【作者】 张亚宏；

【导师】 孙万仓；

【作者基本信息】 甘肃农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 甘蓝型油菜属于常异花授粉植物,一般认为自交不会产生衰退现象,但多代连续自交对甘蓝型油菜究竟有何影响鲜见报道。本试验以4个甘蓝型油菜品系为试验材料,研究了连续自交四代以后其主要经济性状、生育期、保护性酶活性等的变化,从而探讨自交对甘蓝型油菜的影响。主要研究结果如下:1.自交对甘蓝型油菜主要经济性状有显著影响。株高、分枝部位、有效分枝、主花序有效结角数、全株结角数及单株产量均随着自交世代的增加而减小,自交与主要经济性状之间的相关系数在-0.979～0.289之间变化,自交与株高、分枝部位、全株角果数、单株产量等呈显著负相关关系;而千粒重和角粒数受到的影响较小。03武240-1的生育期自交四代比开放授粉植株提前一周,其余三个品系无明显变化。2.参试品系自交世代的含油量、蛋白质含量与开放授粉相比显著降低(P<0.05),相关系数在-0.980～-0.724之间,呈高度负相关关系;而芥酸和硫甙含量的变化自交世代与开放授粉之间差异不显著。3.叶片保护酶活性SOD、CAT、APX均在初花期出现酶活性峰值,且自交世代明显低于开放授粉;POD活性在现蕾期和盛花期出现两次高峰,且均是开放授粉显著高于各自交世代;五叶期的POD同工酶四个品系均表现较小,但开放授粉的POD同工酶活性较自交世代的要强;EST同工酶在五叶期就很强,出现11条酶带,且开放授粉群体的EST活性强于自交世代,但是酶谱带数相同。4.参试品系的自交结实率随着自交世代的增加而减小,且显著低于OP(开放授粉群体),甘蓝型油菜的自交结实率与自交的相关系数在-0.992～-0.791之间变化,表现为高度负相关关系。品系03武240-1的自交四代出现不亲和现象(自交亲和指数<1)。连续严格自交使得甘蓝型油菜的自交结实率和自交亲和指数降低。5.本试验选用了29对油菜SSR引物,研究了连续严格的自交对甘蓝型油菜品系的影响。筛选出了6对具有多态性的引物,共检测出35个等位基因变异,每对引物检测出5～8个等位基因,平均5.83个。UPGMA聚类分析表明20份供试材料可划分为4大类,每一品系的开放授粉与其各自交世代聚为一大类。综上所述,自交对甘蓝型油菜性状有显著影响,表现出株高降低、产量下降、籽粒含油量和蛋白质含量降低、自交结实率降低、花期酶活性降低。说明严格的连续自交引起甘蓝型油菜自交后代的生活力减弱、品质下降、花期酶活性的降低。更多还原

【Abstract】 Brassica napus L. is an often cross-pollinated plant, and is not generally considered selfing recession, but it was little reported about effects of selfing on main traits of Brassica napus L. In this experiment four Brassica napus L.lines as the test materials, the changes of major economic traits, growth period, protective enzyme activity were studied after four years selfing, and the impact on Brassica napus L. by selfing were discussed. Key findings are as follows:1. Selfing had significant impacts on the main economic characters of Brassica napus L. Plant height, branch height, effective branch, No. of pods in the main inflorescence, No. of pods of whole-plant and yield per plant were reduced as self-generations increased. The correlation coefficient between the major economic traits and selfing is from -0.979 to 0.289, and selfing with plant height, branch height, the number of pods of whole-plant, yield and other traits was a significant negative correlation; while the impact on seeds per pods and 1000-seed-weight was smaller. In addition to 03wu240-1 participant strains , the growth period of Brassica napus L which was selfing four years was a week ahead of that of open cross pollination plants, the remaining three lines did not have any changes.2. Compared to open pollination, oil content and protein content of self-generations significantly decreased(P <0.05), the correlation coefficient was between -0.980 and -0.724, with a remarkable negative correlation; but the difference of changes of erucic acid and glucosinolate content between self-pollination generations and the opening-up was not significant.3. The SOD、CAT and APX had peak activity in the early anthesis, and the self-generation was significantly lower than open pollinated; POD activity in squaring period and anthesis had two peaks, and which both of the open pollinated were higher than those of self-generations respectively; the POD isozyme of four strains at five-leaf stage were smaller, but the activity of the POD isoenzyme of open pollination were stronger than those of self-generations;While the EST isozyme of the open pollinated were stronger than self-generations, with 11 bands.4. The seed-setting rate decreased as the self-generation increased, and which is significantly lower than OP (open pollinated groups).The correlation coefficient was between the -0.992 and -0.791.The 03wu240-1 turned into self imcompatible in the fourth self-generation(SC index <1). Strictly selfing made the self compatible index and seed-setting rate of Brassica napus L down.5. The impact on Brassica napus L was studied after continuous strict selfing with29 pairs SSR primer. Six pairs polymorphism SSR primer were obtained, with a total of 35 alleles variations, each primer detected five to eight allele, an average of 5.83. UPGMA clustering analysis showed that 20 tested materials can be divided into four broad categories, in each strains the open cross pollination with their responding self-generations clustered together.In a word, selfing had a significant impact on Brassica napus L traits, which led to the lower height and yield, the decrease of grain oil and protein content, the decline of seed-setting rate, the reduction of enzyme activity at anthesis stage.更多还原