Evaluation of some factors affecting in vitro micropropagation of few seeded fruit guava trees

الملخص EN

This study was carried out during the period from 2013 to 2016 in the Plant Tissue Culture Laboratory Hort.

Dept., Fac.

Agric., Zagazig University, Egypt to create a protocol for propagating few seeded fruit guava trees throughout the various stages of tissue culture technique.

During the establishment stage, explants (nodal explants and shoot tips) were excised from 6- monthold seedlings grown in the green house.

The excised explants were cultured in Murashige and Skoog (MS) medium supplemented with 1mg/l benzyl adenine (BA) combined with 100 mg/l polyvinylpyrrelidone (PVP).

Results showed that nodal explants proved to be better than shoot tips concerning growth parameters.

Different BA concentrations i.e.

0.0, 0.5, 1 or 2 mg/l proved the efficiency of 2mg/l BA for shoot proliferation from nodal explants, followed by 1mg/l BA.

Inoculation nodal explants during different dates revealed that spring season (mid April) produced the best growth parameters.

Obtained shoots about 1cm length from establishment stage were cultured in MS medium provided with BA or kinetin (Kin.), at different concentrations (0.0, 0.5, 1, 2, 4, or 6 mg/l).

Results showed that BA recorded the highest multiplication rate compared with Kin., which produced one shoot, only, whereas 2mg/l BA gave the highest number of shoots/ explant (10.62 shoots/ explant).

Addition of sucrose at 20, 30 or 40 g/l to MS medium supported with 2mg/l BA enhanced the efficiency of 40 g/l sucrose concerning number of shoots/explant (12 shoots/explant).

The combination of 2mg/l BA and different auxins (NAA, IAA or IBA) at low concentrations showed that 2 mg/l BA combined with 0.5 mg/l IBA gave the highest number of shoots/ explant (11.20 shoots/ explant).

During rooting stage, using each of NAA, IBA or IAA at 0, 1, 2 or 4 mg/l in MS medium, resulted in shoot rooting.

Although NAA resulted in more number of roots/ shoot, IBA at 1 or 2 mg/l was adequate for producing better rooting shoots for acclimatization stage.

The obtained rooted plantlets could be successfully acclimatized in peat moss medium incorporated with sand at 1:2 (V/V), since it gave 100% survival