CALLUS CULTURE TECHNOLOGY OF SPRING SOFT WHEAT STRESS TOLERANT VARIETIES SELECTION - Biochemistry and Biotechnology: Research and Development - page 55

Table 5. Growth parameters of Minusa, KS-1607 and their regenerants plantlets under
salt stress conditions (NaCl 1,68%)
Genotype Root length Σ, mm Shoot length, mm Root weight, mg Shoot weight, mg
control NaCl control NaCl control NaCl control NaCl
Minusa 423,1 61,9 151 21,8 78,6 28,7 85,6 31,3
RS(Minusa)3 317*** 89,3** 121** 35,4*** 57,9*** 30,2 72,8* 34,9
RS(Minusa)9 469 77,6 158 40,8*** 89,5 24,4 89,8 41,6**
KS-1607 296 35,5 129 7,59 83,0 15,9 105 15,2
RS(KS-1607)1 292 62,7** 154 31,8*** 84,0 24,5** 98,9 34,0***
RS(KS-1607)2 387** 46,1 137 14,7 95,0 18,2 95,6 24,8*
RS(KS-1607)3 345 38,6 128 10,1 91,4 18,8 99,7 14,0
Significant difference between regenerant and parental variety * - Р≤0,1; ** - Р≤0,05; *** - Р≤0,01.
Immature embryos were used in research. So the question of their age, which can ensure
the highest regenerant yield, appeared. The embryo age didn`t influence on callus induction
frequency.
But the quantity of samples with organogenesis was 2-2,5 time higher in culture of more
mature embryos than in three week age ones under these conditions. As the result the
embryos taken at 20-21 days after the beginning of the earing have showed higher
morphogenesis and regenerant yield in comparison with the material that had been taken at
milky-wax ripeness stage (27-28 days) (Table 2). It seems that less differentiated embryos are
more sensitive to exogenous hormones level change in comparison with more mature
material. As the result the less mature embryos almost don`t formed any growing-points
during callusogenesis step. Their calluses easier formed organogenic areas and regenerants
after 2,4-D level decrease on proliferation medium in addition.
Different regeneration media compositions were tried to increase regenerant yield. It was
detected that the media with IAA (1 mg/l) and kinetin (2 mg/l) (no. 13) [[7]] or BAP (2 mg/l)
(b) [[11]] are the best for organogenesis stimulation under nonselective conditions. The
highest regeneration was detected under stress influence at the medium with higher level and
ratio of IAA (1,75 mg/l) and kinetin (10 mg/l) (no. 14) [[9]] (Figure 1).
O PTIMIZATION OF L EVELS OF S ELECTIVE A GENTS
Influence of different levels of NaCl (Table 3) and PEG (Table 4) on wheat callus
proliferation and plant regeneration was investigated to increase effectiveness of stress-
tolerant varieties selection.
NaCl concentration of 0,42% didn`t ensure significant suppression of growth. This aim
was reached by increasing the NaCl level up to 0,84%. The content of salt 1,68% almost
stopped organogenesis and resulted in zero regenerant yield in callus culture of all genotypes
except KS-1607 (Table 3)
PEG is used widely in callus culture drought-tolerant varieties selection [[12], [9], [10],
[2]] .