Postepy nauk rolniczych - Instytucja Naukowa - Polska Akademia ...

32 K. Rybka, G. ¯urekEffective use of wateras an obligatory criterion in plant breedingSummaryKey words: stomata, transpiration, drought, water usageDestabilized water balance is difficult to be restored and periodical floods are unableto rebuild it. Improvement of efficiency in water usage in agriculture is possibleby the tightening of melioration systems, by the extension of retention reservoir netsand may be also supported by plant breeding methods. Taking into account the effectiveuse of water into breeding processes, new selection markers should be added todistinct individual plants which keep low respiration rate. Such cultivars should givegood yield along with maintaining low transpiration level in both: optimal andsub-optimal climatic conditions. Presently modern cultivars with improved droughtresistance retain proper turgor under stress conditions by more intense transpiration[9]. Unfortunately, more intense transpiration during the drought period is compatiblewith higher transpiration rate under the optimal weather conditions, what results inlarger amount of water evapotranspirating from the soil.In this review, reducing of water usage by crops has been discussed. Major attentionwas paid to the conductance trait of stomata as a marker suitable for selection ofplants which have good yield and lower transpiration.