Resistance (sensitivity) of some rapeseed genotypes to Peronospora parasitica under field conditions

Abstract

Peronospora parasitica is the causal agent of downy mildew in the rapeseed. The symptoms occur in the form of chlorotic spots. First symptoms occur at the cotyledon stage. Infected plants have delayed growth and some die in the course of growing season. Although the parasite is considered as minor in our country, it is fairly intensive on some lines when conditions are favorable for parasite’s development. In this study we assessed several genotypes of winter rapeseed developed at Institute of Field and Vegetable Crops for resistance to downy mildew (P. parasitica). Assessment was made on the scale from 0 to 4 at the stage of 5 permanent leaves. The genotypes were found to differ in reaction. Genotype 171 was highly sensitive while genotype 178 exhibited the highest resistance.

Plamenjaču uljane repice prouzrokuje Peronospora parasitica. Simptomi na biljkama se javljaju u vidu pegavosti. Prva pojava simtoma se može zapaziti već u stadijumu kotiledona u vidu hlorotičnih pega. Napadnute biljke zaostaju u porastu, a neke tokom vegetacije propadnu. Iako za sada parazit ne prouzrokuje značajnije štete kod nas, ipak na nekim linijama u povoljnijim uslovima za razvoj parazita pojava pega je intenzivnija. U ovom radu rađena je ocena otpornosti na plamenjaču (P. parasitica) različitih genotipova ozime uljane repice stvorenih u Institutu za ratarstvo i povrtarstvo. Ocena je rađena po skali od 0 do 4 u fazi pet stalnih listova. Na osnovu rezultata ispitivanja ustanovljena je razlika u otpornosti između proučavanih genotipova. Genotip 171 je bio veoma osetljiv na parazitnu gljivu Peronospora parasitica, a najotporniji je bio genotip 178.