【作者】 黄明波；

【导师】 杨克诚； 杨俊品；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 玉米纹枯病是世界上玉米产区广泛发生、严重危害玉米产量的病害之一。现已成为影响西南地区玉米生产最严重的病害。多年来玉米抗纹枯病育种主要靠表型鉴定选择,而近年来发展起来的分子标记辅助育种,也停留在标记鉴定、定位、作图等基础环节上,在育种中的应用还很不够。因此,本研究针对玉米纹枯病危害日益严重、纹枯病抗源又极为匮乏以及选育方法极待完善的现状,利用抗玉米纹枯病低代育种群体,采用常规遗传育种研究和现代分子生物学技术相结合的方法,对抗性表型变异、农艺性状相关性、标记辅助选择育种等方面,进行了较为系统的探索研究,以期为玉米纹枯病育种提供一定的理论依据。取得的主要结果如下:1.接种鉴定结果表明,CML270的病情指数为13.59%,按抗感程度划分标准,属于高抗玉米纹枯病自交系;478的病情指数为83.62%,按抗感程度划分标准,属于高感纹枯病自交系;F1的病情指数为48.96%,介于P1、P2之间,表现为中抗-中感。由此可以看出,两亲本间在抗感程度上存在明显的差异,进一步验证了CML270为高抗玉米纹枯病自交系。2.单点方差分析结果表明,病斑高、株高和穗位高等性状在基因型间的差异均达极显著水平,说明玉米纹枯病受基因型影响。两地联合方差分析表明,地点间差异表现为极显著,说明环境对玉米纹枯病的影响极为明显;家系间、家系×地点差异表现为显著,说明家系间和家系×地点对病情指数影响明显。而地点内区组间差异不显著,说明同一试验地点内不同区组对纹枯病病情指数无明显影响。由此可以看出,玉米纹枯病病情指数受环境影响要比基因型及基因型与环境互作影响大得多。3.F_2:4群体的病情指数与部分农艺性状的相关分析结果表明,病情指数与穗位高呈极显著负相关,说明玉米穗位较高相应病情指数较低;穗位较低病情指数相应较高。因此,在抗玉米纹枯病育种中,通过对穗位高的适度选择,可能有助于提高玉米对纹枯病的抗性。4.穗高/株高与田间抗性鉴定比较表明,郫县点田间抗性鉴定中共筛选出37个中抗以上的家系,这些中选家系的穗位高/株高大多都在0.32～0.53之间,且多数（26个）家系穗位高/株高在0.40以上。雅安点筛选出38个中抗以上的家系,穗位高/株高在0.29～0.44之间,多数（31个）家系穗位高/株高在0.35以上。两点比较结果均与相关分析结果基本一致。充分说明,利用穗位高/株高进行表型选择对提高抗玉米纹枯病特性将会起到一定的作用。至于选择指标是否以穗位高/株高0.35-0.40为宜,尚值得进一步研究。5.单标记、双标记对两点标记选择结果比较表明,phi116标记在两个试验点共检测到54个带型为A的家系,其中郫县点经接种鉴定表现为抗性家系25个（占46.30%）;雅安点抗性家系18个（占32.48%）。umc1044标记在两个试验点共检测到59个带型为A的家系,其中郫县点抗性家系21个（占35.60%）;雅安点抗性家系16个（占26.42%）。两个标记联合进行选择,郫县点经接种鉴定表现为抗性家系17个（占31.13%）;雅安点经接种鉴定表现为抗性家系16个（占29.34%）。由上可以看出,利用双标记选择明显比单标记选择准确性高,且试验环境不同,鉴定结果有较大的差别,说明用多个标记、多种环境比用单个标记、单一环境的选择压力更大,选择效果可能更好。6.对部分抗性家系的分析表明,在抗性家系中多数单株的病级为0-3级,而5-9级的单株较少。如家系1114-1共调查15株,其中有6个单株的病级为0级,有2个单株的病级为1级,2个单株的病级为2级,抗病指数为33.33%;家系1124-1有7个单株的病级为0级,有2个单株的病级为1级,有3个单株的病级为5级,抗病指数为29.62%;家系1160-1有6个单株的病级为0级,1个单株的病级为1级,有1个单株的病级为3级,抗病指数为36.30%,进一步证明利用本课题组现有连锁标记辅助选择具有一定的可靠性。更多还原

【Abstract】 Banded leaf and sheath blight(BLSB) is one of the most harmful diseases with a globally harmfulness.It is also a serious diseases in China especially in the southwest mountain areas of China.Over the years the study on Banded leaf and sheath blight are still in the stage of identification tag,location,mapping and other infrastructure areas,the application in breeding still is very inadequate.That’s the reason why the germplasm is insufficient for resistance to the disease.In our research,conventional genetic breeding and modern molecular biology techniques were combined to study on MAS of the disease with a view to provide technical support and material with highly resistance for the breeding.The main results were summaried as follow:1.The disease index of CML270 and 478 is 13.59%and 83.62%,respectively.According to the identification of resistant for BLSB,the maize inbred line CML270 was resistant to maize BLSB,otherwise 478 is highly susceptible.The disease index of F1 was 48.96%, ranged from that of P1 to P2.It showed that there are significant differences in the resistant to BLSB between the two inbred lines.It also verify that CML270 was an inbred lines with high resistance to sheath blight.2.The result of ANOV of each location showed that variance of the 145 families were significant in plant height,ear height and BLSB height.It showed that the resistance of the families were affected by