Chlorophyll fluorescence of wheat leaves when infected with Bipolaris sorokiniana

Abstract

For three spring wheat cultivars, characteristics of adaptive reaction to cereal root rot pathogen Bipolaris sorokiniana Shoem. infection are found by laboratory experiments using chlorophyll fluorecence parameter (ChlF) dynamics of 10-16 day old seedlings. Such ChlF parameters as Y(II), ETR, qP, Fv / Fm, Fv / Fо, Y(NPQ), qN and Y(NQ) are verified as informative, being reliable biomarkers for photosynthetic apparatus level pre-symptom estimate of cultivar resistance to the pathogen. For more resistant cultivars Novosibirskaya 29 and Sibirskaya 21, the reaction to the pathogen invasion appeared to be less expressed compared to less resistant cultivar Novosibiskaya 41. More resistant cultivars have the smallest ChlF parameter changes compared to the control ones. Sixteen day old seedlings infected with B. sorokiniana showed the largest intercultivar differences. The photosynthetic activity level during adaptive reaction to B. sorokiniana pathogenesis can be used as stress resistance criterion for selection material to accelerate its sampling and to increase its effectiveness by early non-perspective sample rejection.