Advances in Biology & Earth Sciences

Verticillium wilt (VW) is an important and widespread disease of cotton and once established is long-lived in soil and difficult to manage. Non-defoliating pathotype of Verticillium dahliae fungi is extremely virulent. Identification and development of new cotton lines with increased VW resistance is the only effective method of disease management. Chromosome substitution (CS) lines are unique germplasm with identical genetic background from TM-1 double haploid line and one introgressed chromosome from G. barbadense specie which considered having natural resistance to VW. This paper discusses results of first evaluation of VW resistance of 17 CS lines, their parental lines and five reniform nematode resistant lines using a controlled environment bioassay. Chromosome substitution lines displayed contrasting levels of resistance to VD11 pathotype of VW. Five CS lines and five nematode resistant lines demonstrated high level (0.4-0.6DSI) of resistance after inoculation by spore suspension of pathogen. Based on results of membrane damage assay M713 Ren5 line showed high resistance to pathogen inoculum. The comparative analysis of such unique genetic materials as chromosome substitution lines greatly empowers the detection of chromosomal effects on disease resistance. Crosses between identified VW resistant CS lines can provide unique opportunity to combine alleles associated with disease resistance from two substituted chromosome in one genome.