【作者】 乌日娜；

【导师】 慈忠玲；

【作者基本信息】 内蒙古农业大学 ， 林木遗传育种， 2011， 硕士

【摘要】 本研究通过人工控温实验方法,利用形态学、生理学技术,测定了11个不同秋眠等级苜蓿品种的抗寒反应及差异,并探讨了苜蓿秋眠性与抗寒性的关系。得到如下结果:(1)通过4组不同低温胁迫处理,低秋眠级品种比高秋眠级品种的抗寒性要强,-7℃、6h的低温胁迫适合于比较不同秋眠级品种间的抗寒性差异。(2)低温胁迫下,不同秋眠等级苜蓿品种膜透性随着低温胁迫程度的加重而增大,秋眠型苜蓿品种膜透性增加低于其他类型品种;丙二醛(MDA)含量的变化总体上呈上升趋势,而不同秋眠类型品种间在丙二醛积累上存在差异,秋眠等级高的品种其丙二醛积累的量大,秋眠类型苜蓿的积累量较小。游离脯氨酸积累随胁迫强度和材料抗寒性的不同表现出一定的规律性。游离脯氨酸积累随着胁迫强度的加重而增高,秋眠级别越高其积累的量越小,秋眠类型苜蓿品种脯氨酸含量变化最大,而极非秋眠型苜蓿品种最小。过氧化物酶(POD)和超氧化物歧化酶(SOD)活性显著提高,而增幅较大的为秋眠类型品种,非秋眠和极非秋眠类型品种提高幅度相对较小。(3)不同秋眠等级苜蓿品种的幼苗子叶到第1真叶距离与苜蓿的秋眠级极显著正相关,不同秋眠类别内苜蓿品种的幼苗子叶到第1真叶之间的距离差异并不显著。同样,第1~2真叶距离与苜蓿的秋眠等级正相关,达到极显著水平,但是不同秋眠类别内苜蓿品种幼苗子叶到第1真叶距离差异并不显著。因此以幼苗幼苗子叶到第1真叶距离和第1~2真叶距离测定秋眠级只能是初步的估测,而不能精确测定。(4) 5个品种的细胞结构紧密度(CTR)表现为:Maverick(FD=1)﹥5246 (FD=3)﹥Pierce(FD=8)﹥UC-1887(FD=10)﹥UC-1465(FD=11),秋眠型品种表现了较好的细胞结构紧密度,抗寒性强。细胞结构疏松度表现为:UC-1465(FD=11)﹥UC-1887(FD=10)﹥Pierce(FD=8)﹥5246 (FD=3)﹥Maverick(FD=1),极非秋眠类型品种细胞结构疏松度高于其他品种。更多还原

【Abstract】 In this study, we used the man-controlled temperature method and morphology and physiology techniques to determine the cold responses and discrepancies of alfalfa at different fall dormancy levels ,11 varieties were included , then discussed the relationship between the fall dormancy and cold resistance. The results are as follows:Under 4 low temperature stresses, the alfalfa’s cold resistance at low level fall dormancy is stronger than the high level’s, and -7℃with 6-hour low temperature stress is more suitable for the comparison of the different fall dormancy species’cold resistance.Under the cold stress, the membrane permeability of the fall dormancy alfalfa at different levels is bigger with the increase of the cold stress , and the increase of the fall dormancy alfalfa is lower than others. The whole trend of content of MDA in alfalfa at different fall dormancy is increasing under low temperature stress, and the content of MDA in different varieties is difference. The accumulation of MDA in high level fall dormancy alfalfa is more than others.Under the low temperature stress, the accumulation of the free proline with different stress intensity and cold resistance of materials shows some regularity. The accumulation of free proline is increase with lower temperature stress, the higher level of the fall dormancy will be less. The content of the proline has the biggest change while the extreme-non-fall dormancy type’s change is the smallest.The low temperature stress makes the POD and SOD in different varieties of fall dormancy alfalfa significantly increase, especially the fall dormancy, but the non- and extreme- non fall dormancy is not very obvious.The distance of the seedling cotyledon to the first leaf of the fall dormancy was significantly positively related to the categories of different fall dormancy alfalfa. The distance of the seedling cotyledon to the first leaf among the difference categories was not significant. The distance between 1st-2nd leaf is positive related with fall dormancy of alfalfa and has reached a significant level. Through the specific analysis between different alfalfa variety’s 1st-2nd leaf distance, only provide the preliminary estimates, it can not exactly mearsured.The CTR research in 5 varieties shows: Maverick ( FD=1 )﹥5426(FD=3)﹥Pierce(FD=8)﹥UC-1887(FD=10)﹥UC-1465(FD=11) , The fall dormancy categories show the good tightness of cell structure and cold resistance. Cell porosity shows:UC--1465(FD=11)﹥UC-1887(FD=10)﹥Pierce(FD=8)﹥5426(FD=3)﹥Maverick(FD=1)Extreme-non fall dormancy loose cell structure is better than other varieties.更多还原