Protocols for Micropropagation of Woody Trees and Fruits

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K. PRUSKI
can also be used (Table 2). Prediction of the number of rosettes per explants is an
important element in multiplication scheduling for both Mongolian and Nanking
cherry cultures.
Table 2. Effects of growth regulators on culture initiation and performance (rosette
production) and % survival of Nanking cherry and Mongolian cherry (Pruski et al., 2005).
Treatment
Number of rosettes per established culture
Mongolian cherry Nanking cherry
NAA 0.5 µM + BA 4.4 µM 1.00 (39 1 , 90% 2 ) 0.97 (28, 90%)
NAA 0.5 µM + BA 8.9 µM 1.40 (45, 93%) 1.20 (37, 96%)
IBA 0.5 µM + BA 4.4 µM 1.30 (30, 96%) 0.93 (27, 80%)
IBA 0.5 µM + BA 8.9 µM 1.50 (42, 100%) 1.23 (36, 86%)
The results are given as the mean number of rosettes per explant. In brackets are the total
number of produced rosettes and the percentage survival; n = 30 per each treatment and species.
1
Total number of rosettes produced out of 30 explants.
2
Survival percentage of cultures.
In general, the Nanking cherry cultures are more difficult to establish than the
Mongolian cherry. The percentage survival varied from 80% to 96% while the
Mongolian cherry was from 90% to 100% being the highest on media recommended
above. Rosettes produced on initiation medium (Figure 2B) are placed on solid
media in Magenta GA7 vessels for multiplication. In our experiments, shoot
proliferation was conducted on MSMO medium with various concentrations of BA
and TDZ. Following a number of repetitions we were able to determine optimal
concentrations of BA for multiplication of both Mongolian and Nanking cherries.
For each species, we calculated the value of BA concentration that maximizes the
number of good quality shoots produced by proliferating cultures. Proliferating
cultures and their rosettes are shown in Figure 2C. Summary of the regression
analysis for shoot proliferation responses as affected by BA concentration is
presented in Figure 3.
Controls (zero BA) usually produce ca. 1.5–2 shoots, approx. 25 mm long per
rosette in both species. With increasing BA concentration in the medium, more but
shorter shoots are produced. Above BA concentration of 15.00 µM number of shoots
per culture in both species starts to decrease. With increasing BA concentration in
the medium length of shoots decreases. Hyperhydricity starts to show on media with
high concentrations of BA where cultures become dark green, having short and
fragile shoots with poorly developed leaves. In related species, shoot deformations
of cultures grown on media with a high content of BA (22.5 µM and above) are
known and were reported by Linebeger (1983) for Prunus × Hally Jolivette, Pruski
et al. (1990) for Saskatoon berry (Amelanchier alnifolia Nutt.), and Pruski et al.
(2000) for chokecherry (P. virginiana L.) and pincherry (P. pensylvanica L.). For
both Mongolian and Nanking cherries, BA concentrations 8–15 µM are optimal for