measurements of chromosome aberration at tomato plants
measurements of chromosome aberration at tomato plants
measurements of chromosome aberration at tomato plants
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M<strong>at</strong>erial and MethodsThe biological m<strong>at</strong>erial is represented from 4genotypes <strong>of</strong> tom<strong>at</strong>oes (Lycopersicon esculentum Mill.)from Vegetable Research and Development St<strong>at</strong>ionBacau, Romania. The seeds were utilized for the “invitro” multiplic<strong>at</strong>ion <strong>of</strong> these valuable genotypes andthe meristem<strong>at</strong>ic root tips were excised from the “invitro” plantlets regener<strong>at</strong>ed on D1-D3 variants,characterized through the presence <strong>of</strong> BAP and Kinetinalone or in associ<strong>at</strong>ion with IAA – table 1.Experimental variants utilized in the cytogenetic studies <strong>at</strong> Lycopersicon esculentum Mill.Components D0 D1 D2 D3Macro elementsMS, 1962Microelements MS, 1962Vitamins B 5BAP seeds germin<strong>at</strong>ed “ex 2,0 mg/l - 1,5 mg/lKinetin vitro”- 2 mg/l -IAA - - 0,5 mg/lSucrose 3% 3% 3%Agar 8 ‰ 8 ‰ 8 ‰Table 1The control variant is represented by <strong>plants</strong>germin<strong>at</strong>ed “ex vitro” in Petri dishes.The cytogenetic studies were accomplished inmeristem<strong>at</strong>ic root cells, stained in Carnoy fixingsolution for 24 hours <strong>at</strong> 4 0 C then hydrolyzed with HClfor 7 minutes and colored with the basic coloringsolution Carr. The root meristems were displayed usingsquash technique and for each genotype and variant6000 cells were counted.Results and DiscussionsThe objective <strong>of</strong> the present study was todetermine whether or not the <strong>plants</strong> regener<strong>at</strong>ed fromin vitro culture presents alter<strong>at</strong>ion in their geneticstructure. Thus, we tested the influence <strong>of</strong> mediumculture composition over the <strong>chromosome</strong>s structures.The cytogenetical studies accomplished in the presentstudy demonstr<strong>at</strong>e th<strong>at</strong> the cultiv<strong>at</strong>ion <strong>of</strong> tom<strong>at</strong>oesshoot tips on nutritive medium modified with Kinetinand BAP allows the regener<strong>at</strong>ion <strong>of</strong> new <strong>plants</strong> with astable genetic m<strong>at</strong>erial th<strong>at</strong> shows little geneticvariability. This variability manifested <strong>at</strong> cellular levelthrough the different types <strong>of</strong> chromosomalabnormalities does not exceed the n<strong>at</strong>ural variabilitypresent also on <strong>plants</strong> germin<strong>at</strong>ed in n<strong>at</strong>ural conditions.The results obtained are presented in tables 2, 3, 4 andfigures 1, 2, 3.Table 2Types and frequency <strong>of</strong> chromosomal <strong>aberr<strong>at</strong>ion</strong>s observed in root meristem<strong>at</strong>ic cells - genotype MonoromVariant Total no<strong>of</strong> cells% Prophases withanomalies%Metaphaseswith anomalies%A+T withanomaliesOther typesD0 5745 0,65 0,83 0,88 1,19D1 6078 0,23 0,24 0,54 0,32D2 5974 0,12 0,32 0,41 0,28D3 6298 0,21 0,49 0,68 0,59275