Studies On Seedling Growth Rhythm And Physiological On Cold Resistance Of Families Of Euscaphis Konishii

In order to 30 families seedlings of Euscaphis konishii as the research object, to compare the growth and physiological characteristics of seedlings of different families, preliminary screening of good families, and then take their superior family biennial seedlings to the primary artificial low temperature stress processing, research changes in physiological and biochemical indexes of plants under low temperature stress, and using the method of membership function in fuzzy mathematics to the seedling of the overall evaluation of cold resistance, the main results were as follows:(1) The growth rhythm of different families of Euscaphis konishii exhibited consistence. The height and diameter growth rhythm assume the “S” growth curve, the annual growth rhythm can be simulated with Logistic equations.(2) Seedling growth has obvious stage, seedling height growth peak appeared 3 times. the first time in early July, second in early September, and the third times in early October, the second time growth was the biggest; diameter appears four times of growth peak, the largest amount of growth appeared at the end of September. According to the aerial parts of seedling growth, its growth process can be divided into four periods: germination stage, seedling stage, fast-growing stage and hardening stage. The fast-growing stage of seedling growth lasted about 91 d, accounted for about 64.62% of the whole process of growth, diameter growth peak lags behind the seedling growth peak.(3) Photosynthetic rate(Pn) of Euscaphis konishii in the morning around 10 reached the maximum value of the day. The diurnal variation of the Pn exhibited single-range cur. Euscaphis konishii is sensitive to the change of light intensity, the Photosynthetic rate of amplitude in 3.91umol·m-2s-1~ 5.92umol·m-2s-1, leaf SPAD value ranging from 41.8 ~ 57.38.(4) Using the principal component analysis method, we preliminary screening seven families of the higher comprehensive quality seedling, they were 18#, 3#,33#,34#,36#,20# and 29# families.(5) The preliminary screening of the seven families of Euscaphis konishii biennial seedlings treated with low temperature instruction. The results showed that Euscaphis konishii is moderately cold resistance in plants. There is a significant correlation between soluble carbohydrate, SOD activity and MDA content in different temperature and stress. The ranking of capability of resistance to low-temperature stress is 18# > 29# > 36# > 3# > 33# > 34# > 20#.