Chlorophyll fluorescence indices as an effective parameter to study spring barley resistance to abiotic factors

The growing need to improve agricultural production in changing climatic conditions necessitates the acceleration of development of new stress-resistant varieties. The lines obtained as a result of breeding require rapid and highquality estimation for resistance to various impacts. Due to the high degree of correlation between the activity of a photosynthetic apparatus and a plant, the efficiency of photosynthesis is one of the most indicative parameters of the state of a plant. There has been shown above that chlorophyll fluorescence parameters can be effectively used to screen new barley lines for drought resistance. The purpose of the current work was to test new barley lines for resistance to drought and salt stress under controlled conditions based on the parameters of photosynthesis at the early stages of plant development. The study was conducted on the promising lines ‘11027’ (Zernogradsky 1895), ‘11023’ (Zernogradsky 1898) and a new variety ‘Feniks’ developed by the FSBSI “Agricultural Research Center “Donskoy”. Drought conditions were created by stopping watering the plants from the 14th day until the end of the trial. To simulate salt stress, the 14-day old plants were watered with a 600 mM salt solution every other day. The parameters of photosynthesis and transpiration intensity were recorded daily, starting from the 12-day old seedlings. Morphometric parameters were measured once when the plants were 30 days old. There has been shown that under stress-free conditions, the morphometric parameters and photosynthetic activity of the line ‘11027’ and the variety ‘Feniks’ are higher than similar indicators of the line ‘11023’. The variety ‘Feniks’ turned out to be the most drought-resistant. The line ‘11023’ has demonstrated the greatest salt stress resistance. The line ‘11027’ has demonstrated the lowest resistance to both abiotic effects, showing the earliest changes in photosynthetic indices. There has been noted that chlorophyll fluorescence indices allow obtaining statistically significant differences between the studied lines using a smaller number of individual plants than is required to accumulate morphometric data, which is an important advantage of the method in breeding.