| Barley (Hordeum sativum) is the forth cereal crops in the world's cultivated area and it isthe important edible and forage crops in Tibet and northwestern regions of China. However,the drought often happens in growing season, especially in early growth period when theanti-adversity ability is weak, which has seriously impacts on the normal physiologicalactivities and morphology exhibition thus leading to yield reduction and quality loss. It is akey to restrict China's barley production when the drought frequencies and scope of droughtoccurred frequently in recent years. Therefore, it is a way to discover the better genes of watersaving and drought-resistant materials of barley which could improve barley yield and quality,which have a more significance for enhancing farmers' income, alleviating the water crisisand ensuring the national food security, ecological security and social sustainable.This experiment analyzes the drought resistance by research the changes of growthconditions and physiological feature of different barley materials in the early growth stagethough PEG osmotic stress simulated drought. The whole test was divided into two parts: oneis the changes of growth conditions and physiological feature when the barley germination,the other is the changes of the seedling's physiological features for barley materials.The drought tolerance indicators were measured by the germination energy, germinationrate, plant height, root length, seedling fresh and dry weight when the seed germination,proline content (pro), malondialdehyde content (MDA), activity of peroxides (POD), therelative conductivity of the leaves of different barley seedlings by different PEG osmoticstress. That is drought tolerance coefficient of germination rate, germination index of droughttolerance coefficient, drought tolerance coefficient of seed vigor, plant height, root length,they are reduced with PEG osmotic stress increase, proline (pro), malondialdehyde (MDA),activity of peroxides (POD) and the relative conductivity increase with PEG Osmotic stressincreases, the relative water content, chlorophyll a and chlorophyll b content decreased withPEG osmotic stress increase, the soluble sugar content first increased then decreased.Chlorophyll fluorescence parameters Fm and Fv, Fv/Fm and the∮the PS II as the stress increases, showing a downward trend, F0, of NPQ, qP and ETR With the increased stressincrease,and the decline range was different in variance species. Though calculating themembership function value of the different indicators of drought tolerance analysis shows thatthe strong drought resistance varieties are Ganpi No.3and the Fawaweite; drought-typevarieties are95-83, Xiyin No.2,2136, Ganpi No.4, D-63and D-76; varieties of drought typeare D-61, Xi'an91-2, D-83, Ha Ruite, D-3and D-22; weak drought type or not droughtresistance varieties are D-45D-26D-88, Yangsimai No.3and D-18;others show Drought typeis Ganpi NO.3,GanpiNo.4, and Xiyin No.2; varieties of drought type are Xi'an91-2, Ha Ruiteand D-22; type of weak drought or not drought resistance varieties Yangsimai No.3and D-18.Though the average of various indicators and drought resistance of the membershipfunction correlation analysis shows that the indicators of barley germination rate of thedrought coefficient, the germination index of drought tolerance coefficient, plant height,relative conductivity, peroxides activity and chlorophyll fluorescence parameters existence ofhighly significant correlation with the average value of the variable fluorescence and droughtresistance of the membership function; significant correlation exists with the average relativewater content, proline content, F0,∮PS II, NPQ and qP and Drought Tolerance inmembership function, So, these indicators can be used as the identification indexes evaluatingdrought resistance assessments seedlings of different barley varieties. |
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