Fluorescent reaction of wheat seedlings when infected by <i>Bipolaris sorokiniana</i>

Abstract

Results of the studies of photosynthetic activity of seedlings of three varieties of spring soft wheat grown under controlled climatic conditions and their response to infection with the pathogen of common root rot of cereals Bipolaris sorokiniana Shoem. by chlorophyll fluorescence (ChlF) parameters are presented. Chlorophyll fluorescence was recorded with a Dual-PAM-100/F fluorimeter in the mode of recording slow kinetics of dark induction curves with pulse saturation analysis (Slow Kinetics). The studies were conducted in 2021, 2022. The varietal specificity of formation of adaptive reactions of 10–16-day-old spring wheat seedlings under infection with B. sorokiniana (5000 conidia per grain) according to the daily dynamics of the ChlF parameters was established. The information content of the ChlF parameters Y(II), ETR, qP, Fv/Fm, Fv/F0, Y(NPQ), qN and Y(NО) as biomarkers for assessing pathogen resistance of the varieties at the level of photosynthetic apparatus was confirmed. The response of the more resistant wheat varieties Novosibirskaya 29 and Sibirskaya 21 to the pathogen introduction was less pronounced compared to the less resistant variety Novosibirskaya 41. The more resistant varieties exhibited the smallest changes in the ChlF parameters relative to the control. The greatest inter-variety differences in infection with B. sorokiniana (from 1.9 to 8.6 times) were manifested in 16-day-old seedlings. The level of the photosynthetic activity in the formation of adaptive reactions during the pathogenesis of B. sorokiniana can serve as a criterion of stress resistance, which will make it possible to conduct complex studies on modeling the system plant – host – pathogen, to assess the primary nonspecific reactions and adaptive components of stress resistance of spring wheat varieties.