Studies On Waterlogging Tolerance Of Barley

145 barley varieties (lines) were waterlogged during early tillering stage(15 days),late tillering stage(lOdays) and booting stage(10 days). The responses of both agronomic traits and photosynthesis traits to waterlogging were analysed. Results showed that:1.Different traits, ecotype and origin had different responses to waterlogging. Yield characters were the most sensitive followed by plant type, ear characters of the main stem. Chlorophyll content at booting stage (CHL2) was more sensitive than chlorophyll content at seedling stage (CHL1). 6-row barley showed to be more sensitive than 2-row barley in some traits such as grains and ear length of the main stem while contrary results were observed in the number of green leaves of the main stem at booting stage. Mulled barley showed better tolerance than naked barley in grains per plant and dry weight per plant. Barley varieties from the middle and lower Yangtse River valley zone were more tolerant to waterlogging than these from other areas in China.2.Waterlogging-tolerance of barley could be expressed by 4 common factors, i.e. yield, plant type, ear characters of the main stem and photosynthesis. There were significant canonical correlations between yield factor and other three factors.3.Different traits had different genetic potential. The number of green leaves and ear length of the main stem and yield per plant had higher heritability while the heritability of grains per plant and ears per plant was relatively low. The genetic coefficients of variation of yield characters and the number of green leaves were higher than that of plant height and CHL2.4.There were significant correlations among waterlogging-tolerance indices of yield characters. Varieties showed significant differences in waterlogging-tolerance indices of both plant height and yield characters. Plant height had significant correlations with all the yield characters. Both ears per plant and plant height could be used as an index in selecting barely waterlogging-tolerance.5.Ward's method and subfunction method were suitable for the evaluation or classification of waterlogging-tolerance of barley germplasm.6.Thirty four varieties (lines) had shown high waterlogging-tolerance, these included new cultivar Yangpi 1, new lines Yan95168 et al. 12 varieties (i.e. Shengxianhongjingsileng and S096 et al) had good quality or disease resistance. Sixty five varieties (lines) showed medium waterlogging-tolerance with 9 varieties having good quality or disease resistance. These included Yivvuhongkesileng. Zhenongda 3, Yangnongpi 2 and K.A-4B. Thirty two varieties (lines), such as Ziqingke and Hiproly, were very susceptible to waterlogging.