Heritabilnost otpornosti pšenice na fuzarijsku palež klasa u uvjetima umjetne i prirodne infekcije

Abstract

Fusarijska palež klasa (FHB), uzrokovana gljivom Fusarium graminearum (teleomorfGibberella zeae (Schw.) Petch) trenutno je jedna od najopasnijih bolesti pšenice u svijetu. Štete od zaraze se očituju u smanjenju prinosa zrna te nakupljanju za zdravlje ljudi i životinja štetnih mikotoksina. Razvoj otpornih kultivara se smatra najučinkovitijim načinom kontrole. U oplemenjivanju na otpornost na FHB koriste se različite metode umjetne inokulacije klasa među kojima je najčešće korištenja metoda nanošenja inokuluma na klasove pšenice prskanjem u fazi cvatnje (sprej metoda). Ova metoda je tehnički i radno zahtjevna pa se kao alternativa predlaže površinsko razbacivanje zaražene kukuruzovine nakon nicanja pšenice (inokulacija kukuruzovinom). Kod izbora prikladne metode umjetne inokulacije oplemenjivaču je osimcijene i vremena potrebnog za njenu implementaciju važna i visoka heritabilnost metode radi dobivanja pouzdanih i ponovljivih rezultata. Cilj rada je bio u usporediti heritabilnost dviju metoda umjetne infekcije i metode prirodne infekcije uzročnikom fuzarijske paleži klasa pšenice te procijeniti fenotipske korelacije između navedenih metoda. U 2014/2015.vegetacijskoj sezoni 18 oplemenjivačkih linija iz Bc instituta Zagreb i 5 standarda različite otpornosti na FHB uzgajano je u uvjetima umjetne infekcije uzročnicima FHB kao i uvjetima prirodne infekcije. Signifikantne razlike među genotipovima utvrđene se za indeks zaraženosti klasa (VRI) kod sve tri metode infekcije dok su za Fuzarijem oštećena zrna (FDK) razlike bile signifikantne samo za dvije metode umjetne infekcije. Za obje ocjene VRI i FDK utvrđena je signifikantna interakcija između metode i genotipa. Nekoliko oplemenjivačkih linija pokazivalo je otpornost na FHB na razini otpornih standarda. Za VRI utvrđene su jake pozitivne korelacije (0,85-0,91) između svih triju metoda, dok je u slučaju FDK jaka korelacija utvrđena samo između dviju metoda umjetne infekcije (0,86). Kod sve tri metode infekcije heritabilnost je bila znatno veća za VRI (0,59-0,95) nego za FDK (0,04-0,54). Također, heritabilnost kako za VRI tako i FDK bila je znatno veća kod dviju metoda umjetne infekcije u usporedbi s heritabilnošću u uvjetima prirodne infekcije.Fusarium blight (FHB), caused by the fungus Fusarium graminearum (Gibberella zeaeteleomorph (Schw.) Petch) is currently one of the most dangerous diseases of wheat in theworld. The damage caused by the infection manifests in the reduction of grain yield and accumulation of mycotoxins harmful for human and animal health. The development of resistant cultivars is considered to be the most effective method of disease control. In breeding for resistance to FHB different methods of artificial ear inoculation have been used including the most common method of spraying of inoculum on wheat ears in the flowering stage (spraymethod). This method is technically and labor demanding and as an alternative a surface scattering of infected maize stalks on the soil surface after the emergence of wheat have also been proposed (maize stalk method). When choosing an appropriate method of artificial inoculation in addition to cost and time required for its implementation, a high heritability of the method is required to obtain reliable and reproducible results. The aim of the study was, in a field experiment including 18 breeding lines from Bc Institute Zagreb and 5 checks with different levels of FHB resistance, to compare the heritability of two methods of artificial inoculation (spray and maize stalk methods) and a method of natural infection with fungi that causes FHB of wheat and to assess the phenotypic correlation between these methods. Significant differences among genotypes was determined for Visual Rating Index (VRI) for all three methods of infection while for the percent Fusarium damaged kernels (FDK) differences were significant only for two methods of artificial inoculation. For both ratings VRI and FDKa significant interaction between method and genotype was determined. The level of resistance to FHB in several breeding lines was similar to the resistant standards. For VRI a strong positive correlation (0.85 to 0.91) between all three methods was found, whereas in the case of FDKstrong correlation was observed only between the two methods of artificial inoculation (0.86). For all three methods heritability was significantly higher for VRI (0.59 to 0.95) than for FDK(0.04 to 0.54). Also, the heritability for both SAI and FDK was significantly higher for the two methods of artificial inoculation than for natural infection