Pathogenicity and diversity of vegetative compatibility of Fusarium verticillioides

Abstract

Pathogenicity of 10 Fusarium verticillioides isolates, originated from grain of wheat (five isolates) and maize (five isolates), were studied under greenhouse conditions. Based on different parameters of the pathogenicity estimate (a scale for % of nonemerged plants, % of survived plants, plant vigour - the growth and dry weight of roots and epicotyls and disease severity) it was determined that all F. verticillioides isolates expressed a different degree of pathogenicity. According to % of nonemerged plants six three and one F. verticillioides isolates expressed low, moderate and high degree of pathogenicity, respectively. All F. verticillioides isolates reduced the plant survival rate and vigour, while the disease severity ranged from 2.0 to 3.54. Two types of nit mutants, nit1 and NitM, were obtained by the use of the method of vegetative compatibility. The frequency of nit1 mutants was greater (58.79%) than the frequency of NitM mutants (5.77%). A total of 10 vegetative compatibility groups (VCGs) of F. verticillioides were established in the complementation tests. These results point out to a high genetic diversity of F. verticillioides population.

Patogenost 10 izolata F. verticillioides, poreklom iz zrna pšenice (5 izolata) i kukuruza (5 izolata), proučavana je u uslovima staklenika. Na osnovu različitih parametara ocene patogenosti (skala za % neizniklih biljaka, % preživelih biljaka, vigora biljaka - porast i suva težina korena i epikotila, i intenziteta bolesti) ustanovljeno je da su svi ispitivani izolati F. verticillioides ispoljili različit stepen patogenosti. Prema % neizniklih biljaka 6 izolata ispoljilo je nisku, 3 izolata srednju i jedan izolat F. verticillioides visoku patogenost. Svi ispitivani izolati F. verticillioides su prouzrokovali smanjeno preživljavanje i vigor biljaka, sa intenzitetom bolesti od 2.0 do 3.54. Primenom metode vegetativne kompatibilnosti izolovane su dve vrste nit mutanata, nit1 i NitM. Učestalost mutanata nit1 je bila veća (58.79%) u odnosu na NitM mutante (5.77%). U komplementarnim testovima ustanovljeno je 10 vegetativno kompatibilnih grupa (VCG) F. verticillioides što ukazuje na visok genetički diverzitet populacije ovog patogena.