107 and cv
Janus. In the case of cv. Baccara the best results were obtained on media containing IBA
at 2.0 mgl -1 concentration, or NAA in both hormone levels. IBA applied in 4.0 mgl -1
was the best treatment for cv. Hunor, while both levels of IBA were favourable for
M49060 and cv. Erbi. In the case of latter cultivars the effect of NAA was the same
advantageous in concentration of 2.0 mgl -1 or 4.0 mgl -1 for cv. Erbi and M49060,
respectively. Only the cv. Hanka was the genotype, which responded to IBA treatments
by the weakest callus development, while induction of callus development was the most
successful on media with NAA. Even if the 2,4-D is generally used for callus induction
in peas (Gantchev, 1997, Molnár, 1993, ) and in other species (Bayliss & Dunn, 1979,
Arora & Singh, 1978, Conger et al., 1982) we found the other auxins (NAA and IBA) to
be more effective to increase callus forming capacity of the majority of pea genotypes
tested in our experiments.
Our results suggested that callus formation can be induced on all genotypes and by use
of each auxins, although the genotypes required an optimal hormone content in medium
for intensive callus growth. Further research is underway in our laboratory to examine
the effects of different osmotic materials on the rate of callus growth.
REFERENCES
Arora, I.K., Singh, R.N. (1978): Growth hormones and in vitro callus formation of
papaya. Scientia Horticulturae, Vol. 8, Iss. 4, 357-361.
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