the genotype.The result of combine ANOV of two locations showed that variance of the location were significant in plant height,ear height and height.It showed that the resistance of the families were affected by the locations.The results showed that the resistant of the families were affected by the genotype,envrioment and genotype×envrioment.3.The result of correlation analysis showed that the disease index is significant correlated with the plant height and ear height negatively.It is suggested that the families with higher plant and ear were more resistant to the disease.In breeding application,we can selecet resistant families by selecting the families with higher plant and ear.4.37 high resistance or resistance families were selected according to the results of field experiment in Chengdu.The value of Ear height/height of these families ranged from 0.36 to 0.5.The value of Ear height/height of 26 of the 37 families were bigger than 0.40. 38 high resistance or resistance families were selected according to the results of field experiment in Ya’an.The value of Ear height/height of these families ranged from 0.29 to 0.44.The value of Ear height/height of 31 of the 38 families were bigger than 0.40.It is suggested that it is effective to select the families with high resistance or resistance by using the value of Ear height/height.If the the value of Ear height/height between 0.35 and 0.40 could be used as the selection criterion needs futher study.5.54 families were detected to have the A band(resistance band) with the marker Phi116,25 (46.30%) and 17(31.48%) of these families were identified to resistance family according to the results of field experiment in Chengdu and Ya’an,respectively.59 families were detected to have the A band(resistance band) with the marker Umc1044,21(35.60%)and 15(25.42%) of these families were identified to resistance family according to the results of field experiment in Chengdu and Ya’an,respectively.When both of the 2 markers were combined,only 14(25.93%) and 12(20.34%) families were were identified to resistance family according to the results of field experiment in Chengdu and Ya’an,respectively.It is more accuracy to select by using double-tag than using a single tag.6.The disease-resistant grade level of the individuals of the 12 resistance families were analysis.The majority of the individuals of these families belongs to the 0-3 grade level, the minority of the the individuals of these families belongs to the 5-9 grade level.For instance,a total of 15 individuals of the family 1114-1 were investigated,6,2 and 2 plants belongs to grade level 0,1,and 2,respectively,with a disease-resistant index of 33.33%.A total of 15 individuals of the family 1124-1 were investigated,7,2 and 3 plants belongs to grade level 0,1,and 5,respectively,with a disease-resistant index of 29.62%.A total of 15 individuals of the family 1160-1 were investigated,6,1 and 1 plants belongs to grade level 0,1,and 2,respectively,with a disease-resistant index of 36.30%.It is suggested that the marker assistant selection is reliable by using the markers Phi116 and Umc1044.更多还原