Abstract:
The purpose of this study was to screen and assess ten new lines of cotton Gossypium barbadense and their F1 and F2 progenies to Fusarium Wilt Disease which caused by Fusarium Oxysporum f.sp vainfectum. The disease is known as seed borne and it can be dispersed in soil and crop residues attached to vehicles and machinery and carried in irrigation and flood water. A field and greenhouse experiments were conducted at Gezira Reseach Station Farm (GRSF) during season 2007 to 2010. Tested lines and check varieties were artificially inoculated using dipping root method in the green house experiment whereas sick plot was used to infect sown seeds in field experiments. The results showed that Domain Sakel, Huda and convential Barakat were the most susceptible genotypes, while the standard variety Barakat 90 showed a high level of resistance (33.3%) Sp-21 (44.4%), IS3(50%), SPA-9(50%) and IS10-1(44.4%) showed intermediate level of resistance (IR).The high level of resistance were recorded in F2 generations of IM14(33%) and IMY1 (37%). There was no resistance in F2 generation of IS3 (76%), while low resistance level was showed in F1 generation of SPA-9 (66.9%). F1 generations of Barakat S (42%) , IMYI (60%), IM14 (50%), SP-7 (55%), IMB-9(54%), and SP-9(58%), showed intermediate resistance as well as IS-10(42%), IMB-9(46%), and SP-21(50%) in F2 generations. F1 generation of IS21 also gave intermediate level of resistance (44%). Low resistance levels were showed in F1 generations of IS3 (76%), IS10-1 (79%) and IS-10 (66.7%). In some cases modifiers or non allelic gene (s) interaction could have contributed to the resistance. It is clear that the genes for disease resistance resulted from spontaneous and induced mutations are different, more dominant and consistent. From the result above experimental lines IM14 and IMY1 could be considered as a source of resistance because the loci might be positively changed by gamma rays, they were better than Barakat 90 and Barakat S. The resistance to Fusarium Wilt in resistant parents used is controlled by two or more genes with a degree of dominance.
